From: Ingo Molnar <mingo@elte.hu>
To: Nathan Lynch <nathanl@austin.ibm.com>
Cc: akpm@osdl.org, lkml <linux-kernel@vger.kernel.org>,
Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [PATCH] cpu hotplug fixes for dependent_sleeper and wake_sleeping_dependent
Date: Mon, 30 Aug 2004 15:29:25 +0200 [thread overview]
Message-ID: <20040830132925.GA1531@elte.hu> (raw)
In-Reply-To: <1093858876.11274.50.camel@biclops.private.network>
* Nathan Lynch <nathanl@austin.ibm.com> wrote:
> To recap, offlining a cpu with current bk results in the "Aiee,
> killing interrupt handler!" panic from do_exit(). This seems to be
> triggered only with CONFIG_PREEMPT and CONFIG_SCHED_SMT both enabled.
> I believe the problem is that when do_stop() calls schedule(),
> dependent_sleeper() drops the "offline" cpu's rq->lock and never
> reacquires it.
>
> The following seems to work (tested on ppc64). Is there a better way?
> - if (!(sd->flags & SD_SHARE_CPUPOWER))
> + if (!(sd->flags & SD_SHARE_CPUPOWER) || cpu_is_offline(this_cpu))
> + if (!(sd->flags & SD_SHARE_CPUPOWER) || cpu_is_offline(this_cpu))
it would really be nice to do this without any runtime overhead. Rusty?
Ingo
next prev parent reply other threads:[~2004-08-30 13:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-30 9:41 [PATCH] cpu hotplug fixes for dependent_sleeper and wake_sleeping_dependent Nathan Lynch
2004-08-30 13:29 ` Ingo Molnar [this message]
2004-09-01 23:25 ` Rusty Russell
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