Messages in this thread | | | Date | Wed, 27 Jul 2011 23:52:18 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: migrate_disable() race with cpu hotplug? |
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On Tue, 26 Jul 2011, Yong Zhang wrote:
> When reading the code, I'm afraid there is a race between migrate_disable() > and cpu hotplug. A scenario will like below: > > CPU0 CPU1 > _cpu_down(); > cpu_unplug_begin(); > wait_for_completion() > sync_unplug_thread(); > complete(); > race_window? /* > * migrate_disable() will > * not take effect since > * hotplug is in progress > */
Rightfully so. The caller will just block on the cpu_hotplug.lock mutex until the unplug operation will be done.
Thanks,
tglx
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