STRESS-NG(1) General Commands Manual STRESS-NG(1) (NAME) stress-ng - stress (SYNOPSIS) stress-ng [OPTION [ARG]] ... (DESCRIPTION) stress-ng . . stress-ng (CPU) (floating point) (integer) (bit manipulation) (cache) (vector instructions) (control flow) . stress-ng (thermal overruns) (system thrashing) . stress-ng . stress-ng (throughput) . . stress-ng (root) (OOM) (stressors) . stress-ng ionice . sysconf(_SC_NPROCESSORS_CONF) (online CPUs) . . ( ). (OPTIONS) stress-ng: --abort ( ) . -A, --aggressive swap (cache) (CPU affinity) . (user time) (system time) . madvise / ( swap ) P-state . -a N, --all N, --parallel N N . N (online) . N . N ( )..SH " (OPTIONS)" --autogroup nice(2) /proc/self/autogroup niceness . CONFIG_SCHED_AUTOGROUP CFS sched(7) . . -b N, --backoff N (stress worker) N . . --buddystat S S buddy (fragmentation) . . --buildinfo (linker) C . --c-states C-state . --change-cpu (stressors) (CPU) . . / (sock sockmany udp ) (switch pipe ). --class name . : compute cpu cpu-cache device fp gpu hot interrupt integer ipc io filesystem memory network os pipe scheduler search signal sort tlb vector vm. `get` `os` . `lsearch` `cpu` `cpu-cache` `memory` `search` . --sequential . ( --class vm\?) . --compact-memory (compact) (root) ( ). --config stress-ng . -n, --dry-run . (no-op). --dentrystat S S (directory entries) (negative dentry) . . --exercised . --exercise-feature list : --exercise-features branch,registers . --all --permute --seq . : \? atomic (atomic operations) backend-bound-rob (ROB) bogo-ops-stable bogo-ops branch (branch) branch-miss (branch misses) bus-lock (split lock) chaotic-load cipher (cipher) context-switches (context switch) cpu-shift / cpu-bit (and or xor not) cpu-heavy-ops (pipeline) cpu-instructions cpu-migrations cpu-opcode (opcodes) cpu-vector crypto d-cache (data cache) d-cache-l1-read (L1) d-cache-l1-write (L1) d-cache-ll-read (LLC) d-cache-ll-write (LLC) d-cache-miss ( ) d-cache-prefetch (prefetch) ( ) d-cache-read-miss d-cache-write-miss d-tlb-read-miss TLB ( ) d-tlb-write-miss TLB ( ) directory file-lock frontend-decoder (frontend decoder) filemap-page-cache page cache fp (floating point) fp-complex fp-decimal fp-division fp-ops frontend-bound-bandwidth hash heap heap hot-package (package) hotplug ( ) i-cache (instruction cache) i-tlb-read-miss TLB ( ) integer integer-division integer-ops hash heap heap hot-package interrupt (interrupt) io-async / (I/O) io-read I/O io-therm I/O I/O io-wait I/O io-write I/O ioport-read I/O (ioport) ioport-write I/O (ioport) ipc (IPC) kmalloc (kmalloc) load-average (load average) ( ) lock-contention (lock contention) maple-tree-read maple tree ( ) maple-tree-write maple tree ( ) memory-bus memory-bound / memory-cmp ( ) memory-copy memory-load (load) memory-stall memory-store (store) memory-stream (streaming) / memory-misaligned / (misaligned) mmap-lock (mmap) oom (out-of-memory) page-faults-kernel (page faults) page-faults-major (major) page-faults-minor (minor) page-faults-user power-core power-package (package) power-uncore (uncore) registers (CPU registers) speculation-mispredict (speculation misprediction) stack (stack) string (string) swap (swapfile) syscall-rate system-time timer tlb (TLB) tlb-flush (TLB flushes) user-time virt vmalloc vmalloc writeback-dirty-folio (dirty folio pages) writeback-dirty-inode inode --exercise-library list : --exercise-library pthread,z libpthread libz. --all --permute --seq . : lB lB l lx. \? acl libacl ( ) aio libaio (/ ) apparmor libapparmor (AppArmor) bsd libbsd ( C BSD) crypt libcrypt ( ) dl libdl ( ) egl libegl ( API OpenGL) gbm libgbm ( ) glesv2 libglesv2 (OpenGL ES 2.0) gmp libgmp ( GNU) IPSec_MB libIPSec_MB ( Intel (R) IPSec) jpeg libjpeg ( JPEG) judy libjudy ( ) lzma liblzma (/ lzma) m libm ( ) md libmd ( BSD) mpfr libmpfr ( GNU) nl libnl ( Netlink) pthread libpthread ( POSIX) rt librt ( POSIX) sctp libsctp ( SCTP) xxhash libxxhash ( ) z libz (/ z) --exercise-syscall list : --exercise-syscall mmap,fork mmap fork. \? . --all --permute --seq . --ftrace ( Linux). ftrace debugfs stress-ng . ftrace . -h, --help . --ignite-cpu (CPU). /sys (root) . x86 Intel P-State Linux . --interrupts . . --ionice-class class ionice ( Linux). idle () besteffort be realtime rt . --ionice-level level ionice ( Linux). idle 0 . besteffort realtime 0 ( ) 7 ( ) . ionice(1) . --ios / / ( Linux). -I S, --iostat S S / (I/O) stress-ng . --temp-path . Linux . : Inflight / Rd K/s Wr K/s Rd/s Wr/s -j jobfile, --job jobfile jobfile. jobfile stress-ng ( -- ) . # . : run sequential # run stressors sequentially verbose # verbose output metrics-brief # show metrics at end of run timeout 60s # stop each stressor after 60 seconds # # vm stressor options: # vm 2 # 2 vm stressors vm-bytes 128M # 128 MB available memory shared by 2 vm stressors vm-keep # keep vm mapping vm-populate # populate memory # # memcpy stressor options: # memcpy 5 # 5 memcpy stressors job run : run sequential - run parallel - `run parallel' . --keep-files . . . -k, --keep-name stress-ng stress-ng . -K, --klog-check (kernel log) . root . --ksm KSM (kernel samepage merging) ( ). (de-duplication) () . --limit-as ( ) rlimit(2) RLIMIT_AS . ( 1G ) 20% . --limit-data ( heap) rlimit(2) RLIMIT_DATA . ( 128M ) 5% . --limit-stack (stack) rlimit(2) RLIMIT_STACK . ( 2M ) 1% . --log-brief stress-ng (PID) . --log-brief . -L filename, --log-file filename stdout . fsync . --log-lockless (verbose) (contention) . . --make-it-fail (fault injection) ( /proc/self/make-it-fail). sysfs /sys/kernel/debug . --maximize . . --max-fd N ( ) . stress-ng RLIMIT_NOFILE . 50% . stress-ng . --mbind list NUMA NUMA () . set_mempolicy(2) MPOL_BIND . NUMA ( 0 N - 1) . `-' NUMA : --mbind 0,2-3,6,7-11 -M, --metrics (bogo operations) . . bogo-ops . : bogo ops . <<>> bogo operation . . real time (secs) ( ) . . usr time (secs) ( ) . sys time (secs) ( ) . bogo ops/s (real time) bogo . . bogo ops . bogo ops <<>> . bogo ops/s (usr+sys time) bogo . bogo ops . (cache) I/O . CPU used per instance (%) CPU . 100% . (thread) 100% . RSS Max (KB) resident set size (RSS) ( ) . --metrics-brief ( CPU used per instance ). --minimize . . --no-madvise 0.02.26 stress-ng mmap(2) munmap(2) madvise(2) madvise (vm) . --no-advise ..TP --no-madvise-opts madvice-list madvise(2) . stress-ng madvise mmap(2) munmap(2) . ( ) : cold dodump dofork dontdump dontfork dontneed free hugepage mergeable nohugepage normal pageout populate-read populate-write random sequential unmergeable willneed. --no-oom-adjust (out-of-memory) . stress-ng . . --no-rand-seed stress-ng (seed) . . --oom-avoid (OOM killer) . (swapping) . --oom-avoid-bytes N . ( 2M ) %5 ( . ) . --oom-avoid . . --oom-no-child (OOM) . OOM OOM bogo-op . -O, --oomable (OOM) . OOM . . --page-in (page in). bigheap mmap vm . . mincore(2) . --pathological . (hang) . . . : bad-ioctl bind-mount cpu-online mlockmany oom-pipe smi sysinval watchdog. --pause T T . . . --perf perf. (caveat emptor) perf_event_open(2) : " ! ". . CAP_SYS_ADMIN CAP_SYS_ADMIN /proc/sys/kernel/perf_event_paranoid . --permute N N . N . N . N ( ). 2^20 . --with --class . --progress --sequential. -q, --quiet . -r N, --random N N . N N . --randprocname . . --rapl (RAPL) . x86 (root) RAPL . RAPL . --raplstat S S RAPL . x86 (root) RAPL . --resctrl p1[,p2,..,pn],s1[,s2..,sm] ( ARM MPAM) p1..pn n p1..pn : pN=node[:cachelevel]:hexbitmask:bandwidth : o pN N p1 o node o cachelevel ( MPAM L3 ) o hexbitmask o bandwidth MPAM : p1=1:L3:fff:50 s1..sm m : stressor-name=stressor-instances@pN : o stressor-name o stressor-instances pN . o pN pN resctrl p1 matrix : matrix=0-1,5,8,12-14@p1 resctrl : p1 L3 . p2 L3 . stream stream p1 p2 . sudo stress-ng --resctrl p1=1:l3:7:10,p2=1:ff8:90,\ stream=0-1@p1,stream=2@p2 --stream 3 resctrl resctrl sysfs EINVAL . . --sched scheduler ( ). : stress-ng --sched which --sched-prio prio ( ). . --sched-period period (period) deadline ( ). ( )..TP --sched-runtime runtime runtime deadline ( ). 99999 ( ) . --sched-deadline deadline deadline deadline ( ). 100000 ( ) . --sched-reclaim CPU deadline ( ). --seed N (seed) . . --settings . --sequential N . N . N (online) . N . N ( ). (OPTIONS) --timeout . --skip-silent . --smart S.M.A.R.T. ( ). root Self-Monitoring, Analysis and Reporting Technology . . --sn ( 2.412e+01) . --status N N (reaped) SIGARLM . --stderr stderr. 0.15.08 stdout stderr . 0.15.08 . --stdout stdout. 0.15.08 . --stderr . --stressor-time ( -v) (debug) : stressor [start|finish] HR:MN:SS.HS YYYY:MM:DD HR MN SS HS YYYY MM DD . localtime(2) Epoch . --stressors . --sync-start . --syslog ( -v) syslog. --taskset list (CPU affinity) stress-ng ( sched_setaffinity(2) ). ( 0 N - 1) . '-' : --taskset 0,2-3,6,7-11 : even odd all random packageN package N /sys/devices/system/cpu/cpu*/topology/package_cpus_list clusterN package N /sys/devices/system/cpu/cpu*/topology/cluster_cpus_list dieN package N /sys/devices/system/cpu/cpu*/topology/die_cpus_list coreN package N /sys/devices/system/cpu/cpu*/topology/core_cpus_list --taskset-random (CPU affinity) ( ) 400Hz . --temp-path path stress-ng . stress-ng . --thermalstat S S . ( ) ( ) . --thrash root . (thrasher) (page-in) . page cache (slab) pagecache NUMA . (swap thrashing) (over-committed) . -t N, --timeout T T . s m h d y . (timeout) SIGALRM swap ( ) . 0 stress-ng . . --timer-slack N (timer slack) N ( ). (wakeups) . . 0 timer-slack 50000 . --times . . --timestamp . --tz (thermal zones) ( ). . -v, --verbose . --verify . . `fail' . --verifiable --verify . -V, --version stress-ng toolchain stress-ng ..TP --vmstat S S (paging) / (block I/O) (context switch) CPU . vmstat(8) . UNIX . --vmstat-units [ k | m | g | t | p | e ] vmstat (k) (m) (g) (t) (p) (e) . . -w, --with list --all --seq --permute . cpu hash nop vm () : stress-ng --seq 5 --with cpu,hash,nop,vm --timeout 1m -x, --exclude list ( ) . --class --sequential --all --random . CPU numa search: stress-ng --class cpu --all 1 -x numa,bsearch,hsearch,lsearch -Y, --yaml filename YAML `filename' . : Access () --access N N ( ) access(2) faccessat(2) . --access-ops N access N bogo . Process accounting ( ) --acct N N acct(2) . . 16MB . CAP_SYS_PACCT . --acct-ops N N bogo . POSIX Access Control List ( ) --acl N N ACL user group other . --acl-rand ACL ACL ( ) . --acl-ops N acl N bogo acl . Affinity ( ) --affinity N N (CPU affinity) ( sched_setaffinity(2) ). (cache) (context switch) . --affinity-delay N CPU N . CPU N (yield) CPU (spin) . 0 . --affinity-ops N affinity N bogo affinity . --affinity-pin CPU (pin) . CPU CPU . --affinity-procs N affinity . --affinity-rand CPU . --affinity-sleep N CPU N (sleep). Kernel crypto AF_ALG API ( ) --af-alg N N AF_ALG ( ) . (cipher) rng aead . --af-alg-dump /proc/crypto (stdout) (dump). --af-alg-ops N af-alg N AF_ALG . --af-alg-type [ all | ahash | shash | skcipher | rng | aead ] `all' . Asynchronous I/O (POSIX AIO - / ) --aio N N POSIX aio / . (cache) / . / . --aio-ops N / POSIX N bogo / . --aio-requests N / POSIX . Asynchronous I/O (Linux AIO - / ) --aiol N N aio io_setup(2) io_submit(2) io_getevents(2) io_destroy(2) / 4K . / . --aiol-ops N / N bogo / . --aiol-requests N / . Alarm () --alarm N N alarm(2) MAXINT 0 . . --alarm-ops N N bogo alarm . AppArmor --apparmor N N AppArmor . (root) . AppArmor CAP_MAC_ADMIN . --apparmor-ops AppArmor N (bogo operations). (Atomic stressor) --atomic N N __atomic_*() GCC N . GCC 4.7.4 . (front end cache stalls) (cache references) . . --atomic-ops N N (bogo atomic operations). (Bad alternative stack stressor) --bad-altstack N N SIGSEGV SIGBUS SIGSEGV/SIGBUS . : o (unmapping) . o . o NULL. o . o . o (text segment) . o . o VDSO . o /dev/zero. o SIGBUS. --bad-altstack-ops N N SIGSEGV. ioctl (Bad ioctl stressor) --bad-ioctl N N ioctl(2) ( _IOR) ioctl ( _IOR PROT_NONE) . (page size) NULL PROT_NONE . --pathological . --bad-ioctl-alldev ioctl ( /dev/i2c-0) ( /dev/i2c-*) . --bad-ioctl-method [ inc | random | random-inc | stride ] ( ) ioctl random-inc . bad-ioctl : inc ioctl random ioctl random-inc ioctl random-stride ioctl --bad-ioctl-ops N ioctl N ioctl. (Bessel functions) --besselmath N N . . --besselmath-ops N N . --besselmath-method method . : all j0 (double precision) j1 (double precision) jn n ( n = 5 ) (double precision) j0f (float precision) j1f (float precision) jnf n ( n = 5 ) (float precision) j0l (long double precision) j1l (long double precision) jnl n ( n = 5 ) (long double precision) y0 (double precision) y1 (double precision) yn n ( n = 5 ) (double precision) y0f (float precision) y1f (float precision) ynf n ( n = 5 ) (float precision) y0l (long double precision) y1l (long double precision) ynl n ( n = 5 ) (long double precision) Big heap -B N, --bigheap N N heap . (OOM killer) . OOM OOM killer . --bigheap-bytes N heap N bigheap. (%) b k m g . --bigheap-growth N heap . 