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From: "Cyrille Lefevre" <clefevre-lists@9online.fr>
To: "Scott Long" <scottl@freebsd.org>,
	"Dan Nelson" <dnelson@allantgroup.com>
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Date: Tue, 18 May 2004 09:50:23 +0200
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cc: freebsd-current@freebsd.org
cc: Michael Hamburg <hamburg@fas.harvard.edu>
Subject: Re: fsck in -current
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"Scott Long" <scottl@freebsd.org> wrote:

> Dan Nelson wrote:
[snip]
> > Fsck takes very little CPU; it's almost all disk I/O, and bgfsck tries
> > to throttle its load if it thinks that there's too much disk load.
> 
> Actually, bgfsck unconditionally inserts a delay into every 8th i/o
> operation to try to keep from saturating the disks.  Unfortunately
> this isn't terribly sophisticated and it results in bgfsck taking
> an eternity whether the system is idle, loaded, or reniced.


doesn't the delay be related to the load average or to ki_pctcpu (sys/user.h) ?
say, allow bgfsck to eat up to 5 or 10 % of CPU usage ?
see getpcpu() in bin/ps/print.c for details.

Cyrille Lefevre.
-- 
home: mailto:cyrille.lefevre@laposte.net