Re: PLEASE TEST: IPI deadlock avoidance patch

From: Brian Fundakowski Feldman <green_at_freebsd.org>
Date: Mon, 23 Aug 2004 11:41:19 -0400
On Sun, Aug 22, 2004 at 12:05:39PM -0700, Doug White wrote:
> Hey folks,
> 
> If you have a reasonably fast i386 or amd64 multiprocessor and/or
> hyperthreading machine and are experiencing reproducible hangs during -j
> buildwords and other highly parallel operations, please try this patch:
> 
> http://people.freebsd.org/~dwhite/smp_rv_mtx.patch
> 
> This patch avoids a deadlock between the smp_rendezvous() mechanism and
> TLB shootdowns via pmap by forcing them to share a mutex.  The patch has
> been tested on several multiproc Xeon systems and a dual Opteron I have
> here and is stable, but a couple of more eyeballs and varied loads
> wouldn't hurt since this will be going into RELENG_5.
> 
> If there's anything glaringly wrong from a style point of view, let me
> know too.
> 
> I plan on committing this late Monday or Tuesday, barring any serious
> problems.
> 
> Thanks to alc for the nudge on the solution and rwatson for staying up
> late and testing it on his hardware.

I couldn't even run portupgrade without a hard hang on my Athlon!

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green_at_FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\
Received on Mon Aug 23 2004 - 13:41:20 UTC

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