4 K 64 MB . 64 K . --bigheap-mlock mlock(2) . mlock(MCL_FUTURE) swap . --bigheap-ops N big heap N bogo. Binderfs --binderfs N N binderfs mount unmount . binder 256 ioctl(2) BINDER_CTL_ADD . --binderfs-ops N N binderfs. Bind mount --bind-mount N N /bin bind mount . . . CAP_SYS_ADMIN . --bind-mount-ops N N bogo bind mount. Bitonic sort --bitonicsort N N (bitonic sort) . --bitonicsort-ops N N bogo. --bitonicsort-size N 262144 (256 x 1024) . --bitops N N . <> (Sean Eron Anderson) Hacker's Delight (Henry S. Warren, Jr.) . --bitops-ops N N bitop. --bitops-method method bitops. bitops . bitops : all bitops . abs . : . bswap . : (intrinsic) . bswap . countbits . : popcount. clz . : log2 popcount clz. ctz . : Gaudet clz popcount. cmp -1 0 1 . : . log2 . : (branching) OR . max . : xor . min . : xor . parity (parity) . : xor xor parity. pwr2 . - 1. rnddnpwr2 . : or ctz. rnduppwr2 . : or ctz. reverse . : bitreverse32. sign . : (branchless) (negation). swap . : xor. zerobyte . : . Branch --branch N N 1024 (branch prediction) . --branch-jumps [ 64 | 128 | 256 | 512 | 1024 | 2048 ] . (branch miss rate) . --branch-ops N N x 1024 . Brk --brk N N (data segment) brk(2) . (touch) . . (OOM killer) . OOM killer . --brk-bytes N brk N brk. (%) b k m g . --brk-mlock mlock(2) brk . mlock(MCL_FUTURE) swap brk . --brk-notouch (touch) . . --brk-ops N brk N bogo brk. (Binary search stressor) --bsearch N N bsearch(3) . . . --bsearch-method [ bsearch-libc | bsearch-nonlibc | ternary ] libc bsearch non-libc bsearch (3-day ternary search). libc non-libc . --bsearch-ops N bsearch N bogo bsearch. --bsearch-size N ( ) bsearch. 1 K 64 M . (bubblesort stressor) --bubblesort N N bubblesort . --bubblesort-method [ bubblesort-fast | bubblesort-naive ] bubblesort (naive) bubblesort. . --bubblesort-ops N bubblesort N bogo bubblesort. --bubblesort-size N . (Cache stressor) -C N, --cache N N (thrash) . CPU / (hit- miss) / . : (cache misses) matrix-3d --matrix-3d-zyx . --cache-badpage (cache flush) (). --cache-cldemote (cache line demote) ( x86). x86 x86 (no-op) . --cache-clflushopt ( x86). x86 x86 (no-op) . --cache-clwb (cache line writeback) ( x86). x86 x86 (no-op) . --cache-enable-all cldemote clflushopt fence flush sfence prefetch. --cache-fence (write serialization) ( x86). x86 (no-op) . --cache-flush ( x86). x86 (no-op) . --cache-level N (1 = L1 2 = L2 3 = L3/LLC ()). . --cache-no-affinity (processor affinity) --cache . --cache-ops N thrash N bogo cache thrash. --cache-permute . --cache-enable-all . --cache-prefetch (read prefetch) . --cache-prefetchw (redundant write prefetch) . --cache-sfence sfence ( x86). x86 (no-op) . --cache-size N N . b k m g . --cache-ways N (cache ways) . . (Cache hammering stressor) --cachehammer N N / L3 L3 . --cachehammer-method [ permute | random ] (random) permute . --cachehammer-numa NUMA . NUMA . --cachehammer-ops N N cache hammer. (Cache line stressor) --cacheline N N (cache line) . . N N . (stalls) (misses) . --cacheline-affinity (CPU affinity) cacheline CPU . . --cacheline-method method . . : all CPU . adjacent . atomicinc . bits . copy . inc . mix . rdfwd64 . rdints . rdrev64 . rdwr . --cacheline-ops N cacheline N cacheline. (Process capabilities stressor) 5 --cap N N capget(2) ( ). --cap-ops N N (bogo) cap. Cgroup (Cgroup stressor) 5 --cgroup N N bogo cgroup (mount) cgroup cgroup cgroup (umount) . cgroup v2 . --cgroup-ops N N (bogo) cgroup. Chattr (Chattr stressor) 5 --chattr N N ioctl(2) EXT2_IOC_SETFLAGS . (racy) chattr N chattr ( ). --chattr-ops N N (bogo) chattr. Chdir (Chdir stressor) 5 --chdir N N chdir(2) . --chdir-dirs N chdir N . 8192 64 65536 . --chdir-ops N N (bogo) chdir. Chmod (Chmod stressor) 5 --chmod N N (mode bits) chmod(2) fchmod(2) . N (contention) . . --chmod-ops N N (bogo) chmod. Chown (Chown stressor) 5 --chown N N chown(2) . N . --chown-ops N chown N (bogo) chown(2). Chroot (Chroot stressor) 5 --chroot N N chroot(2) chroot . CAP_SYS_ADMIN . --chroot-ops N chroot N (bogo) chroot(2). (Complex hyperbolic functions stressor) 5 --chyperbolic N N libm sinh cosh tanh complex float complex double complex long double . (bogo-operation) 10000 . --chyperbolic-method function . . : lB2 lB l lx. all ccosh ( complex double) ccoshf ( complex float) ccoshl ( complex long double) csinh ( complex double) csinhf ( complex float) csinhl ( complex long double) ctanh ( complex double) ctanhf ( complex float) ctanhl ( complex long double) --chyperbolic-ops N N (bogo-operation). (Clock stressor) --clock N N POSIX. clock_getres(2) clock_gettime(2) clock_nanosleep(2) . (busy poll) . (context switching) . --clock-ops N N (bogo). Clone (Clone stressor) --clone N N ( clone(2) clone3(2)) . 8192 (zombie) (reaped) . ( clone ) (FIFO) . clone clone . clone . --clone-max N N . N . --clone-ops N clone N (bogo) . Close (Close stressor) --close N N (race conditions) . ..TP --close-fds N fd ( ) . --close-ops N close N bogo close. Swapcontext --context N N (thread) swapcontext(3) (context switching) . . --context-ops N context N bogo. bogo swapcontext . (Copy file) --copy-file N N copy_file_range(2) . . . copy_file_range(2) (sync) . --copy-file-bytes N . b k m g . --copy-file-io-bytes N I/O copy_file_range(2) . --copy-file-ops N N copy_file_range(). (CPU) -c N, --cpu N N CPU. --cpu-method . -l P, --cpu-load P P . ( ) . (%load) (100% - load%) . . bogo bogo . : --cpu . --cpu-load-slice S : --cpu-load . (busy) (idle) . . S ( 30- ). . S ( ). S . --cpu-load --cpu-load-slice . / . : --cpu . --cpu-method method . . : Method Description all ackermann : A(3, 7) : A(m, n) = n + 1 if m = 0; A(m - 1, 1) if m > 0 and n = 0; A(m - 1, A(m, n - 1)) if m > 0 and n > 0 hanoi . apery (3) 1/(n ^ 3) 1.0x10^14 bitops bithack : (parity) callfunc C (unwind) cfloat cdouble (double) clongdouble (long double) collatz f(n) = n / 2 ( n ) f(n) = 3n + 1 ( n ). correlate x crc16 CCITT CRC16 decimal32 ( GCC) decimal64 ( GCC) decimal128 ( GCC) dither - x div8 div16 div32 div64 div128 double euler e n = (1 + (1 / n)) ^ n explog n = exp(log(n) / 1.00002) factorial fibonacci ... fft fletcher16 (naive) float float16 float32 float64 float80 float128 floatconversion float double long double. gamma - (1 + 1/2 + 1/3 + 1/4 + 1/5 ... + 1/n) ln(n) n = 80000. gcd .. (GCD) gray hamming H(8,4) . . d1..d4 : p1 = d2 + d3 + d4 p2 = d1 + d3 + d4 p3 = d1 + d2 + d4 p4 = d1 + d2 + d3 hanoi . ackermann . hyperbolic sinh() x cosh() + sinh(2) + cosh(3) float double long double = 0 2 idct (IDCT) 8 x 8. int8 . int16 . int32 . int64 . int128 ( GCC). int32float . int32double . int32longdouble . int64float . int64double . int64longdouble . int128float ( GCC). int128double ( GCC). int128longdouble ( GCC). int128decimal32 ( GCC). int128decimal64 ( GCC). int128decimal128 ( GCC). intconversion int16 int32 int64. ipv4checksum IPv4. jmp > < == jmp. lfsr32 x^32 + x^31 + x^29 + x + 1. 2^32 - 1 ( ). ln2 ln(2) : 1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 ... logmap Xn+1 = r x Xn x (1 - Xn) r > ~ 3.56994567 longdouble . loop . matrixprod x (double). x86 (cache) . nsqrt sqrt() long double -. omega e^ = 1 n+1 = (1 + n) / (1 + e^n). parity Stanford Bit Twiddling Hacks. : (naive) ( ) __builtin_parity(3). phi . pi . prime (brute force). psi ( ) . queens . rand rand() rand MWC . MWC multiply-with-carry : x(n) = 36969 x x(n - 1) + carry, y(n) = 18000 x y(n - 1) + carry mod 2 ^ 16 2 ^ 60 . rand48 drand48(3) lrand48(3). rgb RGB YUV RGB (CCIR 601). sieve . stats . sqrt sqrt(rand()) rand MWC . trig sin() x cos() + sin(2) + cos(3) float double long double = 0 2 . union union C. . zeta (s) s = 2.0..10.0 CPU . . . --cpu-old-metrics V0.14.02 CPU bogo-op CPU bogo-op bogo-op ( ) "all" . Intel i5-8350U bogo-ops bogo-op . . --cpu-ops N CPU N bogo. (CPU onlining stressor) --cpu-online N N . (root) . (CPU 0) (shutdown) . --cpu-online-affinity . --cpu-online-all . CPU 0 . . --cpu-online-ops N N / . (CPU affinity scheduler stressor) --cpu-sched N N CPU (scheduler) . 16 CPU SCHED_OTHER SCHED_BATCH SCHED_IDLE SCHED_EXT SCHED_DEADLINE SCHED_RR SCHED_FIFO . CPU 8 CPU . nice . --cpu-sched-ops N N . --cpu-sched-procs N . 2 1024 16 . (Cyclic Redundancy Check stressor) --crc N N CRC 1024 . __builtin_crc gcc CRC . CRC : crc8_data8 CRC 128 x 8 crc16_data8 CRC 128 x 8 crc16_data16 CRC 64 x 16 crc32_data8 CRC 128 x 8 crc32_data16 CRC 64 x 16 crc32_data32 CRC 32 x 32 crc64_data8 CRC 128 x 8 crc64_data16 CRC 64 x 16 crc64_data32 CRC 32 x 32 crc64_data64 CRC 16 x 64 --crc-ops N N x 64 CRC. (Crypt stressor) --crypt N N 16 crypt(3) . bcrypt bsdicrypt descrypt gost- yescrypt MD5 NT scrypt SHA-1 SHA-256 SHA-512 SunMD5 yescrypt . --crypt-method method : bcrypt bsdicrypt descrypt gost-yescrypt MD5 NT scrypt SHA-1 SHA-256 SHA-512 SunMD5 yescrypt. `all' . --crypt-ops N N bogo. (Complex trigonometric functions stressor) --ctrig N N sin cos tan libm complex float complex double complex long double . 10000 bogo-operation . --ctrig-method function . . : all ccos ( complex double) ccosf ( complex float) ccosl ( complex long double) csin ( complex double) csinf ( complex float) csinl ( complex long double) ctan ( complex double) ctanf ( complex float) ctanl ( complex long double) --ctrig-ops N N (bogo-operations) . Cyclic 5 --cyclic N N . . cyclic . (real time) CAP_SYS_NICE . FIFO . --cyclic-dist N N . . --cyclic-method [ clock_ns | itimer | poll | posix_ns | pselect | usleep ] (cyclic) clock_ns . : lB2 lB l lx. clock_ns nanosleep clock_nanosleep(2) CLOCK_REALTIME. itimer itimer CLOCK_REALTIME. poll poll clock_gettime(2) CLOCK_REALTIME . posix_ns nanosleep(2) POSIX . pselect pselect(2) (null). usleep usleep(2). --cyclic-ops N N . --cyclic-policy [ batch | deadline | ext | fifo | idle| other | rr ] batch deadline ext fifo ( ) idle other rr ( round-robin). --cyclic-prio P P. () (). --cyclic-samples N N . . --cyclic-sleep N N clock_nanosleep(2) CLOCK_REALTIME. . Daemon --daemon N N (daemon) . init . init (child reaping) . UNIX . --daemon-bloat N . ( ) 4K 64MB . --daemon-ops N N . --daemon-wait init. (fork) . (DCCP) --dccp N N (DCCP) (RFC4340) . / . --dccp-domain D (domain) ipv4 . ipv4 ipv6 . --dccp-if NAME NAME. NAME (up) loopback (lo) . --dccp-msgs N N / . . N dccp . --dccp-port P DCCP P. N dccp P P + (N-1) ( ). . --dccp-ops N dccp N (bogo operations). --dccp-opts [ send | sendmsg | sendmmsg ] send(2) . send(2) sendmsg(2) sendmmsg(2) . sendmmsg . Mutex Dekker --dekker N N (mutex exclusion) (Dekker Algorithm) . (memory fencing) GCC __sync_synchronize . mutex (memory coherency) . --dekker-ops N dekker N mutex. Dentry -D N, --dentry N N (dentry) . . gray-code (hashing) . --dentry-negative dentry dentry cache. --dentry-ops N dentry N dentry. --dentry-order [ forward | reverse | stride | random ] (unlink) dentry forward reverse stride random . dentry (random) . (forward) (reverse) (stride) (random) forward reverse stride . --dentries N N dentry dentry . dentry --dentrycache N N dentry cache dentry . 2^64 dentry . dentry cache --buddystat --vmstat . --dentrycache-method [ all | access | getxattr | lstat | open | readlink | stat | utime ] dentry 'all' ..TP --dentrycache-ops N N . /dev --dev N N /dev . open(2) fstat(2) lseek(2) poll(2) fcntl(2) mmap(2) munmap(2) fsync(2) close(2) . (watchdog) . --dev-alldev ( /dev/i2c-0) ( /dev/i2c-*) . --dev-file filename /dev/null. . --dev-ops N dev N (bogo op) . /dev/shm --dev-shm N N fallocate /dev/shm mmap (touch ). / (buffer cache) . . --dev-shm-ops N N (bogo op) mmap /dev/shm. --dfp N N . bogo op . --dfp-method method : all : df32add (_Decimal32) df64add (_Decimal64) df128add (_Decimal128) df32sub (_Decimal32) df64sub (_Decimal64) df128sub (_Decimal128) df32mul (_Decimal32) df64mul (_Decimal64) df128mul (_Decimal128) df32div (_Decimal32) df64div (_Decimal64) df128div (_Decimal128) . --dfp-ops N N (bogo op) . --dir N N mkdir(2) rename(2) rmdir(2) . --dir-dirs N N . . --dir-ops N (directory thrash) N (bogo op) . --dirdeep N N - (depth-first) PATH_MAX ENAMETOOLONG ( ) . --dirdeep-dir . (inode) (symlink) (hardlink) . --dirdeep-bytes N 0 . b k m g . --dirdeep-files . --dirdeep-dirs N N . . --dirdeep-files N N . 