diff options
Diffstat (limited to 'lib/libc')
-rw-r--r-- | lib/libc/sys/Makefile.inc | 3 | ||||
-rw-r--r-- | lib/libc/sys/Symbol.map | 4 | ||||
-rw-r--r-- | lib/libc/sys/madvise.2 | 3 | ||||
-rw-r--r-- | lib/libc/sys/posix_fadvise.2 | 139 |
4 files changed, 147 insertions, 2 deletions
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc index fe5061d..6da6a00 100644 --- a/lib/libc/sys/Makefile.inc +++ b/lib/libc/sys/Makefile.inc @@ -96,7 +96,8 @@ MAN+= abort2.2 accept.2 access.2 acct.2 adjtime.2 \ mq_setattr.2 \ msgctl.2 msgget.2 msgrcv.2 msgsnd.2 \ msync.2 munmap.2 nanosleep.2 nfssvc.2 ntp_adjtime.2 open.2 \ - pathconf.2 pdfork.2 pipe.2 poll.2 posix_fallocate.2 posix_openpt.2 profil.2 \ + pathconf.2 pdfork.2 pipe.2 poll.2 posix_fadvise.2 posix_fallocate.2 \ + posix_openpt.2 profil.2 \ pselect.2 ptrace.2 quotactl.2 \ read.2 readlink.2 reboot.2 recv.2 rename.2 revoke.2 rfork.2 rmdir.2 \ rtprio.2 diff --git a/lib/libc/sys/Symbol.map b/lib/libc/sys/Symbol.map index 095751a..d0c0c94 100644 --- a/lib/libc/sys/Symbol.map +++ b/lib/libc/sys/Symbol.map @@ -378,6 +378,10 @@ FBSD_1.2 { setloginclass; }; +FBSD_1.3 { + posix_fadvise; +}; + FBSDprivate_1.0 { ___acl_aclcheck_fd; __sys___acl_aclcheck_fd; diff --git a/lib/libc/sys/madvise.2 b/lib/libc/sys/madvise.2 index 48f0e5a..b5ea6b2 100644 --- a/lib/libc/sys/madvise.2 +++ b/lib/libc/sys/madvise.2 @@ -169,7 +169,8 @@ was specified and the process does not have superuser privileges. .Xr mincore 2 , .Xr mprotect 2 , .Xr msync 2 , -.Xr munmap 2 +.Xr munmap 2 , +.Xr posix_fadvise 2 .Sh STANDARDS The .Fn posix_madvise diff --git a/lib/libc/sys/posix_fadvise.2 b/lib/libc/sys/posix_fadvise.2 new file mode 100644 index 0000000..bdf321f --- /dev/null +++ b/lib/libc/sys/posix_fadvise.2 @@ -0,0 +1,139 @@ +.\" Copyright (c) 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)madvise.2 8.1 (Berkeley) 6/9/93 +.\" $FreeBSD$ +.\" +.Dd October 26, 2011 +.Dt POSIX_FADVISE 2 +.Os +.Sh NAME +.Nm posix_fadvise +.Nd give advice about use of file data +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In fcntl.h +.Ft int +.Fn posix_fadvise "int fd" "off_t offset" "off_t len" "int advice" +.Sh DESCRIPTION +The +.Fn posix_fadvise +system call +allows a process to describe to the system its data access behavior for an +open file descriptor +.Fa fd . +The advice covers the data starting at offset +.Fa offset +and continuing for +.Fa len +bytes. +If +.Fa len +is zero, +all data from +.Fa offset +to the end of the file is covered. +.Pp +The behavior is specified by the +.Fa advice +parameter and may be one of: +.Bl -tag -width POSIX_FADV_SEQUENTIAL +.It Dv POSIX_FADV_NORMAL +Tells the system to revert to the default data access behavior. +.It Dv POSIX_FADV_RANDOM +Is a hint that file data will be accessed randomly, +and prefetching is likely not advantageous. +.It Dv POSIX_FADV_SEQUENTIAL +Tells the system that file data will be accessed sequentially. +This currently does nothing as the default behavior uses heuristics to +detect sequential behavior. +.It Dv POSIX_FADV_WILLNEED +Tells the system that the specified data will be accessed in the near future. +The system may initiate an asychronous read of the data if it is not already +present in memory. +.It Dv POSIX_FADV_DONTNEED +Tells the system that the specified data will not be accessed in the near +future. +The system may decrease the in-memory priority of clean data within the +specified range and future access to this data may require a read operation. +.It Dv POSIX_FADV_NOREUSE +Tells the system that the specified data will only be accessed once and +then not reused. +Accesses to data within the specified range are treated as if the file +descriptor has the +.Dv O_DIRECT +flag enabled. +.El +.Pp +.Sh RETURN VALUES +.Rv -std posix_fadvise +.Sh ERRORS +The +.Fn posix_fadvise +system call will fail if: +.Bl -tag -width Er +.It Bq Er EBADF +The +.Fa fd +argument is not a valid file descriptor. +.It Bq Er EINVAL +The +.Fa advice +argument is not valid. +.It Bq Er EINVAL +The +.Fa offset +or +.Fa len +arguments are negative, +or +.Fa offset ++ +.Fa len +is greater than the maximum file size. +.It Bq Er ENODEV +The +.Fa fd +argument does not refer to a regular file. +.It Bq Er ESPIPE +The +.Fa fd +argument is associated with a pipe or FIFO. +.El +.Sh SEE ALSO +.Xr madvise 2 +.Sh STANDARDS +The +.Fn posix_fadvise +interface conforms to +.St -p1003.1-2001 . +.Sh HISTORY +The +.Fn posix_fadvise +system call first appeared in +.Fx 10.0 . |