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Date: Tue, 10 Feb 2009 11:01:25 +0700
From: Eugene Grosbein <eugen@kuzbass.ru>
To: Kostik Belousov <kostikbel@gmail.com>
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	<20090209214822.GH9427@deviant.kiev.zoral.com.ua>
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Cc: stable@freebsd.org
Subject: Re: sysctl lock in RELENG_6
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On Mon, Feb 09, 2009 at 11:48:22PM +0200, Kostik Belousov wrote:

> > I've digged commit logs a bit and found this change MFC'd to RELENG_7
> > but not RELENG_6:
> > 
> > http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/kern_sysctl.c#rev1.177.6.2
> > 
> > It seems RELENG_6 needs this too, doesn't it?
> > I'm going to merge the change to RELENG_6 and give it a try.
> 
> Yes, please give it a try. In fact, it was quite specific situation
> that I observed and produced a fix for. You need execing process that
> needs to grab Giant, e.g. due to image being located on !MPSAFE fs, and
> simultaneous sysctl issued that inspects this process.

Well, my 6.3-STABLE locked very often (sometimes every hour).
Yesterday I've upgraded it to 6.4-STABLE, applied 1.177.2.1 of the file
to sources, rebuilt NanoBSD image and ran it. It has not locked yet.

Btw, root filesystem here is UFS2 without softupdates mounted read-only
but /etc and /var are md(4) (devfs is mounted too).

Eugene Grosbein