[src/netbsd-1-5]: src/lib/libc/sys pullup rev. 1.8 from trunk (approved by th...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/94c267c11cec
branches:  netbsd-1-5
changeset: 489704:94c267c11cec
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Sat Oct 07 07:39:59 2000 +0000

description:
pullup rev. 1.8 from trunk (approved by thorpej):
remove reference to update(8), it no longer exists
add a few words about ioflush instead

diffstat:

 lib/libc/sys/sync.2 |  21 +++++++++++----------
 1 files changed, 11 insertions(+), 10 deletions(-)

diffs (42 lines):

diff -r 21b2702e4d62 -r 94c267c11cec lib/libc/sys/sync.2
--- a/lib/libc/sys/sync.2       Sat Oct 07 07:37:39 2000 +0000
+++ b/lib/libc/sys/sync.2       Sat Oct 07 07:39:59 2000 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: sync.2,v 1.7 1999/12/02 21:42:40 kleink Exp $
+.\"    $NetBSD: sync.2,v 1.7.4.1 2000/10/07 07:39:59 jdolecek Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -52,13 +52,15 @@
 in the block buffer cache out
 to disk. The kernel keeps this information in core to reduce
 the number of disk I/O transfers required by the system.
-As information in the cache is lost after a system crash a
-.Fn sync
-call is issued
-frequently
-by the user process
-.Xr update 8
-(about every 30 seconds). 
+As information in the cache is lost after a system crash,
+kernel thread
+.Nm ioflush
+ensures that dirty buffers are synced to disk
+eventually. By default, a dirty buffer is synced after 30 seconds,
+but some filesystems exploit
+.Nm ioflush
+features to sync directory data and metadata faster
+(after 15 and 10 seconds, respectively).
 .Pp
 The function
 .Xr fsync 2
@@ -66,8 +68,7 @@
 attributes.
 .Sh SEE ALSO
 .Xr fsync 2 ,
-.Xr sync 8 ,
-.Xr update 8
+.Xr sync 8
 .Sh BUGS
 .Fn sync
 may return before the buffers are completely flushed.