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Re: [Xen-devel] [PATCH] xen/sched: fix locking in sched_tick_[suspend|resume]()


  • To: Juergen Gross <jgross@xxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: George Dunlap <george.dunlap@xxxxxxxxxx>
  • Date: Fri, 4 Oct 2019 15:08:56 +0100
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  • Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>, