System load as crash factor with preemption???

From: Conrad J. Sabatier <conrads_at_cox.net>
Date: Wed, 04 Aug 2004 11:56:53 -0500 (CDT)
On 04-Aug-2004 Kenneth Stailey wrote:
> http://www.freebsd.org/releases/5.3R/todo.html
> 
> << Problems persist with crashes and hangs under heavy load,
> especially under SMP. The recent introduction of full-scale
> preemption exasperated the problem, though it has been mitigated by a
> recently committed hack.  Speculation on the source of the problem
> seems to center around races in critical section and spinlock
> handling and nesting. This needs to be driven to root cause and
> fixed in order for 5.3 to be considered STABLE. >>

One thing I've been wondering about in all the postings I've seen re:
the preemption-related crashes: reference is made repeatedly to crashes
occurring under heavy load, yet my box (AMD Athlon 64, single-processor)
was crashing under practically no load at all.

With the no-preemption hack, the box has been quite stable, by the way.

Also, my other machine, an AMD Athlon (32-bit), single-processor,
running an i386 build, never experienced any crashes, yet it bears much
more load most of the time than the 64-bit box, as I use it as my
gateway, cvsup daemon, NFS server, etc, etc.

Just makes me question how much of a factor load really played in this
problem, and thought it might be worth mentioning.

-- 
Conrad J. Sabatier <conrads_at_cox.net> -- "In Unix veritas"
Received on Wed Aug 04 2004 - 14:56:55 UTC

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