0 --dirdeep-bytes . --dirdeep-inodes N N dirdeep . N . --dirdeep-ops N N (bogo op) . --dirmany N N . ( quota ) . bogo-ops . dentry . --dirmany-bytes N 0 . b k m g . --dirmany-ops N dirmany N . dnotify --dnotify N N / / dnotify ( )..TP --dnotify-ops N dnotify N bogo dnotify. Dup --dup N N dup(2) close(2) /dev/zero . 65536 . --dup-ops N dup N bogo. --dynlib N N . . dlopen(3) . --dynlib-ops N N bogo /. --easy-opcode N N 64 (opcode) . x86 nop / . RISC nop / . ( move r0,r0) . --easy-opcode-ops N N 64 . Eigen ++C --eigen N N Eigen ++C long double double float . gcc/g++ . --eigen-method method : all Eigen add-longdouble long double add-double double add-float float determinant-longdouble long double determinant-double double determinant-float float inverse-longdouble long double inverse-double double inverse-float float multiply-longdouble long double multiply-double double multiply-float float transpose-longdouble long double transpose-double double transpose-float float --eigen-ops N N Eigen. --eigen-size N N x N. 32 x 32 . EFI --efivar N N EFI /sys/firmware/efi/efivars /sys/firmware/efi/vars . EFI CAP_SYS_ADMIN . --efivar-ops N efivar N EFI. (ENOSYS) --enosys N N . . ( ENOSYS ) . 0 __NR_syscalls + 1024 0 2^8 2^16 2^24 2^32 2^40 2^48 2^56 2^64 . . --enosys-ops N N bogo enosys. --env N N setenv(3) . ENOMEM . (OOM killer) . --env-ops N N bogo setenv/unsetenv. Epoll --epoll N N epoll_wait(2) . / / . epoll bogo op epoll . ipv4 ipv6 . epoll . --epoll-domain D unix ( local) . ipv4 ipv6 unix ..TP --epoll-ops N epoll N bogo. --epoll-port P P. N epoll P (P x 4) - 1 ipv4 ipv6 P P - 1 unix . (wrap ) . . --epoll-sockets N . (out of memory) . epoll --epollmany N N epoll_create1(2) epoll_ctl(2) . epoll pipe epoll epoll . epoll . --epollmany-delete epoll . epoll_ctl(2) EPOLL_CTL_DEL . --epollmany-fds epoll_create1(2) . . --epollmany-ops N N epoll_create1(2). --eth-sniff N N ethernet (sniff) . --metrics IPv4 IPv6 . CAP_NET_RAW . --eth-sniff-ops N N bogo ethernet. (eventfd) --eventfd N N eventfd ( ). --eventfd-nonblock EFD_NONBLOCK . EAGAIN I/O (polling) . --eventfd-ops N eventfd N bogo. Exec --exec N N fork stress-ng exec . pthread exec pthread exec (context) pthread . --exec-fork-method [ clone | fork | rfork | spawn | vfork ] clone(2) fork(2) BSD rfork(2) posix_spawn(3) vfork(2). vfork execve (exec) . --exec-max P P stress-ng exec . (zombie) (reaped) . --exec-max --exec . --exec-method [ all | execve | execveat | fexecve ] exec all execve(2) execveat(2) fexecve(3) execve execve(2) execveat execveat(2) ( ) fexecve fexecve(3) ( ) . --exec-no-pthread pthread_create(3). --exec-ops N exec N bogo. pthread --exit-group N N pthread pthread exit_group(2) ( ). --exit-group-ops N N pthread. --expmath N N (sanity check) . --expmath-ops N N bogo . --expmath-method method . : all cexp double cexpf float cexpl long double exp double expf float expl long double exp10 double exp10f float exp10l long double exp2 double exp2f float exp2l long double --factor N N (GNU Multiple Precision Arithmetic Library) () . N > 100 N 0.4 x N . . --factor-digits N . ..TP --factor-ops N N . (fallocate) -F N, --fallocate N N fallocate ( ) ftruncate ( ) . fallocate ENOSPC . --fallocate-bytes N 1 GB . b k m g . --fallocate-ops N fallocate N (bogo) fallocate. (fanotify) --fanotify N N (unlink) fanotify ( ). fanotify . CAP_SYS_ADMIN . --fanotify-ops N fanotify N fanotify. --far-branch N N . (1 op) . (memory-mapped) . . (instruction cache) TLB . --far-branch-flush (flush) (cache misses). --far-branch-ops N N (bogo-op) . . --far-branch-pageout (pageout) soft-offline . MADV_PAGEOUT MADV_SOFT_OFFLINE madvise(2) . --far-branch-pages N . x86 SPARC64 . (Page fault) --fault N N (minor) (major) . --fault-ops N N . fcntl --fcntl N N fcntl(2) . ( ) : F_CREATED_QUERY F_DUPFD F_DUPFD_CLOEXEC F_GETFD F_SETFD F_GETFL F_SETFL F_GETOWN F_SETOWN F_GETOWN_EX F_SETOWN_EX F_GETSIG F_SETSIG F_GETOWNER_UIDS F_GETLEASE F_GETLK F_SETLK F_SETLKW F_UNLCK F_OFD_GETLK F_OFD_SETLK F_OFD_SETLKW F_GET_FILE_RW_HINT F_SET_FILE_RW_HINT F_GET_RW_HINT F_SET_RW_HINT. --fcntl-ops N fcntl N fcntl. --fd-abuse N N (file dup socket pipe timerfd pidfd userfaultfd ) . . --fd-abuse-ops N N . --fd-fork N N dup(2) ( /dev/zero) (fork) clone_range(2) close(2) _exit(2) . , dup(2) . --fd-fork-fds N . . . --fd-fork-file [ null | random | stdin | stdout | zero ] dup: null /dev/null random /dev/random stdin stdout zero /dev/zero. /dev/zero . --fd-fork-ops N N dup // . bogo-ops fork close . (fd-race) --fd-race N N (race conditions) . . pthread pthread . pthread . open fd-race /dev /proc . --fd-race-dev /dev . --fd-race-race-ops N N . --fd-race-proc /proc . --fibsearch N N . bsearch . bsearch bsearch . . . --fibsearch-ops N fibsearch N . --fibsearch-size N ( ) fibsearch. 1 K 4 M . (fiemap) --fiemap N N (extent) ioctl(2) FS_IOC_FIEMAP . --fiemap-bytes N fiemap . b k m g . . --fiemap-ops N N (bogo operations) fiemap. FIFO --fifo N N (named pipe) . --fifo-data-size N / fifo .. . --fifo-ops N fifo N . --fifo-readers N N fifo . .. . / (ioctl) --file-ioctl N N ioctl(2) . ioctl FIONBIO FIOQSIZE FIGETBSZ FIOCLEX FIONCLEX FIONBIO FIOASYNC FIOQSIZE FIFREEZE FITHAW FICLONE FICLONERANGE FIONREAD FIONWRITE FS_IOC_RESVSP . --file-ioctl-ops N file-ioctl N ioctl . --filehole N N . FALLOC_FL_PUNCH_HOLE FALLOC_FL_ZERO_RANGE fallocate(2) . . fsync . (page size) . --filehole-bytes N filehole . b k m g . --filehole-defrag (naive) . --filehole-ops N filehole N write/fallocate. --filename N N . . --filename-ops N filename N . --filename-opts opt `opt'. : probe posix The Open Group Base Specifications Issue 7 POSIX.1-2008 3.278 Portable Filename Character Set ext ext2 ext3 ext4 NUL / utf8 utf8 urf8-like utf8 utf8 (filerace) --filerace N N . (race conditions) . . --filerace-procs N . . . --filerace-ops N N . --flipflop N N (threads) CPU (affine) . cmpxchg (/ compare/exchange) flip/flop 0 1 (flip) 1 0 (flop). (cacheline) flip/flop ( starvation ). --flipflop-bits N ( flip/flop) . --flipflop-taskset1 list CPU flip (affine) . list --taskset . --flipflop-taskset2 list CPU flop (affine) . list --taskset . --flipflop-ops N N (bogo- ops) bogo-op flip- flop . (flock) --flock N N . --flock-ops N flock N flock. --flushcache N N ( ) (flush) . no-op ( ) ..TP --flushcache-d-bytes N (data flush) 1K 4GB . b k m g . --flushcache-i-bytes N (instruction flush) 1K 4GB (level 1 instruction cache). b k m g . --flushcache-ops N N . / (fma) --fma N N . (Intel Haswell AMD Bulldozer Piledriver) C (opcodes) / (fma3) . : a = (a x b) + c a = (b x a) + c a = (b x c) + a a = (a x b) - c a = (b x a) - c a = (b x c) - a --fma-libc fma libc . FMA libc ( ) __builtin libc fma libc . / . --fma-ops N N bogo . (fork) -f N, --fork N N (fork) . --fork-max P P . (reap) . --fork-max --fork . --fork-ops N fork N bogo . --fork-pageout (page-out) fork . --fork-unmap (unmap) vma (anonymous vma) . (ugly hack) vma . . --fork-vm madvise(2) . MADV_MERGEABLE MADV_WILLNEED MADV_HUGEPAGE MADV_RANDOM madvise(2) . . (heavy fork) --forkheavy N N . fork . (reap) (FIFO) . --forkheavy-allocs N N . pipes pthreads ptys . (fork) . 16384 . --forkheavy-mlock mlock(2) . mlock(MCL_FUTURE) brk (swap out) . --forkheavy-ops N N fork . --forkheavy-procs N N . . (floating point) --fp N N . bogo . --fp-method method : all : float128add ibm128add IBM (powerpc) float80add float64add float32add binary32 floatadd bf16add bf16 doubleadd (double precision) ldoubleadd (long double precision) float128sub ibm128sub IBM (powerpc) float80sub float64sub float32sub binary32 floatsub bf16sub bf16 doublesub (double precision) ldoublesub (long double precision) float128mul ibm128mul IBM (powerpc) float80mul float64mul float32mul binary32 floatmul bf16mul bf16 doublemul (double precision) ldoublemul (long double precision) float128div ibm128div IBM (powerpc) float80div float64div float32div binary32 floatdiv bf16div bf16 doublediv (double precision) ldoublediv (long double precision) . --fp-ops N N (bogo ops) . bogo-ops float double long double . --fp-error N N . FE_DIVBYZERO FE_INEXACT FE_INVALID FE_OVERFLOW FE_UNDERFLOW . EDOM ERANGE . --fp-error-ops N N bogo. --fp-misc N N libm : fpclassify(3) isgreater(3) isgreaterequal(3) isless(3) islessequal(3) islessgreater(3) isunordered(3) isfinite(3) isnormal(3) isnan(3) isinf(3) signbit(3). float double long double (normal) (infinite) (nan) . --fp-misc-ops N N bogo . (subnormal) --fp-subnormal N N (subnormal) . bogo op . . C . --fp-subnormal-method method : all : floatadd doubleadd (double) ldoubleadd (long double) floatsub doublesub (double) ldoublesub (long double) floatmul doublemul (double) ldoublemul (long double) floatdiv doublediv (double) ldoublediv (long double) --fp-subnormal-ops N N bogo . (punch and hole fill) --fpunch N N . FALLOC_FL_KEEP_SIZE FALLOC_FL_PUNCH_HOLE FALLOC_FL_ZERO_RANGE FALLOC_FL_COLLAPSE_RANGE FALLOC_FL_INSERT_RANGE fallocate(2) extent . --fpunch-bytes N fpunch 16 MB . (%) b k m g . --fpunch-ops N fpunch N (bogo) . --fractal N N . (Mandelbrot) . N fractal . . (Naive) . --fractal-iterations N (quadratic map) . --fractal-method [ julia | mandelbrot ] (Julia set) (Mandelbrot set) . --fractal-ops N N . --fractal-sizex N . --fractal-sizey N . --fsize N N ( RLIMIT_FSIZE setrlimit(2)) . (truncate) SIGXFSZ . --fsize-ops N N bogo. (fstat) --fstat N N fstat ( /dev ). --fstat-dir directory fstat /dev. fstat . --fstat-ops N fstat N fstat (bogo). /dev/full --full N N /dev/full . ( ENOSPC ) ( ) (seek) ( ). ( )..TP --full-ops N full N bogo I/O. (Function argument passing) --funccall N N . --funccall-method . (registers) . --funccall-ops N funccall N bogo . bogo . --funccall-method method funccall . bool uint8 uint16 uint32 uint64 uint128 float double longdouble cfloat ( ) cdouble ( ) clongdouble ( ) float16 float32 float64 float80 float128 decimal32 decimal64 decimal128 . . (Function return) --funcret N N (by value) . --funcret-ops N funcret N bogo . --funcret-method method funcret . 'all' uint8 uint16 uint32 uint64 uint128 float double longdouble float80 float128 decimal32 decimal64 decimal128 uint8x32 uint8x128 uint64x128 cfloat cdouble clongdouble . (futex) --futex N N futex . : futex futex. futex . . --futex-ops N futex N bogo futex. (Gamma functions) --gamma N N tgamma lgamma libm float double long double . bogo . 0 t^(x - 1) e^-t dt . --gamma-method function . . : all lgamma (double) lgammaf (float) lgammal (long double) tgamma (double) tgammaf (float) tgammal (long double) --gamma-ops N N bogo. (Fetching data from kernel) --get N N : getpid(2) getppid(2) getcwd(3) getgid(2) getegid(2) getuid(2) getgroups(2) getpgrp(2) getpgid(2) getpriority(2) getresgid(2) getresuid(2) getrlimit(2) prlimit(2) getrusage(2) getsid(2) gettid(2) getcpu(2) gettimeofday(2) uname(2) adjtimex(2) sysfs(2). . --get-ops N get N bogo get. --get-slow-sync N get (locking contention) . N . (Linux) --getdent N N /proc /dev/ /tmp /sys /run getdents(2) getdents64(2) ( ). --getdent-ops N getdent N bogo getdent. (getrandom) --getrandom N N getrandom(2) () getentropy(2) () /dev/urandom . --getrandom-ops N getrandom N bogo get. (CPU pipeline and branch prediction) --goto N N bogo ( ) ( ) . . (pipelined) . --goto-direction [ forward | backward | random ] forward backward random . --goto-ops N goto N bogo . OpenGL (GPU) --gpu N N (GPU) . (2-D texture) (shaders) opengl . --gpu-devnode DEVNAME GPU /dev/dri/renderD128 . --gpu-frag N N (fragment shader) ..TP --gpu-ops N gpu N (render loop). --gpu-tex-size N (texture) N x N 4096 x 4096 . --gpu-xsize X (framebuffer) X . 256 . --gpu-ysize Y (framebuffer) Y . 256 . --gpu-upload N N 1 . Handle --handle N N name_to_handle_at(2) open_by_handle_at(2) ( ). --handle-ops N N (bogo) handle. (String hashing) --hash N N (hashing) . (chi squared) . (goodness-of-fit) (hash buckets) . 1.0 . --hash-method method . : all adler32 Mark Adler Fletcher coffin xor coffin32 xor crc32c CRC32C (Castagnoli CRC32) djb2a Dan Bernstein xor fnv1a FNV-1a Fowler-Noll-Vo xor jenkin Jenkin kandr Kernighan Richie "The C Programming Language" knuth Donald E. Knuth "The Art Of Computer Programming" . loselose Kernighan Richie "The C Programming Language" mid5 xor shift . Colin Ian King muladd32 xor muladd64 xor mulxror32 xor . . Colin Ian King mulxror64 xor . mulxror32 murmur3_32 Murmur3 Austin Appleby nhash nhash exim. pjw Peter J. Weinberger AT&T Bell Labs UNIX ELF sdbm sdbm SDBM GNU awk sedgwick C Robert Sedgwick sobel Justin Sobel x17 . xor xor xorror32 xor Colin Ian King xorror64 xorror32 xxhash << >> (Extremely fast) (non-streaming) --hash-ops N N (File-system) -d N, --hdd N N . . --aggressive --hdd-opts hdd --hdd-opt I/O . --hdd-bytes N N hdd 1 GB . (%) b k m g . --hdd-opts list . : direct (cache) I/O. I/O . I/O sync . dsync ( O_DSYNC). write(2) fdatasync(2) . fdatasync . fadv-dontneed . fadv-noreuse . fadv-normal . . fadv-rnd . fadv-seq . fadv-willneed . fsync (in-core) fsync(2). fdatasync fsync . fdatasync(2) . iovec I/O readv/writev read/write. read/write iovec . noatime . sync ( O_SYNC). write(2) fsync(2) . fsync . rd-rnd . rd-seq . syncfs hdd . utimes . wr-rnd . wr-seq . wr-seq . . ( ) . fadvise fadv-willneed fadv-dontneed . --hdd-ops N hdd N bogo. --hdd-sleep N ( ) N I/O (hdd). . 