Date: Mon, 28 Sep 2009 16:59:47 +0000 (UTC) From: Xin LI <delphij@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/lib/libc/sys fcntl.2 src/sys/kern kern_descrip.c vfs_vnops.c src/sys/sys fcntl.h Message-ID: <200909281702.n8SH2Njl017331@repoman.freebsd.org>
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delphij 2009-09-28 16:59:47 UTC
FreeBSD src repository
Modified files:
lib/libc/sys fcntl.2
sys/kern kern_descrip.c vfs_vnops.c
sys/sys fcntl.h
Log:
SVN rev 197579 on 2009-09-28 16:59:47Z by delphij
Add two new fcntls to enable/disable read-ahead:
- F_READAHEAD: specify the amount for sequential access. The amount is
specified in bytes and is rounded up to nearest block size.
- F_RDAHEAD: Darwin compatible version that use 128KB as the sequential
access size.
A third argument of zero disables the read-ahead behavior.
Please note that the read-ahead amount is also constrainted by sysctl
variable, vfs.read_max, which may need to be raised in order to better
utilize this feature.
Thanks Igor Sysoev for proposing the feature and submitting the original
version, and kib@ for his valuable comments.
Submitted by: Igor Sysoev <is rambler-co ru>
Reviewed by: kib@
MFC after: 1 month
Revision Changes Path
1.48 +17 -1 src/lib/libc/sys/fcntl.2
1.358 +44 -0 src/sys/kern/kern_descrip.c
1.289 +3 -0 src/sys/kern/vfs_vnops.c
1.26 +7 -2 src/sys/sys/fcntl.h
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