posix_fadvise(2)              System Calls Manual             posix_fadvise(2)

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       posix_fadvise - <?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
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       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?> C (libc, -lc)

<?><?><?><?><?><?><?><?><?>
       #include <fcntl.h>

       int posix_fadvise(int fd, off_t offset, off_t size, int advice);

   <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
   <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?><?> glibc
   (<?><?>. feature_test_macros(7)):

       posix_fadvise():
           _POSIX_C_SOURCE >= 200112L

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       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> posix_fadvise() <?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?>
       <?><?><?><?><?> <?><?><?><?><?><?> <?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?>, <?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?><?><?>.

       The advice applies to a (not necessarily existent) region starting at
       offset and extending for size bytes (or until the end of the file if
       size is 0)  within the file referred to by fd.  The advice is not
       binding; it merely constitutes an expectation on behalf of the
       application.

       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> advice:

       POSIX_FADV_NORMAL
              <?><?><?><?><?><?><?><?><?>, <?><?><?>
              <?><?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?><?>
              <?><?><?> <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>.
              <?><?><?><?> <?><?> <?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>, <?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?>
              <?><?><?><?><?><?><?><?><?>.

       POSIX_FADV_SEQUENTIAL
              <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?> (<?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?>
              <?><?><?><?><?><?><?> <?><?><?><?><?><?><?>).

       POSIX_FADV_RANDOM
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?><?> <?>
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>.

       POSIX_FADV_NOREUSE
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?>
              <?><?><?>.

              Before Linux 2.6.18, POSIX_FADV_NOREUSE had the same semantics
              as POSIX_FADV_WILLNEED.  This was probably a bug; from Linux
              2.6.18 until Linux 6.2 this flag was a no-op.  Since Linux 6.3,
              POSIX_FADV_NOREUSE signals that the kernel page replacement
              algorithm can ignore access to mapped page cache marked by this
              flag.  This is useful, for example, while streaming large files.

       POSIX_FADV_WILLNEED
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?>.

              <?><?><?> POSIX_FADV_WILLNEED <?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
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              <?><?><?><?><?><?><?><?> <?><?><?><?>. <?><?><?><?><?>
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              <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?><?><?> <?><?>
              <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?> (<?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?><?><?><?><?>, <?> <?><?><?><?><?><?>,
              <?><?><?><?><?><?>, <?> <?><?> <?><?><?><?><?><?>
              <?><?><?><?><?>).

       POSIX_FADV_DONTNEED
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?>
              <?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?>
              <?><?><?><?><?><?> <?><?><?><?><?><?><?>.

              <?><?><?> <?><?><?><?><?><?><?><?> POSIX_FADV_DONTNEED
              <?><?><?><?><?> <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>,
              <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?>. <?><?><?> <?><?><?><?><?><?><?>,
              <?><?><?><?><?><?><?><?>, <?><?><?> <?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
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              <?><?><?> <?><?><?> <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
              <?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>.

              Requests to discard partial pages are ignored.  It is preferable
              to preserve needed data than discard unneeded data.  If the
              application requires that data be considered for discarding,
              then offset and size must be page-aligned.

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              <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> (dirty)
              <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?>, <?><?> <?><?><?> <?><?>
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              <?><?><?><?><?><?><?><?><?><?>
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              <?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>.
              <?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>,
              <?><?> <?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?> fsync(2) <?><?><?> fdatasync(2).

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       <?><?><?> <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> 0. <?> <?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?>.

<?><?><?><?><?><?>
       EBADF  <?><?><?><?><?><?><?><?> fd <?><?> <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?>.

       EINVAL <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> advice.

       ESPIPE The specified file descriptor refers to a pipe or FIFO.  (ESPIPE
              is the error specified by POSIX, but before Linux 2.6.16, Linux
              returned EINVAL in this case.)

<?><?><?><?><?><?>
       Under Linux, POSIX_FADV_NORMAL sets the readahead window to the default
       size for the backing device; POSIX_FADV_SEQUENTIAL doubles this size,
       and POSIX_FADV_RANDOM disables file readahead entirely.
       POSIX_FADV_NOREUSE does not modify the readahead window size.  These
       changes affect the entire file, not just the specified region (but
       other open file handles to the same file are unaffected).

   <?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> C
       <?> <?><?><?><?><?>
       The name of the wrapper function in the C library is posix_fadvise().
       The underlying system call is called fadvise64()  (or, on some
       architectures, fadvise64_64()); the difference between the two is that
       the former system call assumes that the type of the size argument is
       size_t, while the latter expects loff_t there.

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       <?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?><?> (<?><?><?><?><?><?><?><?><?><?><?> <?>
       syscall(2)). <?><?> <?><?><?><?><?>
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       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>
       posix_fadvise() <?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> fd <?> offset. <?><?><?><?><?><?><?>
       <?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
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       <?><?><?><?><?><?><?><?><?><?>, <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?> <?>
       posix_fadvise().

       <?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?> <?> Linux 2.6.14, <?>
       ARM <?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?>:

           long arm_fadvise64_64(int fd, int advice,
                                 loff_t offset, loff_t size);

       <?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?>,
       <?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> glibc posix_fadvise(), <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?>.

<?><?><?><?><?><?><?><?><?>
       POSIX.1-2024.

<?><?><?><?><?><?><?>
       POSIX.1-2001.

       Kernel support first appeared in Linux 2.5.60; the underlying system
       call is called fadvise64().  Library support has been provided since
       glibc 2.2, via the wrapper function posix_fadvise().

       <?><?><?><?><?><?><?> <?> Linux 3.18 <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?>, <?><?><?>
       <?><?><?><?><?><?><?> <?><?> <?><?><?><?>, <?><?><?><?><?><?><?> <?><?>
       <?><?><?><?> <?> <?><?><?><?><?><?><?><?><?><?> CONFIG_ADVISE_SYSCALLS.

       The type of the size argument was changed from size_t to off_t in
       POSIX.1-2001 TC1.

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       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?><?><?><?>
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       <?><?><?><?><?> <?><?><?><?><?><?><?><?><?> /proc/sys/vm/drop_caches,
       <?><?><?><?><?><?><?><?><?> <?> proc(5).

       <?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?>, <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?>
       <?><?><?><?>: <?><?><?><?><?><?><?> <?><?><?><?>,
       <?><?><?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?> mmap(2) <?>
       <?><?><?><?><?> <?><?><?><?><?><?><?><?><?> mincore(2) <?>
       <?><?><?><?><?><?><?><?><?><?><?>.

<?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       Before Linux 2.6.6, if size was specified as 0, then this was
       interpreted literally as "zero bytes", rather than as meaning "all
       bytes through to the end of the file".

<?><?><?><?><?><?><?><?> <?><?><?><?><?>
       fincore(1), mincore(2), readahead(2), sync_file_range(2),
       posix_fallocate(3), posix_madvise(3)

<?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?>(<?>) Alexey, Azamat Hackimov
       <azamat.hackimov@gmail.com>, kogamatranslator49 <r.podarov@yandex.ru>,
       Darima Kogan <silverdk99@gmail.com>, Max Is <ismax799@gmail.com>, Yuri
       Kozlov <yuray@komyakino.ru> <?> <?><?><?><?> <?><?><?><?><?><?>
       <pavia00@gmail.com>

       <?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?>; <?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> GNU (GNU General Public License - GPL,
       <https://www.gnu.org/licenses/gpl-3.0.html> <?><?><?><?><?><?> 3
       <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?>) <?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?>, <?><?> <?><?><?> <?><?><?><?><?>-<?><?><?><?>
       <?><?><?><?><?><?><?><?>.

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       <?><?><?><?><?>-<?><?><?><?> <?><?><?><?><?><?> <?>
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       <?><?><?><?><?><?><?><?> <?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?>(<?><?>) <?><?> <?><?><?>(<?><?>)
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       <?><?><?><?><?><?><?><?><?><?><?><?>
       <debian-l10n-russian@lists.debian.org>.

Linux man-pages 6.18   8 <?><?><?><?><?><?><?> 2026 <?>.      posix_fadvise(2)