diff options
Diffstat (limited to 'man2/posix_fadvise.2')
| -rw-r--r-- | man2/posix_fadvise.2 | 75 |
1 files changed, 39 insertions, 36 deletions
diff --git a/man2/posix_fadvise.2 b/man2/posix_fadvise.2 index 57c65c8107..64ba39227c 100644 --- a/man2/posix_fadvise.2 +++ b/man2/posix_fadvise.2 @@ -127,47 +127,11 @@ Linux returned .B EINVAL in this case.) .SH VERSIONS -Kernel support first appeared in Linux 2.5.60; -the underlying system call is called -.BR fadvise64 (). -.\" of fadvise64_64() -Library support has been provided since glibc 2.2, -via the wrapper function -.BR posix_fadvise (). -.PP -Since Linux 3.18, -.\" commit d3ac21cacc24790eb45d735769f35753f5b56ceb -support for the underlying system call is optional, -depending on the setting of the -.B CONFIG_ADVISE_SYSCALLS -configuration option. -.SH STANDARDS -POSIX.1-2001, POSIX.1-2008. -Note that the type of the -.I len -argument was changed from -.I size_t -to -.I off_t -in POSIX.1-2001 TC1. -.SH NOTES Under Linux, \fBPOSIX_FADV_NORMAL\fP sets the readahead window to the default size for the backing device; \fBPOSIX_FADV_SEQUENTIAL\fP doubles this size, and \fBPOSIX_FADV_RANDOM\fP disables file readahead entirely. These changes affect the entire file, not just the specified region (but other open file handles to the same file are unaffected). -.PP -The contents of the kernel buffer cache can be cleared via the -.I /proc/sys/vm/drop_caches -interface described in -.BR proc (5). -.PP -One can obtain a snapshot of which pages of a file are resident -in the buffer cache by opening a file, mapping it with -.BR mmap (2), -and then applying -.BR mincore (2) -to the mapping. .SS C library/kernel differences The name of the wrapper function in the C library is .BR posix_fadvise (). @@ -210,6 +174,45 @@ hidden from applications by the glibc .BR posix_fadvise () wrapper function, which invokes the appropriate architecture-specific system call. +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001. +.PP +Kernel support first appeared in Linux 2.5.60; +the underlying system call is called +.BR fadvise64 (). +.\" of fadvise64_64() +Library support has been provided since glibc 2.2, +via the wrapper function +.BR posix_fadvise (). +.PP +Since Linux 3.18, +.\" commit d3ac21cacc24790eb45d735769f35753f5b56ceb +support for the underlying system call is optional, +depending on the setting of the +.B CONFIG_ADVISE_SYSCALLS +configuration option. +.PP +The type of the +.I len +argument was changed from +.I size_t +to +.I off_t +in POSIX.1-2001 TC1. +.SH NOTES +The contents of the kernel buffer cache can be cleared via the +.I /proc/sys/vm/drop_caches +interface described in +.BR proc (5). +.PP +One can obtain a snapshot of which pages of a file are resident +in the buffer cache by opening a file, mapping it with +.BR mmap (2), +and then applying +.BR mincore (2) +to the mapping. .SH BUGS Before Linux 2.6.6, if .I len |