0..3600. --hdd-write-size N . 1 4 . BSD heapsort 5 --heapsort N N heapsort BSD . --heapsort-method [ heapsort-libc | heapsort-nonlibc ] libc heapsort heapsort. libc . --heapsort-ops N heapsort N bogo heapsort. --heapsort-size N 262144 (256 x 1024) . (High resolution timer) 5 --hrtimers N N (hrtimer) . 0..499999 . SCHED_RR . --hrtimers-adjust hrtimer. 0.1 hrtimer . --hrtimers-ops N hrtimers N bogo . (hsearch) 5 --hsearch N N (hash table) hsearch(3) . . () . --hsearch-method [ hsearch-libc | hsearch-nonlibc ] libc hsearch non-libc hsearch. libc non-libc. --hsearch-ops N hsearch N bogo hsearch. --hsearch-size N . 1 K 4 M . Huge page 5 --hugepage N N (collapsing) huge page ( ) . huge page (page table locking) TLB shootdown . huge page huge page . --hugepage-dontneed MADV_DONTNEED huge page. (zeroing) . --hugepage-method [ forward | random | reverse ] hugepage forward random reverse . random . --hugepage-num N N (huge page) . . --hugepage-ops N . --hugepage-remove MADV_REMOVE huge page. (zeroing) . (Hyperbolic functions) 5 --hyperbolic N N libm sinh cosh tanh float double long double . , bogo-operation . --hyperbolic-method function . . : lB2 lB l lx. all cosh ( double) coshf ( float) coshl ( long double) sinh ( double) sinhf ( float) sinhl ( long double) tanh ( double) tanhf ( float) tanhl ( long double) --hyperbolic-ops N N bogo. (CPU instruction cache) --icache N N instruction cache . --icache-ops N icache N bogo icache. --icache-pages N . . ICMP (ICMP flood) --icmp-flood N N (localhost) ICMP (flood) . CAP_NET_RAW . --icmp-flood-max-size ..TP --icmp-flood-ops N icmp N ICMP. () --idle-page N N /sys/kernel/mm/page_idle/bitmap . CAP_SYS_RESOURCE . --idle-page-ops N N (bogo) . ioctl --inode-flags N N inode ioctl(2) FS_IOC_GETFLAGS FS_IOC_SETFLAGS inode file_getattr(2) file_getatt(2) . inode ( ). (thread) (race) . ioctl_iflags(2) . --inode-flags-ops N inode-flags N ioctl. Inotify --inotify N N / inotify ( ). --inotify-ops N inotify N (bogo) inotify. --insertionsort N N . --insertionsort-ops N insertionsort N (bogo). --insertionsort-size N (16 x 1024) . --intmath N N (modulo) . --intmath-fast int_fast64_t int_fast32_t int_fast16_t int_fast8_t int64_t int32_t int16_t int8_t. . --intmath-method method : all : add128 add64 add32 add16 add8 sub128 sub64 sub32 sub16 sub8 mul128 mul64 mul32 mul16 mul8 div128 div64 div32 div16 div8 mod128 (modulo) mod64 (modulo) mod32 (modulo) mod16 (modulo) mod8 (modulo) --intmath-fast : all : addfast64 addfast32 addfast16 addfast8 subfast64 subfast32 subfast16 subfast8 mulfast64 mulfast32 mulfast16 mulfast8 divfast64 divfast32 divfast16 divfast8 modfast64 (modulo) modfast32 (modulo) modfast16 (modulo) modfast8 (modulo) --intmath-ops N intmath N (bogo) . (sync) 5 -i N, --io N N sync(2) (buffer cache) . --hdd . (legacy) stress . --io-ops N io N (bogo). I/O 5 --iomix N N / (memory-mapped) / ( /root) (cache dropping) . I/O . --iomix-bytes N N iomix 1 GB . (%) Bytes KBytes MBytes GBytes b k m g . --iomix-ops N iomix N (bogo) I/O iomix. I/O ( x86) 5 --ioport N N ioport 0x80 ( x86). I/O x86 0x80 CPU I/O . --ioport-ops N ioport N (bogo) I/O. --ioport-opts [ in | out | inout ] io . in out . (in) (out) . --ioport-port [ post | vga-dac-r | bochs-debug ] I/O x86 : post ( /Power-On-Self-Test 0x80) vga-dac-r ( VGA DAC 0x3c8) bochs-debug ( Bochs 0xe9). I/O 5 --ioprio N N ioprio_get(2) ioprio_set(2) ( ). --ioprio-ops N N (bogo) io. Io-uring 5 --io-uring N N io-uring io-uring . --io-uring-entries N io-uring. --io-uring-ops N N io-uring. --io-uring-rand io-uring (file seek). IPsec 5 --ipsec-mb N N Intel Multi-Buffer Crypto for IPsec . SSE AVX AVX AVX512 SHA DES CMAC CTR HMAC MD5 HMAC SHA1 HMAC SHA512 . x86-64 . --ipsec-mb-feature [ sse | avx2 | avx512 | noaesni ] . CPU . --ipsec-mb-jobs N N (multi-block) . . --ipsec-mb-method [ all | cmac | ctr | des | hmac-md5 | hmac-sha1 | hmac-sha512 | sha ] / ipsec-mb. --ipsec-mb-ops N N . (System interval timer) 5 --itimer N N . itimer ITIMER_PROF SIGPROF . itimer 1 MHz jiffy SIGPROF . (busy loop) getitimer(2) CPU itimer CPU . --itimer-freq F itimer F 1 1000000 . jiffy 1000 . --itimer-ops N itimer N (bogo) SIGPROF itimer. --itimer-rand +-12.5% (jitter) . . Jpeg 5 --jpeg N N jpeg (plasma field) . . . --jpeg-height H H RGB. 512 . --jpeg-image [ brown | flat | gradient | noise | plasma | xstripes ] . : lB2 lB l lx. brown . flat . gradient . noise . plasma . xstripes . --jpeg-ops N N jpeg. --jpeg-quality Q Q. .. ( ) ..TP --jpeg-width H RGB H . . Judy --judy N N (sparse) Judy . Judy . . --judy-ops N judy N (bogo) judy. --judy-size N ( ) Judy . 1 K 4 M . Kcmp () --kcmp N N kcmp(2) . CAP_SYS_PTRACE . --kcmp-ops N kcmp N (bogo) kcmp. --key N N add_key(2) ketctl(2) . keyctl : KEYCTL_SET_TIMEOUT KEYCTL_DESCRIBE KEYCTL_UPDATE KEYCTL_READ KEYCTL_CLEAR KEYCTL_INVALIDATE. --key-ops N key N (bogo) . --kill N N SIGUSR1 kill(2) SIG_IGN SIGUSR1 SIGUSR1 . . --kill-ops N kill N (bogo) kill. Syslog () --klog N N syslog(2) . . . --klog-ops N klog N syslog. KVM --kvm N N 64 bit ARM RISC-V x86 ARM. x86 (spin loop) 0x80 I/O . ARM64 RISC-V MMIO MMIO . --kvm-ops N kvm N . (L1) --l1cache N N . (cache aligned) . (cache block evictions) . bogo-op . . : --l1cache-line-size N ( ) --l1cache-method [ forward | random | reverse ] l1cache. forward scan ( ) random pick ( ) reverse ( ). forward scan . --l1cache-mlock l1cache mlock(2) (swap out) . --l1cache-ops N bogo-op / --l1cache-sets N --l1cache-size N ( ) --l1cache-ways N (ways) Landlock ( >= 5.13) --landlock N N (landlocking) 5.13 . landlock_create_ruleset(2) - - . . --landlock-ops N landlock N (bogo) landlock. --lease N N F_SETLEASE fcntl(2) (break) . ( ) (non-blocking) SIGIO . F_SETLEASE F_WRLCK F_UNLCK fcntl(2) . --lease-breakers N N lease. SIGIO . --lease-ops N lease N (bogo). LED () --led N N /sys/class/leds LED (trigger) . (root) . . --led-ops N N . --link N N (hardlinks). --link-ops N link N (bogo). --link-sync (dirty) . (List data structures stressor) --list N N . circleq ( ) list ( ) slist ( ) slistt ( ) stailq ( ) tailq ( ) . . --list-method [ all | circleq | list | slist | stailq | tailq ] . ( "all"). --list-ops N N bogo. bogo () . --list-size N N . (Last level of cache stressor) --llc-affinity N N (LLC) / LLC (CPU affinity) / . / (misses) LLC . --llc-affinity-clflush (cachelines) x86 ppc64. --llc-affinity-mlock LLC mlock(2) (swap). --llc-affinity-numa NUMA . NUMA . --llc-affinity-ops N N / LLC. --llc-affinity-size N LLC N . b k m g . (Load average stressor) --loadavg N N pthread nice (load average) . I/O I/O . --loadavg-max N pthreads N. pthreads N . --loadavg-ops N loadavg N (bogo scheduling yields) pthreads. x86 ARM --lockbus N N mmap ( Intel x86 ARM). mmap lockbus lockbus . (cacheline misses) . NUMA NUMA NUMA . --lockbus-bytes N N . b k m g . --lockbus-nosplit (split locks) . --lockbus-ops N lockbus N bogo. POSIX F_SETLK/F_GETLK --locka N N POSIX ( fcntl(2) F_SETLK F_GETLK) . . (FIFO) . --locka-ops N locka N bogo locka. POSIX lockf --lockf N N POSIX lockf(3) . . (FIFO) . --lockf-nonblock F_LOCK lockf(3) F_TLOCK . lockf . --lockf-ops N lockf N bogo lockf. (locka lockf lockofd) --lockmix N N BSD flock(2) locka () POSIX lockf(3) (lockofd) . . (FIFO) . --lockmix-ops N lockmix N bogo lockmix. (ofd F_OFD_SETLK/F_OFD_GETLK) --lockofd N N ( fcntl(2) F_OFD_SETLK F_OFD_GETLK) . . (FIFO) . --lockofd-ops N lockofd N bogo lockofd. --logmath N N libm . (sanity check) . --logmath-ops N N (logarithmic bogo- operation loops). --logmath-method method . : all clog double clogf float clogl long double log double logf float logl long double logb double logbf float logbl long double log10 double log10f float log10l long double log2 double log2f float log2l long double (longjmp) --longjmp N N longjmp setjmp(3)/longjmp(3) . --longjmp-ops N longjmp N bogo longjmp ( bogo longjmp ). (Loopback) () --loop N N loopback . loopback 2 MB loopback . CAP_SYS_ADMIN . --loop-bytes N loop 1MB 1GB 2MB . --loop-ops N N bogo / loopback. (Linear search) --lsearch N N lsearch(3) . . . --lsearch-method [ lsearch-libc | lsearch-nonlibc | lsearch-sentinel ] libc lsearch libc lsearch lsearch (sentinel) . libc non-libc . --lsearch-ops N lsearch N bogo . --lsearch-size N ( ) lsearch. 1 K 4 M . (LSM) --lsm N N LSM lsm_list_modules(2) lsm_get_self_attr(2) ( ). bogo-op LSM LSM . --lsm-ops N N LSM. Madvise --madvise N N madvise(2) 4 MB . --madvise-bytes N (mmap) N madvise . 4K 64M 4 MB . b k m g . --madvise-hwpoison MADV_HWPOISON ( ). . --madvise-ops N madvise N bogo madvise. (Memory allocation) --malloc N N malloc(3) calloc(3) realloc(3) posix_memalign(3) aligned_alloc(3) memalign(3) free(3) . --malloc-max . ( malloc calloc realloc posix_memalign aligned_alloc memalign) . --malloc-bytes 64 K . (OOM killer) . --malloc-bytes N . N . b k m g . (heap) brk(2) mmap(2) . --malloc-max N . . / . --malloc-mlock mlock(2) (swap). --malloc-ops N N bogo malloc. bogo malloc(3) calloc(3) realloc(3) posix_memalign(3) aligned_alloc(3) memalign(3) . --malloc-pthreads N pthread malloc. 0 ( pthread). pthread . --malloc-thresh N malloc sbrk(2) mmap(2) . mallopt(3) GNU C . --malloc-touch ( ) . . malloc madvise mincore . --malloc-trim heap . . libc malloc malloc_trim(3) . --malloc-zerofree (free). . . (2D Matrix) --matrix N N . x86 (CPU) . x . --matrix-method . --matrix-method method . : all add N x N copy N x N div N x N frobenius N x N hadamard N x N identity N x N mean N x N mult N x N negate () N x N prod N x N sub N x N N x N square N x N trans N x N zero N x N --matrix-ops N N bogo. --matrix-size N N x N . (floating point) (cache) / . --matrix-yx y x x y. (data cache stalls) . (3D Matrix stressor) --matrix-3d N N . x86 (CPU) . x x . --matrix-3d-method . --matrix-3d-method method . : all add N x N x N copy N x N x N div N x N x N () frobenius (Frobenius) N x N x N hadamard (Hadamard) N x N x N identity N x N x N mean N x N x N mult N x N x N () negate N x N x N sub N x N x N N x N x N trans N x N x N zero N x N x N --matrix-3d-ops N N bogo. --matrix-3d-size N N x N x N . / . --matrix-3d-zyx z y x x y z. (data cache stalls) . (Memory contention stressor) --mcontend N N / (memory contention) . (thread) . . (CPU affinity) . --mcontend-numa NUMA . NUMA . --mcontend-ops N mcontend N / bogo. (Memory barrier stressor - ) --membarrier N N membarrier(2) ( ). --membarrier-ops N membarrier N bogo membarrier. (memcpy) --memcpy N N memcpy(3) memmove(3) (alignment) . . --memcpy-method [ all | libc | builtin | naive | naive_o0 .. naive_o3 ] memcpy. memcpy : all libc builtin naive libc memcpy memmove libc builtin (built-in) memcpy memmove naive (naive) naive_o0 naive_o1 -O1 naive_o2 -O2 CPU naive_o3 -O3 CPU --memcpy-ops N memcpy N bogo memcpy. (memfd stressor) --memfd N N memfd_create(2) ftruncate(2) mmap(2) ( ). --memfd-bytes N N memfd . Bytes KBytes MBytes GBytes b k m g ..TP --memfd-fds N N memfd 256 . 8 4096 memfd . --memfd-madvise madvise memfd (VM). --memfd-mlock mmap mlock(2) Swap . --memfd-numa NUMA . NUMA . --memfd-ops N N (bogo ops) memfd-create(2). --memfd-zap-pte (PTE) 5abfd71d936a8aefd9f9ccd299dea7a164a5d455 "mm: don't skip swap entry even if zap_details specified" . (opt-in) memfd . (Memory hotplug) ( ) --memhotplug N N (memory hotplug) . CAP_SYS_ADMIN . --memhotplug-mmap 1 K 1 MB . --memhotplug-ops N memhotplug N . / (Memory read/write) --memrate N N 1024 512 256 128 64 32 16 8 . 1024 512 256 . x86-64 ( "nt") 128 64 32 . x86-64 64 32 16 8 . (prefetching) 64 ("pf") . . . --memrate-bytes N . 