sysctl lock in RELENG_6

[Kostik Belousov]

On Mon, Feb 09, 2009 at 10:59:38AM +0700, Eugene Grosbein wrote:
> Hi!
> 
> I've RELENG_6 system controlling local PBX through RS-232 port, sio(4).
> It also runs syslogd, cron, sshd, bsnmpd and sendmail for outgoing reports.
> 
> It locks very often: it answers to pings but PBX controlling software stops
> responding, local and remote login attempts hang due to 'login' process
> stuck in 'sysctl lock' state. Local consoles do switch with 'Alt-Fn'
> and DDB works. It shows that sendmail is in 'sysctl lock' state too.
> 
> This is NanoBSD installation running from IDE flash, it's swapless
> but I think I could manage to obtain crashdump if there is an interest of it.
> 
> 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.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20090209/a879c297/attachment.pgp