From: Peter Zijlstra <peterz@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Subject: Re: needed lru_add_drain_all() change
Date: Wed, 27 Jun 2012 14:04:23 +0200 [thread overview]
Message-ID: <1340798663.10063.36.camel@twins> (raw)
In-Reply-To: <20120626143703.396d6d66.akpm@linux-foundation.org>
On Tue, 2012-06-26 at 14:37 -0700, Andrew Morton wrote:
> lru_add_drain_all() uses schedule_on_each_cpu(). But
> schedule_on_each_cpu() hangs if a realtime thread is spinning, pinned
> to a CPU. There's no intention to change the scheduler behaviour, so
> I
> think we should remove schedule_on_each_cpu() from the kernel.
>
Anything that uses a per-cpu workqueue and waits on work from another
cpu is vulnerable too. This would include things like padata, crypto and
possibly others.
ksoftirqd is vulnerable too, if it were preempted while handling a
softirq, all of softirq handling will be out the window for that cpu.
infiniband/hw/ehca would likely malfunction as well, since it has
per-cpu threads.
FIFO is dangerous, don't do stupid things :-)
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next prev parent reply other threads:[~2012-06-27 12:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-26 21:37 needed lru_add_drain_all() change Andrew Morton
2012-06-27 0:55 ` Minchan Kim
2012-06-27 1:15 ` Andrew Morton
2012-06-27 1:20 ` Minchan Kim
2012-06-27 1:29 ` Andrew Morton
2012-06-27 2:09 ` Minchan Kim
2012-06-27 5:12 ` Andrew Morton
2012-06-27 5:41 ` Minchan Kim
2012-06-27 5:55 ` Andrew Morton
2012-06-27 6:33 ` Minchan Kim
2012-06-27 6:41 ` Andrew Morton
2012-06-27 10:27 ` Peter Zijlstra
2012-06-27 6:46 ` Andrew Morton
2012-06-27 10:31 ` Peter Zijlstra
2012-06-27 12:04 ` Peter Zijlstra [this message]
2012-06-28 6:23 ` KOSAKI Motohiro
2012-06-29 3:47 ` Kamezawa Hiroyuki
2012-06-28 7:43 ` Kamezawa Hiroyuki
2012-06-28 23:42 ` Minchan Kim
2012-06-29 3:24 ` Kamezawa Hiroyuki
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