256 MB . b k m g L1 L2 L3 LLC ( ) . --memrate-discontiguous mmap "" . --memrate-flush (flush) . --memrate-method memrate . memrate : all memrate read128nt 128 (non-temporal load) read128pf 128 (prefetching) read64pf 64 (prefetching) read1024 1024 read512 512 read256 256 read128 128 read64 64 read32 32 read16 16 read8 8 write64stoq 64 x86 rep stoq write32stow 32 x86 rep stow write16stod 16 x86 rep stod write8stob 8 x86 rep stob write64ds 64 x86 movdiri write128nt 128 (non-temporal store) write64nt 64 (non-temporal store) write32nt 32 (non-temporal store) write1024 1024 write512 512 write256 256 write128 128 write64 64 write32 32 write16 16 write8 8 memset memset libc --memrate-ops N N (bogo ops) memrate. --memrate-rd-mbs N MB/sec. (scheduling jitter) . . --memrate-wr-mbs N MB/sec. (scheduling jitter) . . (Memory thrash stressor) --memthrash N N (thermal overrun) . (thread) . CPU . N (CPUs) . --memthrash-method method memthrash. memthrash : all memthrash chunk1 memset chunk8 memset chunk64 memset chunk256 memset chunkpage memset (page size) copy128 N + 1 N . copy128nt N + 1 N (non-temporal) . flip () flush (cache line flush) lock ( Intel x86 ARM) matrix 2 x 2 memmove memset memset memset64 (non-temporal) memsetstosd rep stosd x86 ( x86) mfence (write serialization) numa (memory bind) numa prefetch random memthrash `random` `all` reverse spinread (spin loop) 2^19 spinwrite (spin loop) 2^19 swap swap64 swapfwdrev . tlb (cache line) (TLB). --memthrash-ops N N (bogo operations) memthrash. BSD (BSD mergesort stressor) --mergesort N N mergesort(3) . --mergesort-method [ mergesort-libc | mergesort-nonlibc ] libc mergesort mergesort. libc . --mergesort-ops N mergesort N (bogo mergesorts). --mergesort-size N 262144 (256 x 1024) . (File metadata mix) --metamix N N . open lseek write fdatasync close fsync stat open lseek (reads) close unlink lstat . --metamix-bytes N metamix . (%) b k m g . --metamix-ops N metamix N metafile. (Resident memory - mincore) --mincore N N mincore(2) . (unmap) mincore(2) . --mincore-ops N N mincore. mincore mincore(2) . --mincore-random . mincore . nanosleep (Minimum sleep time in nanosleep stressor) --min-nanosleep N M . min- nanosleep . --min-nanosleep-ops N N . --min-nanosleep-max N nanosleep . 10000 8192 . --min-nanosleep-sched [ batch | deadline | ext | fifo | idle | other | rr ] . deadline fifo rr (root) . / (Misaligned read/write stressor) --misaligned N N (misaligned) . 128 8 x 16 4 x 32 2 x 64 1 x 128 (cache boundary) . 1 . SIGBUS SIGILL SIGSEGV . --misaligned-method method : all int16rd 8 x 16 int16wr 8 x 16 int16inc 8 x 16 int16atomic 8 x 16 int32rd 4 x 32 int32wr 4 x 32 int32wtnt (non-temporal) 4 x 32 ( x86) int32inc 4 x 32 int32atomic 4 x 32 int64rd 2 x 64 int64wr 2 x 64 int64wrds (direct stores) 4 x 64 ( x86) int64wtnt (non-temporal) 4 x 64 ( x86) int64inc 2 x 64 int64atomic 2 x 64 int128rd 1 x 128 int128wr 1 x 128 int128inc 1 x 128 int128atomic 1 x 128 ( / 128 ) . --misaligned-ops N N (bogo op) . 65536 x 128 . Mknod/unlink (Mknod/unlink stressor) --mknod N N mknod(2) unlink(2) fifo (named sockets) . --mknod-ops N (directory thrash) N mknod. / (Memory mapped pages lock/unlock stressor) --mlock N N mlock(2) munlock(2) mlockall(2) munlockall(2) . . mlock 262144 . (mlock) 262144 (munlock) . --mlock-ops N N mlock. / (Many child memory mapped page lock/unlock process stressor) --mlockmany N N 1024 (child process) (fork) mmap(2) mlock(2) . swap ( ) ( ). (in-core) (kill) . --mlockmany-ops N N mlockmany ( mmap mlock). --mlockmany-procs N . 1024 . N . (mmap/munmap stressor) --mmap N N mmap(2)/munmap(2) . ( --mmap-bytes ) 4 4 4 . swap OOM killer . MAP_POPULATE . --mmap-file --mmap-async . 0.17.05 stress-ng --mmap-madvise --mmap-mergeable --mmap-mprotect --mmap-slow-munmap --mmap-write-check mmap 0.17.05 . --mmap-async msync --mmap-file . --mmap-bytes N N mmap 256 (256 MB) . (%) b k m g . --mmap-file msync . --mmap-madvise madvise(2) . --mmap-mergeable (mergeable) madvise(2) ..TP --mmap-mlock mmap mlock(2) swap . --mmap-mmap2 mmap2 4 K mmap2(2) mmap . --mmap-mprotect (protection) . (remap) - - - - . --mmap-numa NUMA . NUMA . --mmap-odirect I/O O_DIRECT . --mmap-ops N mmap N bogo. --mmap-osync I/O O_SYNC . --mmap-slow-munmap (unmap) . mmap (lock contention) . --mmap-stressful --mmap-file --mmap-madvise --mmap-mergeable --mmap-mlock --mmap-mprotect --mmap-odirect --mmap-slow-munmap . --mmap-write-check (sanity check). (fault-in) bogo-op mmap . cgroup . / (Random memory map/unmap stressor) --mmapaddr N N . . . mmap/munmap mincore segfault . --mmapaddr-mlock mmap mlock(2) swap . --mmapaddr-ops N N bogo mmap . -- (Memory map Copy-on-Write and unmap stressor) --mmapcow N N ( Copy-on-Write) . . (cache) (flush) . (page fault) . : ( ) (prime) ( ) --mmapcow-fork fork . --mmapcow-free madvise(2) MADV_FREE ( ) . --mmapcow-mlock mlock(2) (page faults) . mlock2 . --mmapcow-numa NUMA . NUMA . --mmapcow-ops N N . (Forked memory map stressor) --mmapfork N N (fork) ( ). madvise(2) (hint) memset madvise . (VM) (cache misses) . --mmapfork-bytes N fork . b k m g . --mmapfork-ops N N bogo mmapfork. --mmapfork-procs N (fork) . . (Memory map files stressor) --mmapfiles N N x . /lib /lib32 /lib64 /boot /bin /etc /sbin /usr /var /sys /proc . bogo-ops . --mmapfiles-numa NUMA . NUMA . --mmapfiles-ops N N / . --mmapfiles-populate (fault) . MAP_POPULATE (fault- in) . --mmapfiles-shared (shared memory mappings) . (Fixed address memory map stressor) --mmapfixed N N 128 K . mmap MAP_SHARED/MAP_PRIVATE MAP_LOCKED MAP_NORESERVE MAP_POPULATE . (remap) . madvise . --mmapfixed-mlock mmap mlock(2) swap . --mmapfixed-numa NUMA . NUMA . --mmapfixed-ops N N bogo mmapfixed. (Huge page) --mmaphuge N N (huge pages) mmap . MADV_NOHUGEPAGE MADV_HUGEPAGE madvise / (touch) . unmap unmap ( ). swap . --mmaphuge-file mmap . (anonymous) . --mmaphuge-mlock mmap mlock(2) swap . --mmaphuge-mmaps N . . --mmaphuge-numa NUMA. NUMA . --mmaphuge-ops N N (bogo operations) mmaphuge. --mmapmany N N . unmap . . --mmapmany-mlock mmap mlock(2) swap . --mmapmany-numa NUMA. NUMA . --mmapmany-ops N N (bogo operations) mmapmany. --mmaprandom N N . (anonymous) ( memfd) . mmap(2) ( ) munmap(2) mlock(2) munlock(2) madvise(2) posix_madvise(3) mincore(2) mremap(2) msync(2) mprotect(2) remap_file_pages(2) (cache flushing) . ( ) . . --mmaprandom-ops N N (bogo operations) . bogo-op ( // ). --mmaprandom-mappings N . --mmaprandom-maxpages N . maxpages . --mmaprandom-numa NUMA. NUMA . (Memory map torture) --mmaptorture N N . madvise(2) mremap(2) mprotect(2) msync(2) mlock(2) munlock(2) mseal(2) mincore(2) (truncation) (hole punching) . (sync) . NUMA NUMA . (cache misses) TLB IPI . --mmaptorture-bytes N N mmaptorture . b k m g . --mmaptorture-msync N msync msync . . msync . --mmaptorture-ops N N . () --module N N finit_module() hello ( ) . : modprobe module stress-ng. modprobe modprobe . tools/testing/selftests/kmod/kmod.sh . modprobe . modprobe . module stress-ng finit_module() (race conditions) . --module-name NAME (NAME) : test_module xfs ext4. test_module CONFIG_TEST_LKM . finit_module() modprobe . --module-no-modver modversions finit_module(). --module-no-vermag finit_module(). --module-no-unload finit_module(). --module-ops N N / . e --monte-carlo N N e ( ) . --monte-carlo-method [ all | e | exp | pi | sin | sqrt | squircle ] : all e e exp exp(x ^ 2) x = 0..1 pi sin sin(x) x = 0.. sqrt sqrt(1 + x ^ 4) x = 0..1 squircle (squircle) x ^ 4 + y ^ 4 = 1 --monte-carlo-ops N N (Monte Carlo). --monte-carlo-rand [ all | drand48 | getrandom | lcg | pcg32 | mwc64 | random | xorshift ] : lB2 lB l lx. all . arc4 arc4random(3) libc. drand48 drand48(3) libc . getrandom getrandom(2) . lcg - (Park-Miller) . pcg32 (O'Neill). mwc64 (Multiply With Carry) stress-ng. random random(3) libc. xorshift (Marsaglia). --monte-carlo-samples N e 100000 . (mpfr) --mpfr N N GNU Multi-Precision Floating Point Reliable (mpfr) . : apery (Apery) (3) 1/(n ^ 3). cosine cos() = 0 2 . euler e n = (1 + (1 / n)) ^ n. exp . log . omega e^ = 1 n+1 = (1 + n) / (1 + e^n). phi . sine sin() = 0 2 . nsqrt - (Newton-Raphson). --mpfr-ops N N . --mpfr-precision N () . 1000 32 1000000 ( ). (Memory protection) --mprotect N N . TLB (TLB flushes) . (segmentation fault) . . --mprotect-ops N N mprotect. POSIX () --mq N N POSIX . ( ). --mq-ops N N (bogo) POSIX. --mq-size N POSIX. 10 . . () --mremap N N mmap(2) mremap(2) munmap(2) . ( --mremap-bytes ) . . --mremap-bytes N N 256 MB . b k m g . --mremap-mlock (mlock(2)) (swap) . --mremap-numa NUMA . NUMA . --mremap-ops N mremap N (bogo). (Memory Sealing) --mseal N N madvise(2) mremap(2) mprotect(2) mseal(2) . 6.10 . --mseal-ops N N mseal. IPC System V --msg N N IPC System V . --msg-bytes N . 4 8192 4 . --msg-ops N N (bogo) . --msg-types N (mtype) . msgsnd mtype 1 1..N . (throughput) . (msync) --msync N N msync msync . MS_SYNC MS_INVALIDATE msync(2) . --msync-bytes N N (256 MB) . (%) b k m g . --msync-ops N N (bogo ops) msync. (msync) --msyncmany N N msync . msync . --msyncmany-ops N N msync msyncmany. mtx (mutex) ISO C --mtx N N mutex ISO C . --mtx-ops N N (bogo) / mutex. --mtx-procs N (thread) / mutex . . () --munmap N N (unmapping) ( ). . . (segmentation fault) _exit(2) . --munmap-ops N N . Pthread mutex --mutex N N pthread mutex . FIFO FIFO . FIFO mutex (random inverted priority scheduling) . --mutex-affinity (CPU affinity) mutex. --mutex-ops N N (bogo) / mutex. --mutex-procs N / mutex . . nanosleep --nanosleep N N (worker) pthreads nanosleep(2) 2^18 . . --nanosleep-method [ all | cstate | random | ns | us | ms ] nanosleep. cstate ( ) . : all cstate . cstate cstate. --nanosleep-threads 1 nanosleep C (C-states) . random 2^18 . ns nanosleep (1ns) us nanosleep (1s) ms nanosleep (1ms) --nanosleep-ops N nanosleep N (bogo) nanosleep. --nanosleep-threads N pthread . . ioctl --netdev N N ioctl(2) netdevice . ioctl : SIOCGIFCONF SIOCGIFINDEX SIOCGIFNAME SIOCGIFFLAGS SIOCGIFADDR SIOCGIFNETMASK SIOCGIFMETRIC SIOCGIFMTU SIOCGIFHWADDR SIOCGIFMAP SIOCGIFTXQLEN. ioctl netdevice(7) . --netdev-ops N N (bogo) netdev. proc Netlink () --netlink-proc N N fork/exec/exit proc netlink connector . (bogo op) . CAP_NET_ADMIN . --netlink-proc-ops N proc netlink connector N . task Netlink () --netlink-task N N taskstats netlink . CAP_NET_ADMIN . --netlink-task-ops N taskstats netlink connector N . Nice --nice N N nice . (fork) nice (busy loop) . --nice-ops N N nice. (NO-OP) --nop N N no-op . "nop" ..TP --nop-instr INSTR nop INSTR. x86 INSTR nop pause nop2 ( nop ) nop15 ( nop ) fnop . ARM INSTR nop yield . PPC64 INSTR nop mdoio mdoom yield . S390 INSTR nop nopr . INSTR nop . random INSTR nop . INSTR SIGILL (vanilla) nop . --nop-ops N nop N bogo (no-op). bogo no-op . /dev/null --null N N /dev/null write(2) lseek(2) ioctl(2) fcntl(2) fallocate(2) fdatasync(2) . /dev/null --null-write . --null-ops N null N bogo /dev/null. --null-write /dev/null (4 K) /dev/null. NUMA --numa N N NUMA (migrate) . migrate_pages(2) mbind(2) move_pages(2) . (cache miss) . NUMA . --numa-bytes N . . Bytes KBytes MBytes GBytes b k m g . --numa-ops N NUMA N bogo NUMA. --numa-shuffle-addr (shuffle) move_pages(2). --numa-shuffle-node (shuffle) move_pages(2). NUMA --numacopy N N NUMA NUMA . . . NUMA . --numacopy-affinity [ next | none | node | prev | random ] (CPU affinity) NODE . . : next CPU NUMA . CPU . none ( ) node CPU NODE . prev CPU NUMA . CPU . random CPU . --numacopy-mode [ bind | interleave | preferred | weighted-interleave ] mbind mbind(2) . --numacopy-ops N N bogo NUMA. bogo / . --oom-pipe N N (pipe) . . --aggressive (OOM) . OOM . --oom-pipe-ops N N bogo / . --opcode N N fork . (illegal instructions) (bus errors) (segmentation faults) (traps) (floating point errors) . --opcode-method [ inc | mixed | random | text ] opcode. . : inc opcode 0x00000000 0xfffffff . mixed opcode opcode gray . random opcode mwc. text text stress-ng / . --opcode-ops N N . (open) -o N, --open N N open(2) close(2) /dev/zero . ( ) . --open-fd /proc/$PID/fd . (racing) open/close proc . --open-max N N ( ). . --open-ops N open N bogo . OpenVPN DCO () --ovpn N N (ovpn) netlink . ovpn netlink : new peer set peer get peer delete peer new key delete key get key swap keys connect. getrandom(2) . bogo op . ovpn libnl-3 CAP_NET_ADMIN . --ovpn-ops N ovpn N bogo op. --ovpn-tunnel (fuzzing) DCO . (network namespace) veth ( UDP TCP IPv4 IPv6 ) ovpn . ( ) ( [peers] ) . "MB per sec encrypted, UDP transport, IPv4" peer ( ) . ovpn CAP_SYS_ADMIN CAP_NET_ADMIN . TLB --pagemove N N ( ) mmap (shuffle) . mremap . (TLB) . --pagemove-bytes N . b k m g . --pagemove-mlock mmap mremap mlock(2) swap . --pagemove-numa NUMA . NUMA . --pagemove-ops N N pagemove mmap (bogo-operation) . --pagescatter N N . MAP_FIXED_NOREPLACE MAP_FIXED mmap(2) (hinted) . mprotect(2) PROT_NONE (unmap) . (TLB) . . --pagescatter-numa NUMA (round-robin). NUMA . --pagescatter-ops N N (bogo ops) mmap. --pagescatter-order N 2^N . pagescatter . --pagescatter-populate -- (copy-on-write) . (Swap) --pageswap N N (swap in swap out) . MADV_PAGEOUT madvise(2) swap . mmap (page in) (unmap) . --pageswap-ops N N (bogo ops) . --pageswap-pages N mmap . . PCI sysfs () --pci N PCI sysfs N ( PCI PCI mmap/unmap ). . (root) mmap / (I/O) PCI . --pci-dev xxxx:xx:xx.x PCI PCI. PCI xxxx:xx:xx.x x . --pci-ops N pci N PCI. --pci-ops-rate N bogo-ops PCI. PCI x86 uncore . (Personality) --personality N N ( ) personality(2) . ( ). --personality-ops N personality N personality. --peterson N N (mutex) . (memory fencing) __sync_synchronize GCC . mutex (memory coherency) . --peterson-ops N peterson N mutex. mmap (Physpage) --physpage N N /proc/self/pagemap /proc/kpagecount (page count) . CAP_SYS_ADMIN . --physpage-mtrr (MTRR) ( x86). --physpage-ops N physpage N (bogo physical address lookups). mmap ( /dev/mem) --physmmap N N /dev/mem System RAM ( /proc/iomem ) mmap . CAP_SYS_ADMIN /proc/iomem mmap /dev/mem . (locked down) mmap /dev/mem . --physmmap-ops N physmmap N bogo mmap. --physmmap-read mmap . (pidfd_send_signal) --pidfd N N pidfd_send_signal(2) . pidfd_send_signal(2) . --pidfd-ops N pidfd N pidfd_send_signal (kill) . ICMP (ping) --ping-sock N N ICMP <> AF_INET SOCK_DGRAM IPPROTO_ICMP localhost (1024..65535) . --ping-sock-ops N ping-sock N ICMP. --ping-sock-max-size N . (Large pipe) -p N, --pipe N N / (I/O) . (context switching) . . --pipe-data-size N ( ). . . --pipe-ops N pipe N bogo . --pipe-readers N . --pipe-size N ( F_SETPIPE_SZ fcntl() ). . 