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    SubjectRe: [PATCH 01/21] workqueue: fix race condition in schedule_on_each_cpu()
    On 11/17/2009 01:04 AM, Frederic Weisbecker wrote:
    > On Tue, Nov 17, 2009 at 02:15:06AM +0900, Tejun Heo wrote:
    >
    >> Commit 65a64464349883891e21e74af16c05d6e1eeb4e9 which allows
    >> schedule_on_each_cpu() to be called from keventd added a race
    >> condition. schedule_on_each_cpu() may race with cpu hotplug and end
    >> up executing the function twice on a cpu.
    >>
    >> Fix it by moving direct execution into the section protected with
    >> get/put_online_cpus(). While at it, update code such that direct
    >> execution is done after works have been scheduled for all other cpus
    >> and drop unnecessary cpu != orig test from flush loop.
    >>
    >> Signed-off-by: Tejun Heo<tj@kernel.org>
    >> Cc: Andi Kleen<ak@linux.intel.com>
    >> Cc: Oleg Nesterov<oleg@redhat.com>
    >> ---
    >>
    >
    > Shouldn't this patch go to .32 ?
    > This looks like an important fix.
    >

    Is anything using preeempt notifier on affected architectures?

    --
    Do not meddle in the internals of kernels, for they are subtle and quick to panic.



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