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From: peterz@infradead.org (Peter Zijlstra)
To: linux-snps-arc@lists.infradead.org
Subject: Patch "asm-generic/bitops/lock.h: Rewrite using atomic_fetch_" causes kernel crash
Date: Thu, 30 Aug 2018 19:15:10 +0200	[thread overview]
Message-ID: <20180830171510.GQ24082@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1535640375.4465.68.camel@synopsys.com>

On Thu, Aug 30, 2018@02:46:16PM +0000, Eugeniy Paltsev wrote:
> On Thu, 2018-08-30@16:17 +0200, Peter Zijlstra wrote:
> > On Thu, Aug 30, 2018@11:53:17AM +0000, Eugeniy Paltsev wrote:
> > > I can see crashes with LLSC enabled in both SMP running on 4 cores
> > > and SMP running on 1 core.
> > 
> > So you're running on LL/SC enabled hardware; that would make Will's
> > patch irrelevant (although still a good idea for the hardware that does
> > care about that spinlocked atomic crud).
> > 
> > Does something like the below cure things? That would confirm the
> > suggestion that the change to __clear_bit_unlock() is the curprit.
> 
> I tested it - this doesn't change anything, the problem still reproduces.

OK, 'good' :-)

> I'll test it with last Will fix.

Yes, that missing "bnz 1b" is very very suspect.

  reply	other threads:[~2018-08-30 17:15 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-29 18:33 Patch "asm-generic/bitops/lock.h: Rewrite using atomic_fetch_" causes kernel crash Eugeniy Paltsev
2018-08-29 21:16 ` Vineet Gupta
2018-08-30  9:35   ` Will Deacon
2018-08-30  9:44   ` Peter Zijlstra
2018-08-30  9:51     ` Will Deacon
2018-08-30 11:53       ` Eugeniy Paltsev
2018-08-30 13:57         ` Will Deacon
2018-08-30 14:17         ` Peter Zijlstra
2018-08-30 14:23           ` Will Deacon
2018-08-30 14:29             ` Peter Zijlstra
2018-08-30 14:43               ` Peter Zijlstra
2020-04-14  1:19                 ` Vineet Gupta
2018-08-30 20:31               ` Vineet Gupta
2018-08-30 20:45                 ` Peter Zijlstra
2018-08-31  0:30                   ` Vineet Gupta
2018-08-31  9:53                     ` Will Deacon
2018-08-30 14:46           ` Eugeniy Paltsev
2018-08-30 17:15             ` Peter Zijlstra [this message]
2018-08-31  0:42       ` Vineet Gupta
2018-08-31  0:29     ` __clear_bit_lock to use atomic clear_bit (was Re: Patch "asm-generic/bitops/lock.h) Vineet Gupta
2018-08-31  7:24       ` Peter Zijlstra

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