0.15.11 . --pipe-writers N . --pipe-vmsplice vmsplice(2) (splice) / . O_DIRECT . (Shared pipe) --pipeherd N N / . << >> (thundering herd) . --pipeherd-ops N pipe N bogo . --pipeherd-procs N . . --pipeherd-yield (yield) . () --pkey N N pkey(2) pkey_mprotect(2) ( ). pkey pkey -1 ( mprotect ). read/write/exec/none . --pkey-ops N N pkey_mprotect. (plugin) stress-ng --plugin N N . stress_ . stress_ (round-robin) --plugin-method . 0 ( plugin ). bogo-op . nop bogo-op : int stress_example(void) { int i; for (i = 0; i < 10000; i++) { __asm__ __volatile__("nop"); } return 0; /* Success */ } : gcc -fpic -shared -o example.so example.c : stress-ng --plugin 1 --plugin-so ./example.so --plugin-method function stress_ . --plugin-ops N N . --plugin-so name . (Polling) -P N, --poll N N poll(2) ppoll(2) select(2) pselect(2) sleep(3) . ..TP --poll-fds N (file descriptors) poll/ppoll/select/pselect . select/pselect FD_SETSIZE pipe . --poll-ops N (workers) poll N bogo poll. --poll-random-us N N ppoll(2) pselect(2) . (Power maths functions) --powmath N N libm (sanity check) . --powmath-ops N N (bogo- operation) . --powmath-method method . : all cpow (complex double) cpowf (complex float) cpowl (complex long double) csqrt ( /) csqrtf ( /) csqrtl ( /) cbrt ( /) cbrtf ( /) cbrtl ( /) hypot () hypotf () hypotl () pow (double) powf (float) powl (long double) sqrt ( /) sqrtf ( /) sqrtl ( /) prctl (Prctl stressor) --prctl N N prctl(2) . prctl (child process) prctl . prctl . --prctl-ops N prctl N prctl L3 (L3 cache prefetching stressor) --prefetch N N (prefetch) L3 (benchmark) . x . 8 K . . . . --prefetch-l3-size N l3 --prefetch-method N . : builtin __builtin_prefetch(3) . . builtinl0 __builtin_prefetch(3) 0 (locality 0 hint). builtinl3 __builtin_prefetch(3) 3 (locality 3 hint). dcbt dcbt ppc64 L1 ( ppc64). dcbtst dcbtst ppc64 L1 ( ppc64). prefetcht0 prefetcht0 x86 ( x86). prefetcht1 prefetcht1 x86 ( ) ( x86). prefetcht2 prefetcht2 x86 ( ) ( x86). prefetchnta prefetchnta x86 ( ) ( x86). prfm_pldl1keep prfm aarch64 pld1keep ( ) ( aarch64). prfm_pldl2keep prfm aarch64 pld1keep ( ) ( aarch64). prfm_pldl3keep prfm aarch64 pld1keep ( ) ( aarch64). prfm_pldl1strm prfm aarch64 pld1strm ( ) ( aarch64). prfm_pldl2strm prfm aarch64 pld1strm ( ) ( aarch64). prfm_pldl3strm prfm aarch64 pld1strm ( ) ( aarch64). --prefetch-ops N prefetch N . ( ) 5 --prime N N GNU Multiple Precision Arithmetic Library . mpz_nextprime GMP /bin/bash: line 1: :w: command not found bogo-op . --prime-method [ factorial | inc | pwr2 | pwr10 ] . inc . lB2 lB l lx. factorial . . inc . . pwr2 . . pwr10 . . --prime-ops N N . --prime-progress . . --prime-start N N. ( 1e200 ) . (Priority inversion) --prio-inv N N mutex . FIFO . mutex (block) . (unrunnable) . --prio-inv-ops N N (bogo) / . --prio-inv-type [ inherit | none | protect ] mutex : inherit mutex . none mutex mutex . . protect mutex mutex ( ) . --prio-inv-policy [ batch | ext | idle | fifo | other | rr ] . <<>> (batch ext idle other) <<>> (fifo rr) . <> <> . (Privileged CPU instructions) --priv-instr N N . (trap ) SIGSEGV SIGILL . --priv-instr-ops N priv-instr N . /proc --procfs N N /proc /proc/self ( ). --procfs-ops N procfs N (bogo). bogo . / pwrite/pread lseek --pseek N N pwrite(2) pread(2) lseek(2) . pwrite pread . pthreads ( ) fork(2) . pwrite pread I/O . I/O lseek(2)/write(2) lseek(2)/read(2) lseek pwrite pread . --pseek-io-size N / (I/O) / . . --pseek-ops N N . --pseek-rand / . Pthread --pthread N N pthread ( pthread ). pthread pthread . --pthread-max N N pthread . pthread (soft limit) . --pthread-ops N pthread N (bogo) pthread. Ptrace --ptrace N N fork ptrace(2) (trace) . --ptrace-ops N ptrace N bogo. (Pointer Chasing) --ptr-chase N N (page) . . . (pointer fetching) (pointer dereferencing) (cache-read) . heap mmap ..TP --ptr-chase-ops N N . --ptr-chase-pages N . (pty) --pty N N ioctl(2) pty . --pty-max N N 65536 . 8..65536 . --pty-ops N pty N (bogo ops) . Qsort -Q, --qsort N N qsort(3) . --qsort-method [ qsort-libc | qsort-bm ] libc qsort J. L. Bentley M. D. McIlroy qsort. libc . --qsort-ops N qsort N (bogo qsorts). --qsort-size N 262144 (256 x 1024) . (Quota) --quota N N quotactl(2) Q_GETQUOTA Q_GETFMT Q_GETINFO Q_GETSTATS Q_SYNC . CAP_SYS_ADMIN . --quota-ops N N quotactl. --race-sched N N (CPU affinity) . (race conditions) . --race-sched-method [ all | next | prev | rand | randinc | syncnext | syncprev ] CPU . : all race-sched : next CPU CPU . prev CPU CPU CPU . rand CPU . randinc CPU + 1..4 CPU. syncnext race-sched CPU (round-robin) . syncprev race-sched CPU (round-robin) . --race-sched-ops N N . Radixsort --radixsort N N radixsort(3) . --radixsort-method [ radixsort-libc | radixsort-nonlibc ] libc radixsort radixsort. libc . --radixsort-ops N radixsort N (bogo radixsorts). --radixsort-size N 262144 (256 x 1024) . (RAM) --ramfs N N ramfs tmpfs ( ). (mount umount) ramfs tmpfs mount(2) umount(2) 5.2 fsopen(2) fsmount(2) fsconfig(2) move_mount(2) ( ) . 2 . --ramfs-fill ramfs fallocate(2) write(2) . --ramfs-ops N N ramfs. --ramfs-size N ramfs ( ). (Raw device) --rawdev N N / (direct IO) . ( 0) . . rawdev ( --rawdev-method ). (root) . --rawdev-method method rawdev : all rawdev : sweep 0 128 . wiggle 128 1024 . ends 128 . random 256 . burst 256 . --rawdev-ops N rawdev N (bogo operations) . (Random list stressor) 5 --randlist N N . (cache thrashing) . (heap) (shared anonymous memory mapping) TLB . --randist-compact . . --randlist-items N N . . --randlist-ops N randlist N . --randlist-size N N . (payload) . (Localhost raw socket stressor) 5 --rawsock N N (raw sockets) localhost . CAP_NET_RAW . --rawsock-ops N rawsock N . --rawsock-port P P. N rawsock P P + (N - 1) ( ). . (Localhost ethernet raw packets stressor) 5 --rawpkt N N (ethernet) localhost (loopback) . CAP_NET_RAW . --rawpkt-ops N rawpkt N . --rawpkt-port N P. N rawpkt P P + (N - 1) ( ). . --rawpkt-rxring N (RX ring) N TPACKET_V . N . UDP (Localhost raw UDP packet stressor) 5 --rawudp N N localhost UDP (PID) . CAP_NET_RAW . --rawudp-if NAME NAME. NAME (up) (lo) . --rawudp-ops N rawudp N . --rawudp-port N P. N rawudp P P + (N - 1) ( ). . (Random number generator stressor) 5 --rdrand N N (on-chip) . rdrand x86 darn PowerPC . --rdrand-ops N rdrand N rdrand ( = ). --rdrand-seed rdseed rdrand ( x86). (Read-ahead stressor) 5 --readahead N N readahead(2) (seek) / (I/O) / . . . --readahead-bytes N readahead . b k m g . --readahead-ops N readahead N . (Reboot stressor) 5 --reboot N N reboot(2) . PID reboot . (magic values) reboot . --reboot-ops N reboot N . POSIX (POSIX regular expressions stressor) 5 --regex N N POSIX . C regex . --regex-ops N N regex. (CPU registers stressor) 5 --regs N N (CPU) . (bogo-op) . GCC (register annotations) . --regs-bitflip () . . --regs-ops N regs N . (Memory page reordering stressor) 5 --remap N N remap_file_pages(2) . : . --remap-mlock mlock(2) (huge pages) mmap (swap out) . --remap-ops N N . --remap-pages N . 5 -R N, --rename N N . --rename-ops N N bogo. 5 --resched N N . nice nice ( nice) . nice SCHED_OTHER SCHED_BATCH SCHED_IDLE sched_yield(2) . -v yield nice N . --resched-ops N N sched_yield . 5 --resources N N . heap (stack) ( eventfd memoryfd userfaultfd ) . --resources-mlock mlock(2) mmap swap . --resources-num N N . . --resources-ops N N fork . --resources-procs N . . 5 --revio N N . (sparse holes) . --aggressive --revio-opts revio --revio-opts I/O . --revio-bytes N N revio 1 (1 GB) . b k m g . --revio-opts list . --hdd-opts iovec readahead (readahead) . --revio-ops N revio N bogo. --revio-write-size N . . 5 --ring-pipe N N (pipes) poll . . read write . splice splice (in-kernel) . --ring-pipe-num N . . --ring-pipe-ops N N . --ring-pipe-size N . . --ring-pipe-splice splice ( splice() ). Rlimit 5 --rlimit N N rlimit(2) SIGXCPU SIGXFSZ SIGSEGV . --rlimit-ops N N bogo SIGXCPU SIGXFSZ SIGSEGV. VM 5 --rmap N N (VM reverse-mapping) . (file-backed) /. . msync . --rmap-ops N N bogo / rmap. --rmap-procs N . . 5 --rofs N N . access(2) read(2) lstat(2) listxattr(2) mmap(2) lseek(2) flock(2) statx(2) . --rofs-dir directory . --rofs-ops N N bogo . 5 --rotate N N (unsigned integer) . ( ) bogo-op . --rotate-method method . 'all' . lB2 lB l lx. all rotate ( ): rol8 ror8 rol16 ror16 rol32 ror32 rol64 ror64 rol128 ror128 --rotate-ops N N (bogo) . (rseq) () 5 --rseq N N rseq(2) . (critical section) . (abort handler) rseq SIGSEGV rseq rseq . . --rseq-ops N N (bogo) rseq . bogo rseq rseq . (RTC) 5 --rtc N N (RTC) /dev/rtc /sys/class/rtc/rtc0 . () RTC . . --rtc-ops N N (bogo) RTC . (Scheduler mix) 5 --schedmix N N . . --schedmix-cpumix CPU (CPU mixing). --schedmix-ops N N . --schedmix-procs N . (Scheduling policy) 5 --schedpolicy N N SCHED_OTHER SCHED_BATCH SCHED_IDLE SCHED_FIFO SCHED_RR SCHED_DEADLINE SCHED_EXT . (real time) . --schedpolicy-cpumix CPU (CPU mixing). --schedpolicy-ops N N (bogo) . --schedpolicy-rand . . (SCTP) 5 --sctp N N Stream Control Transmission Protocol (SCTP) . / / . --sctp-domain D ipv4 . ipv4 ipv6 . --sctp-if NAME NAME. NAME (up) loopback (lo) . --sctp-max-size N . --sctp-ops N sctp N (bogo). --sctp-port P sctp P. N sctp P P + (N - 1) ( ). . --sctp-sched [ fc | fcfs | prio | rr | wfq ] SCTP fc ( ) fcfs ( ) prio () rr ( round-robin) wfq ( ). (SEAL) () 5 --seal N N SEAL fcntl(2) (page) memfd_create(2) . SEAL (seal) . ( ). --seal-ops N N (bogo) (seal) . (seccomp) 5 --seccomp N N Secure Computing . /dev/null . seccomp write SIGSYS seccomp . (audit log) . CAP_SYS_ADMIN . --seccomp-ops N seccomp N seccomp. ( >= 5.11) 5 --secretmem N N memfd_secret(2) mmap . ftruncate mmap ( ). (unmapping) (fragmented) . (OOM) . 5.11+ "secretmem=" . --secretmem-ops N secretmem N . (seek) 5 --seek N N seek / (I/O) / . 16 GB . --seek-ops N seek N (bogo) (seek). --seek-punch (hole punch) (8 K) (extents) seek ( ). --seek-size N . I/O CPU . I/O I/O . b k m g . POSIX 5 --sem N N wait post POSIX . (contention) . (context switching) ..TP --sem-ops N N bogo . --sem-procs N N . --sem-shared sem. . System V 5 --sem-sysv N N wait post System V . . (context switching) . --sem-sysv-ops N N bogo System V. --sem-sysv-procs N N System V . --sem-sysv-setall semval . SETALL semctl GETALL . Sendfile 5 --sendfile N N sendfile(2) /dev/null . . sendfile 4 MB . sendfile . --sendfile-ops N sendfile N bogo sendfile. --sendfile-size N sendfile . 4 MB . b k m g . Sessions 5 --session N N (session ID) . (wait) (orphaned) init (reap) . --session-ops N N . (Setting data in the Kernel) 5 --set N N : setgid(2) sethostname(2) setpgid(2) setpgrp(2) setuid(2) setgroups(2) setreuid(2) setregid(2) setresuid(2) setresgid(2) setrlimit(2). . --set-ops N set N bogo (set). Shellsort 5 --shellsort N N shellsort(3) . --shellsort-ops N shellsort N bogo shellsort. --shellsort-size N 262144 (256 x 1024) . POSIX 5 --shm N N POSIX . 8 MB . --shm-bytes N POSIX . b k m g . --shm-mlock mlock(2) (swap out) . --shm-objs N . --shm-ops N N bogo POSIX. System V 5 --shm-sysv N N System V . 8 MB . --shm-sysv-bytes N . b k m g . --shm-sysv-mlock mlock(2) (swap out) . --shm-sysv-ops N N bogo . --shm-sysv-segs N . SIGABRT 5 --sigabrt N N SIGABRT abort(3) . --sigabrt-ops N sigabrt N SIGABRT. SIGBUS 5 --sigbus N N (bus errors) (misaligned access) . --sigbus-ops N sigbus N bogo. SIGCHLD 5 --sigchld N N SIGCHLD . (CLD_EXITED) (CLD_KILLED) (CLD_STOPPED) (CLD_CONTINUED) . --sigchld-ops N sigchld N SIGCHLD. SIGFD () 5 --sigfd N N SIGRT signalfd(2) ( ). (context switch) ..TP --sigfd-ops sigfd N SIGUSR1. SIGFPE 5 --sigfpe N N SIGFPE . --sigfpe-ops N sigfpe N SIGFPE. SIGHUP 5 --sighup N N raise(2) ( SIGHUP ) SIGHUP . --sighup-ops N sighup N SIGHUP. SIGILL 5 --sigill N N SIGILL . --sigill-ops N sigill N SIGILL. SIGIO 5 --sigio N N pipe SIGIO . I/O SIGIO . --sigio-ops N sigio N SIGIO. Signal 5 --signal N N signal : SIG_IGN ( ) SIGCHLD SIG_DFL ( ). SIGCHLD SIGCHLD . SIGCHLD . signal C signal sigaction . --signal-ops N signal N . 5 --signest N N . . . -v . --signest-ops N N . 5 --sigpending N N SIGUSR1 . SIGUSR1 SIGUSR1 sigpending(2) . . --sigpending-ops N sigpending N / sigpending. SIGPIPE 5 --sigpipe N N pipe SIGPIPE . clone(2) fork(2) . --sigpipe-ops N N N SIGPIPE. 5 --sigq N N sigqueue(3) SIGUSR1 sigwaitinfo(2) . --sigq-ops N sigq N . 5 --sigrt N N SIGRTMIN SIGRMAX . siqueue(2) RT sigwaitinfo(2) . RT sigqueue(2) . --sigrt-ops N sigrt N sigqueue. SIGSEGV 5 --sigsegv N N (segmentation faults) vdso x86 . --sigsegv-ops N sigsegv N . SIGSTOP 5 --sigstop N N SIGSTOP SIGCHLD SIGCONT . --sigstop-ops N N SIGSTOP SIGCONT. 5 --sigsuspend N N sigsuspend(2) SIGUSR1 . SIGUSR1 . sigsuspend . --sigsuspend-ops N sigsuspend N sigsuspend. SIGTRAP 5 --sigtrap N N SIGTRAP . SIGTRAP raise(SIGTRAP) . x86 SIGTRAP int 3 . --sigtrap-ops N sigtrap N SIGTRAP. SIGURG 5 --sigurg N SIGURG TCP/IP IPv4 ..TP --sigurg-ops N sigurg N SIGURG. SIGVTARLM 5 --sigvtalrm N N SIGVTARLM itimer ITIMER_VIRTUAL (busy loop) getitimer ITIMER_VIRTUAL (CPU) . --sigvtalrm-ops N sigvtalrm N SIGVTARLM. SIGXCPU 5 --sigxcpu N N SIGXCPU . sched_yield(2) SIGXCPU . --sigxcpu-ops N sigsxcpu N (bogo) SIGXCPU. SIGXFSZ 5 --sigxfsz N N SIGXFSZ . SIGXFSZ . --sigxfsz-ops N sigsxfsz N (bogo) SIGXFSZ. skiplist 5 --skiplist N N skiplist . . . --skiplist-ops N skiplist N skiplist. --skiplist-size N ( ) skiplist. 1 K 4 M . 5 --sleep N N (thread) (sleep) . . --sleep-max P P . . --sleep-ops N N (bogo) sleep. (SMI) 5 --smi N N (APM) 0xb2 (SMIs) (SMM) ring -2 x86 . --pathological (root) x86 . . (naive) SMI . --smi-ops N N SMI. 5 -S N, --sock N N . / . --sock-domain D ipv4 . ipv4 ipv6 unix . --sock-if NAME NAME. NAME (up) loopback (lo) . --sock-msgs N N / . . N ( /proc/sys/net/netfilter/nf_conntrack_max ). --sock-nodelay TCP Nagle . . --sock-ops N N (bogo). --sock-opts [ random | send | sendmsg | sendmmsg ] send(2) . send(2) sendmsg(2) sendmmsg(2) . sendmmsg . --sock-port P P. N P P + (N - 1) ( ). . --sock-protocol P P tcp . tcp mptcp ( ) . --sock-type [ stream | seqpacket ] . stream . seqpacket unix . --sock-zerocopy zerocopy send recv MSG_ZEROCOPY . 5 --sockabuse N N . (gracefully) . --sockabuse-ops N N . --sockabuse-port P P. N sockabuse P P + (N - 1) ( ). . () 5 --sockdiag N N netlink sock_diag ( ). UDIAG_SHOW_NAME UDIAG_SHOW_VFS UDIAG_SHOW_PEER UDIAG_SHOW_ICONS UDIAG_SHOW_RQLEN UDIAG_SHOW_MEMINFO AF_UNIX . --sockdiag-ops N N sock_diag. 5 --sockfd N N CMSG(3) (UNIX domain socket) . / /dev/null CMSG . --sockfd-ops N sockfd N (bogo)..TP --sockfd-port P P. N sockfd P P + (N - 1) ( 1024 65535 ). 51456 . --sockfd-reuse /dev/null . (Opening network socket stressor) 5 --sockmany N N 100000 TCP/IP 10000 . --sockmany-if NAME NAME. NAME (up) (lo) . --sockmany-max-size N 1 32768 8. --sockmany-ops N N . --sockmany-port P P. N sockmany P P + (N - 1) ( 1024 65535 ). 51712 . / (Socket I/O stressor) 5 --sockpair N N / / . / / . --sockpair-max-size N 1 65535 4096. --sockpair-ops N N (bogo ops). (Softlockup stressor) 5 --softlockup N N (softlockup) "" SCHED_FIO SCHED_RR . CAP_SYS_NICE CPU . (watchdog timeout) . --softlockup-ops N N (bogo). (Sparse matrix stressor) 5 --sparsematrix N N (hashing) Judy ( 64 ) () ( ) (red-black tree) . . 500 x 500 5000 2% . --sparsematrix-items N N . N N 100% . --sparsematrix-method [ all | hash | hashjudy | judy | list | mmap | qhash | rb ] . "all" . lB2 lB l lx. all sparsematrix ( ): hash (hash table) (heap) (x, y). hashjudy x Judy y (x, y). judy Judy (x, y) . list y x (x, y) . mmap mmap . (x, y) . mmap (out of memory killer) . qhash . calloc hash . rb (x, y). splay (splay tree) (x, y). --sparsematrix-ops N N sparsematrix. --sparsematrix-size N N x N. (posix_spawn) () --spawn N N posix_spawn(3) stress-ng (exec) . . --spawn-ops N (spawn) N (bogo spawns). (Speculative Rollback stressor) --spec-rollback N N (branch misprediction) (rollback flush) . 256 64 . --spec-rollback-ops N N x 1024 . --spec-rollback-size N N . 256 16 8388608. N 2 . --spinmem N N (busy spin loops) . 0 1 . 0 1 . . CPU . / 32 . --spinmem-affinity spinmem CPU spinmem. --spinmem-method method / 32 . / 128 / (toolchains) . spinmem :.sp 8bit / 16bit / 32bit / 64bit / 128bit / ( ) 8bitatomic / ( ) 16bitatomic / ( ) 32bitatomic / ( ) 64bitatomic / ( ) --spinmem-ops N N (bogo ops) spinmem . spinmem . --spinmem-yield (scheduling yield) / spinmem. Splice () --splice N /dev/zero /dev/null (pipe) splice(2). . --splice-bytes N N splice 64 K . b k m g . --splice-ops N N splice . (Stack) --stack N N . brk OOM killer . --stack-fill (touch) . . --stack-mlock mlock(2) (swap out) . --stack-ops N N . --stack-pageout ( madvise(2) MADV_PAGEOUT ). --stack-unmap (unmap) . . --stackmmap N N . msync(2) ( ). . --stackmmap-ops N N . statmount listmount --statmount N N (mounts) / listmount statmount ( ). --statmount-ops N N . libc --str N N libc . --str-method strfunc libc . : all index rindex strcasecmp strcat strchr strcoll strcmp strcpy strlen strncasecmp strncat strncmp strrchr strxfrm. string(3) . `all' . --str-ops N N . STREAM --stream N N STREAM "Sustainable Memory Bandwidth in High Performance Computers" John D. McCalpin . (L3 cache) : copy c[i] = a[i] scale b[i] = scalar x c[i] add c[i] = a[i] + b[i] triad a[i] = b[i] + (c[i] x scalar) STREAM stress-ng STREAM ( ) . STREAM STREAM . . volatile // . --stream-discontiguous mmap <<>>. --stream-index N stream a b c. . 0 ( ) 3 . L1 L2 L3 / . --stream-l3-size N (L3 cache) . b k m g . L3 stress-ng 4 MB . --stream-mlock stream mlock(2) (swap out). --stream-madvise [ collapse | hugepage | nohugepage | normal ] madvise(2) stream. madvise `normal' . `normal' ..TP --stream-ops N N (bogo) copy scale add triad . --stream-prefetch gcc (prefetching) . . --stream-index 0 . / --strnum 1 N / libc . (bogo) (int long long long) (float double long double) . --strnum-ops N N (bogo) /. --strnum-method method : all atoi atoi() atol long atol() atoll long long atoll() strtoul long strtoul() strtoull long long stroull() sscanf-i sscanf() sscanf-li long sscanf() sscanf-lli long long sscanf() sscanf-u sscanf() sscanf-lu long sscanf() sscanf-llu long long sscanf() snprintf-i snprintf() snprintf-li long snprintf() snprintf-lli long long snprintf() strtof float strtof() strtod double strtof() strtold long double strtof() sscanf-f float sscanf() sscanf-d double sscanf() sscanf-ld long double sscanf() strfromf float strfromf() strfromd double strfromd() strfroml long double strfroml() swap ( ) --swap N N swap ( ). swap ( ) . CAP_SYS_ADMIN . swap swap swap (kernel log) . --swap-ops N swap N swapon/swapoff. --swap-self swap ( swap out). -s N, --switch N N (context switching) / . pipe . --switch-freq F F . (CPU) . --switch-method [ mq | pipe | sem-sysv ] / : mq POSIX . . pipe pipe . sem-sysv SYSV / . --switch-ops N N (bogo). (Symlink) --symlink N N . --symlink-ops N symlink N (bogo). --symlink-sync (dirty data) . (sync_file_range) --sync-file N N sync_file_range(2) . : . SYNC_FILE_RANGE_WAIT_BEFORE SYNC_FILE_RANGE_WRITE SYNC_FILE_RANGE_WAIT_AFTER ..TP --sync-file-bytes N . Bytes KBytes MBytes GBytes b k m g . --sync-file-ops N sync-file N (bogo sync). --syncload N N N . C-state CPU . +-10% (jitter) . --syncload-msbusy M . --syncload-mssleep M . --syncload-ops N syncload N /. --sysbadaddr N N . (null pointers) (text only) (unaligned) . --sysbadaddr-ops N sysbadaddr N (bogo system calls). --syscall N N . (capabilities) . . --syscall-method method . . : all fast10 fast25 fast50 fast75 fast90 geomean1 geomean1 2 x geomean1 3 x --syscall-rank [ name | average | min | max ] . --syscall-ops N N . --sycsall-top N N . N . --sysinfo N N . times(2) . sysinfo(2) statfs(2) . --sysinfo-ops N sysinfo N (bogo ops). () --sysinval N N . (crash) (blocklist) . . . --sysinval-ops N sysinval N . sysfs /sys () --sysfs N N /sys ( ). . --sysfs-ops N sysfs N (bogo read). bogo ops . Tee () --tee N (pipes) /dev/null tee(2). . --tee-ops N N tee. () -T N, --timer N N 1 MHz ( ) . (signal handler) (bogo timer op) . --timer-freq F F 1 1000000000 ( ). stress-ng . : --timer-slack 0 (coalescing) . --timer-ops N N ( ). --timer-rand +-12.5% (jitter) . . Timerfd () --timerfd N N timerfd (1 MHz) ( ) . select(2) bogo timerfd . --timerfs-fds N N timerfd . --timerfd-freq F F ( ). stress-ng . --timerfd-ops N timerfd N bogo timerfd ( ). --timerfd-rand timerfd (jitter) +-12.5%. . Timer Mix --timermix N N timer itimer . (handle) bogo . ( ) : CLOCK_REALTIME CLOCK_MONOTONIC CLOCK_PROCESS_CPUTIME_ID CLOCK_THREAD_CPUTIME_ID CLOCK_BOOTTIME CLOCK_TAI. itimer : ITIMER_REAL ITIMER_VIRTUAL ITIMER_PROF. timer itimer . itimer . --timermix-ops N N timer itimer. Time warp --time-warp N N (monotonic) (reverse time warping) . (time wrap- around) . clock_gettime(2) gettimeofday(2) time(2) getrusage(2) . . --time-warp-ops N N . TLB shootdowns NUMA --tlb-numa N N (TLB shootdown) NUMA (bind) pthread (CPU) . x86 TLB L1 L2 mmap . . NUMA . --tlb-numa-entries N TLB . --tlb-numa-nombind NUMA mbind(2) NUMA . --tlb-numa-nopageout (page- out) mmap . TLB shootdown . --tlb-ops N N pthread TLB. TLB . --metrics . TLB shootdowns --tlb-shootdown N N (TLB shootdowns) . . TLB (flush) TLB shootdown . --tlb-shootdown-ops N N bogo TLB shootdown. Tmpfs --tmpfs N N tmpfs mmap . --tmpfs-mmap-async msync (asynchronous) --tmpfs-mmap-file . --tmpfs-mmap-file tmpfs msync (synchronous) . --tmpfs-ops N tmpfs N bogo mmap. (Touching files) --touch N (touch) open(2) creat(2) (unlink) . bogo-op dentry . I/O bogo-op CPU . --touch-method [ random | open | creat ] open(2) creat(2) open(2) O_CREAT creat(2). --touch-ops N touch N . --touch-opts [ all | direct | dsync | excl | noatime | sync ] . : all direct dsync excl noatime sync direct / (I/O) O_DIRECT. dsync (metadata) O_DSYNC. excl ( ). noatime . sync O_SYNC. (Tree data structures) --tree N N . AVL ( avl) (binary) (btree) - (rb) (splay) treap . . --tree-method [ all | avl | binary | btree | rb | splay | treap ] . ( `all`)..TP --tree-ops N N (bogo ops). () . --tree-size N N . --trig N N libm sin cos sincos ( ) tan float double long double . (bogo- operation) . --trig-method function . . : all cos ( double) cosf ( float) cosl ( long double) sin ( double) sinf ( float) sinl ( long double) sincos ( double) sincosf ( float) sincosl ( long double) tan ( double) tanf ( float) tanl ( long double) --trig-ops N N (bogo- operations). (TSC) --tsc N N (TSC) ( ) . tsc x86 mftb ppc64 rdcycle RISC-V tick SPARC rdtime.d Loong64 . --tsc-lfence lfence tsc ( x86). --tsc-ops N tsc N . --tsc-rdtscp rdtscp rdtsc ( x86). --tsc-lfence . --tsearch N N tsearch(3) tfind(3) tdelete(3) . . . --tsearch-ops N tsearch N . --tsearch-size N ( ) tsearch. 1 K 4 M . --tun N N UDP . IPv4 192.168.*.* . --tun-ops N N /// . --tun-port P P. N tun P P + (N + 16) - 1 ( ). . --tun-tap tap () tun (). UDP --udp N N UDP . / . ( ) . --udp-domain D ipv4 . ipv4 ipv6 . --udp-gro UDP-GRO ( ) . --udp-if NAME NAME. NAME (up) (lo) . --udp-lite UDP-Lite (RFC 3828) ( ipv4 ipv6). UDP-Lite 7.1 . --udp-max-size N . --udp-ops N udp N . --udp-port P P. N udp P P + (N - 1) ( ). . UDP --udp-flood N N UDP (flood). IP . AF_PACKET . --udp-flood-domain D ipv4 . ipv4 ipv6 . --udp-flood-if NAME NAME. NAME (up) (lo) ..TP --udp-flood-max-size N . --udp-flood-ops N udp-flood N bogo. umask --umask N N umask fstat unlink (file mode) . umask 0000 0777 ( ) . --umask-ops N N umask 0000 0777. Umount --umount N N (mount) (racy unmounting) tmpfs ramfs . : (force umount) /proc/mounts. mount umount (race conditions) umount . --umount-ops N umount N bogo mount/umount. Unlink --unlink N N unlink () . . --unlink-ops N N bogo unlink . Unshare () --unshare N N (fork) (execution context) unshare(2) . ( ). --unshare-ops N N bogo unshare. Uprobe () --uprobe N N libc getpid(2) uprobe . CAP_SYS_ADMIN uprobe . --uprobe-ops N uprobe N . /dev/urandom () -u N, --urandom N N /dev/urandom ( ). . --urandom-ops N urandom N bogo urandom ( ). () --userfaultfd N N (write page faults) (anonymously mapped) userfaultfd(2) . (major page faults) (context switch) . ( ). --userfaultfd-bytes N mmap N userfaultfd 16 MB . b k m g . --userfaultfd-ops N userfaultfd N . SIGSYS --usersyscall N N prctl . SIGSYS (ENOSYS) ( SIGSYS) PR_SET_SYSCALL_USER_DISPATCH prctl . --usersyscall-ops N N SIGSYS. --utime N N . (CPU bound) (flush) . --utime-fsync (flush) . / (I/O bound) (dirty metadata writes) . --utime-ops N utime N bogo utime. --varyload N N N varyload . --varyload-type varyload . varyload SIGSTOP SIGCONT . --varyload-ops N N bogo varyload. --varyload-ms M M ( ). --varyload-type . --varyload-sched P batch deadline ext fifo idle rr other . --varyload-method M (CPU). : all : fma - fused-multiply-add . getpid PID getpid(2). inc64 . memmove () memmove(3). memread . memset memset(3). mcw64 mwc. nop no-op. pause pause/yield (memory barrier) . procname . random (spin-loop). strnum / x86 . sqrt (double precision) sqrt(3) hypot(3). time time(2). vecfp . vecint . --varyload-type T . : lB2 lB l lx. all varyload . brown (brown noise) / . triangle N . saw-inc N . saw-dec N N. pulse N . random 1..N. (Virtual dynamic shared object stressor) --vdso N N (worker) vDSO ( ) . vDSO . --vdso-func F vDSO F vDSO . clock_gettime(2) getcpu(2) gettimeofday(2) time(2) . --vdso-ops N N vDSO. (Vector integer comparison operations stressor) --veccmp N N (worker) . : x x x x x . . --veccmp-ops N N (bogo) . (Vector floating point operations stressor) --vecfp N N (worker) ( ) . -v . x86 target clones gcc/clang mmx sse avx . --vecfp-method method vecfp. . all floatv128add floatv64add floatv32add floatv16add floatv8add floatv128mul floatv64mul floatv32mul floatv16mul floatv8mul floatv128div floatv64div floatv32div floatv16div floatv8div doublev128add doublev64add doublev32add doublev16add doublev8add doublev128mul doublev64mul doublev32mul doublev16mul doublev8mul doublev128div doublev64div doublev32div doublev16div doublev8div doublev128neg doublev64neg doublev32neg doublev16neg doublev8neg --vecfp-ops N N - (bogo-operation) . - . - 65536 x 2 x 16 . 5 --vecmath N N . : 16 x 8 8 x 16 4 x 32 2 x 64 1 x 128 . . --vecmath-ops N N - . 5 --vecshuf N N (shuffle ). - . -v . (load) / (shuffle/permute) / (packing/unpacking) (store) . --vecshuf-method method . . lB2 lb l lx. all u8x64 u16x32 u32x16 u64x8 u128x4 ( ) --vecshuf-ops N N - . - 4 x 65536 . --vecwide N N . -v vecwide . vecwide . --vecwide-ops N N - ( ) . (verity) --verity N N ioctl verity FS_IOC_ENABLE_VERITY FS_IOC_MEASURE_VERITY . verity ( ext4 f2fs Linux) verity . (extent) verity . FS_VERITY_FL verity . --verity-ops N verity N verity verity unlink. vfork --vfork N N vfork . --vfork-max P P . (zombie) (reap ) . --vfork-max --vfork . --vfork-ops N vfork N -. vfork --vforkmany N N vfork / vfork . vfork . --vforkmany-ops N vforkmany N vfork. --vforkmany-vm madvise(2) vfork. madvise(2) MADV_MERGEABLE MADV_WILLNEED MADV_HUGEPAGE MADV_RANDOM . Linux. --vforkmany-vm-bytes N (mmap) N vm (64 MB) . --vforkmany-vm . (%) b k m g . -m N, --vm N N mmap(2)/munmap(2) . swap Linux (OOM killer) . --vm-bytes N (mmap) N vm (256 MB) . (%) b k m g . --vm-discontiguous mmap <<>> . --vm-flush (cache flush) . --vm-hang N N (unmap) . 0 . --vm-keep . --vm-locked MAP_LOCKED mmap ( 2.5.37 ). mlock(2) . --vm-madvise advice <<>> (advice) madvise vm . madvise `normal` `collapse` `dontneed` `hugepage` `mergeable` `nohugepage` `normal` `random` `sequential` `unmergeable` `willneed` . madvise mmap . madvise(2) ..TP --vm-method method vm . . (workers) vm : . (Initialised). . . (Exercised). . vm (strides) . . (Checked). . vm <> 2^64 . () . . memtest86 . vm . vm : all vm . cache-lines . . cache-stripe . checkerboard / . . flip () . . fwdrev . . galpat-0 (galloping pattern zeros). 0 4096 1 . 1 0 1 . galpat-1 (galloping pattern ones). 1 4096 0 . 0 1 0 . gray ( ) . grayflip . incdec . / . inc-nybble ( ) . lfsr32 x^32 + x^31 + x^29 + x + 1. 2^32 - 1 ( 0) . modulo-x . . . . / . move-inv . . mscan 1 0 . one-zero . . prime-0 . . prime-1 . . prime-gray-0 ( ) . . . prime-gray-1 ( ) . . . prime-incdec . rand-set . . . rand-sum . read64 32 x 64 bogo. bogo . . ror // . rowhammer rowhammer. (cache flush) . (bit flipping) . swap . . . / . walk-0a (low). . walk-0d ( ) . . walk-1a (high). . walk-1d ( ) . . walk-flush / / . (data cache miss) . write64 32 x 64 bogo. bogo . . . write64ds 32 x 64 (direct store) bogo. bogo . (WC) x86 movediri gcc clang . . write64nt 32 x 64 (non-temporal) bogo. bogo . x86 sse2 gcc clang . . write1024v 1 x 1024 bogo ( ). bogo . . . wrrd128nt ( ). (hammer) . ( ) . . zero-one . . --vm-nt (non- temporal) x86 ( ). --vm-numa NUMA . NUMA . --vm-ops N vm N (bogo ops). --vm-populate ( prefault) (swapping) . MAP_POPULATE ( .. ). --vm-addr N N . (cache) TLB . . --vm-addr-method method vm. . vm : all vm . bitposn max_stride max_stride max_stride . (flip) . dec . decinv dec . flip /. gray . grayinv gray . inc . incinv inc . pwr2 . pwr2inv pwr2 . rev . revinv rev . --vm-addr-mlock mlock(2) (swap out) . --vm-addr-numa NUMA . NUMA . --vm-addr-ops N N N (bogo). () --vm-rw N N process_vm_writev(2) process_vm_readv(2) / . . --verify . --vm-rw-bytes N mmap N vm-rw . b k m g . --vm-rw-ops N vm-rw N / . --vm-segv N N (unmap) SIGSEGV . --vm-segv-ops N N SIGSEGV (bogo) vm-segv. Vmsplice () --vm-splice N /dev/null (pipe) vmsplice(2) splice(2). . --vm-splice-bytes N N vmsplice . b k m g . --vm-splice-ops N N vm-splice. (VMA) --vma N M mmap(2) munmap(2) mlock(2) munlock(2) madvise(2) msync(2) mprotect(2) mincore(2) pthread . VMA . . --vma-ops N vma N . --vnni N N (VNNI) . . . ( ). --vnni-intrinsic vnni (intrinsic) VNNI ..TP --vnni-method N VNNI : all VNNI vpaddb512 x (x86 vpaddb) vpaddb256 x (x86 vpaddb) vpaddb128 x (x86 vpaddb) vpaddb ( ) vpdpbusd512 x (x86 vpdpbusd) vpdpbusd256 x (x86 vpdpbusd) vpdpbusd128 x (x86 vpdpbusd) vpdpbusd ( ) vpdpwssd512 x (x86 vpdpwssd) vpdpwssd256 x (x86 vpdpwssd) vpdpwssd128 x (x86 vpdpwssd) vpdpwssd ( ) --vnni-ops N N VNNI . bogo- op . --wait N N (worker) pause(2) . SIGCONT waitpid(2) waitid(2) . --wait-ops N N (bogo wait) . --waitcpu N N . x86 pause tpause umwait ( ) nop. ARM yield . PPC64 yield mdoio mdooom . RISC- V pause . Loong64 dbar . openRISC psync . no- op . --waitcpu-ops N N . (Watchdog) --watchdog N N /dev/watchdog ioctl(2) watchdog . (magic close) (reboot) watchdog . (root) --pathological Linux . --watchdog-ops N N watchdog . Libc --wcs N N (wide character string) libc . --wcs-method wcsfunc libc . : all wcscasecmp wcscat wcschr wcscoll wcscmp wcscpy wcslen wcsncasecmp wcsncat wcsncmp wcsrchr wcsxfrm. "all" . --wcs-ops N N . --workload N N (sleep) . . ( ) . S Q S / Q . L Q x L / 100 . --workload-threads . . (bursty) . --workload-load L . Q x L / 100. --workload-method method . (tight spin- loop) . : all : fma - fused-multiply-add . getpid PID getpid(2) . inc64 (increment). memmove memmove(3) ( ). memread . memset memset(3) . mcw64 mwc . nop no-op . pause pause/yield (memory barrier) . procname . random (spin-loop). strnum / x86 . sqrt (double precision) sqrt(3) hypot(3) . time time(2) . vecfp . vecint . --workload-sched [ batch | deadline | ext | fifo | idle | other | rr ] . deadline fifo rr (root) . --workload-slice-us S . ( ) . --workload-quanta-us Q (work item) . ( ) . --workload-threads N N (workqueue) ( ). N . . --workload-dist [ cluster | even | poisson | random1 | random2 | random3 ] cluster . : lB2 lB l lx. cluster / / . . even poisson ( ). random1 . random2 . random3 . --workload-ops N N (bogo- operations) . x86 cpuid --x86cpuid N N cpuid x86 (leaf) . --x86cpuid-ops N N cpuid . x86-64 syscall () --x86syscall N N syscall x86-64 getcpu(2) geteuid(2) getgid(2) getpid(2) gettimeofday(2) time(2) vsyscall . . --x86syscall-func F syscall F . F getcpu geteuid getgid getpid gettimeofday time . --x86syscall-ops N N x86syscall . --xattr N N (extended attributes) . --xattr-ops N N . yield -y N, --yield N N sched_yield(2) . sched_yield(2) (context switching) . --yield-ops N yield N sched_yield(2) . --yield-procs N . . --yield-sched [ batch | deadline | ext | fifo | idle | other | rr ] . deadline fifo rr (root) . /dev/zero --zero N N /dev/zero read(2) lseek(2) ioctl(2) mmap(2) . /dev/zero --zero-read . --zero-ops N zero N /dev/zero . --zero-read /dev/zero /dev/zero . zlib --zlib N N zlib . : (pipe) . CPU (cache) . --zlib-level L (..) 0 = 1 = 9 = . --zlib-mem-level L zlib . . 1 . 9 . --zlib-method method zlib . . . zlib : 00ff 0x00 0xFF . ascii01 (ASCII) . asciidigits . bcd (packed BCD) .. (nybble) . binary . brown ( / ). double sin(). fixed 0x04030201 . gcr x x group coded recording (GCR) . GCR GCR . gray (Gray codes) . inc16 . latin Lorem Ipsum. lehmer (Lehmer) . lfsr32 (Galois LFSR) x^32 + x^31 + x^29 + x + 1. 2^32 - 1 ( ). logmap Xn+1 = r x Xn x (1 - Xn) r > ~ 3.56994567 (chaotic) . . lrand48 lrand48(3). morse Lorem Ipsum. nybble 0x00 0x0f. objcode (object code) (text segment) stress-ng. parity (parity bit). pink .. (Gardner) (McCartney). . random . rarely1 . rarely0 . rdrand rdrand ( x86) mwc x86. ror32 . text (ASCII) . utf8 UTF-8. zero . --zlib-ops N N bogo bogo 64 K . --zlib-strategy S deflate . . 0 . cB2 lB lB lB c l s s. 0 (Z_DEFAULT_STRATEGY). 1 (Z_FILTERED). 2 (Z_HUFFMAN_ONLY). 3 (Z_RLE). 4 (Z_FIXED). --zlib-stream-bytes S deflate deflate Z_STREAM_END . b k m g . 0 . 0 deflate . n n . Z_STREAM_END . --zlib-window-bits W . ( 9 2^9 = 512 ). 15 . -8-(-15) deflate. 8-15 zlib. 24-31 gzip. 40-47 inflate zlib deflate. (Zombie processes stressor) --zombie N N . 8192 (reap) . ( fork ) (reap) (FIFO) . --zombie-clone clone(2) fork(2) ( ). CAP_SYS_ADMIN (namespaces) cgroup ipc net mount PID mount . --zombie-max N N . N . --zombie-ops N N (bogo). stress-ng --vm 8 --vm-bytes 80% -t 1h . . stress-ng --vm 50% -t 1h CPU . stress-ng --vm 200% -t 1h CPU . stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 1G --timeout 60s cpu io vm . stress-ng --iomix 2 --iomix-bytes 10% -t 10m I/O . . stress-ng --with cpu,matrix,vecmath,fp --seq 8 -t 1m cpu matrix vecmath fp . stress-ng --trig 25% --fp 50% --fma 25% -t 5m --verify CPU (floating point) CPU fused-multiple-add CPU . stress-ng --with cpu,matrix,vecmath,fp --permute 5 -t 10s cpu matrix vecmath fp . stress-ng --cyclic 1 --cyclic-dist 2500 --cyclic-method clock_ns --cyclic-prio 100 --cyclic-sleep 10000 --hdd 0 -t 1m (real time) hdd. . . : CAP_SYS_NICE . stress-ng --cpu 8 --cpu-ops 800000 cpu bogo. stress-ng --sequential 2 --timeout 2m --metrics . stress-ng --cpu 4 --cpu-method fft --cpu-ops 10000 --metrics-brief cpu FFT bogo FFT. stress-ng --cpu -1 --cpu-method all -t 1h --cpu-load 90 cpu CPU CPU CPU . stress-ng --cpu 0 --cpu-method all -t 20m cpu CPU CPU . stress-ng --all 4 --timeout 5m . stress-ng --random 64 . stress-ng --cpu 64 --cpu-method all --verify -t 10m --metrics-brief cpu bogo . stress-ng --sequential -1 -t 10m CPU . stress-ng --sequential 8 --class io -t 5m --times io . stress-ng --class io\? io. sudo stress-ng --class scheduler --seq 0 -t 1m --taskset-random --progress --klog-check (scheduler) CPU CPU . stress-ng --all -1 --maximize --aggressive ( CPU ) ( ) / . stress-ng --all 8 --with cpu,hash,nop,vm --timeout 1m cpu hash nop vm . stress-ng --seq 8 --with cpu,hash,nop,vm --timeout 1m --progress cpu hash nop vm . stress-ng --random 32 -x numa,hdd,key numa hdd key. stress-ng --sequential 4 --class vm --exclude bigheap,brk,stack VM bigheap brk stack. stress-ng --taskset 0,2-3 --cpu 3 CPU (pin) CPU . stress-ng --taskset odd --cpu 32 CPU (pin) CPU . stress-ng --exercise-feature memory-copy,memory-cmp --seq 1 -t 10 ( ) . stress-ng --exercise-syscall select,poll --all 4 -t 60 select poll . stress-ng --exercise-syscall \? ..SH " (EXIT STATUS)" 0 . 1 (stressor harness) stress-ng ( ). 2 (stressor) . 3 ENOMEM ( ) ENOSPC ( ) . 4 . 5 ( ). 6 exit(2) . 7 bogo ops . bogo-ops OOM . . (BUGS) : https://github.com/ColinIanKing/stress-ng/issues - stress-ng . (SEE ALSO) cpuburn(1), perf(1), stress(1), taskset(1) https://github.com/ColinIanKing/stress-ng/blob/master/README.md (AUTHORS) stress-ng Colin Ian King (clean room) stress Amos Waterland . stress-ng. README.md . (SPONSOR) stress-ng . ( ) . : https://github.com/sponsors/ColinIanKing (NOTES) SIGALRM SIGINT SIGHUP stress-ng (stressor) . SIGUSR2 stress-ng (load average) . cpu io vm hdd stress-ng stress . bogo . (COPYRIGHT) (C) 2013-2021 Canonical Ltd (C) 2021-2026 Colin Ian King. . . 14 August 2026 STRESS-NG(1)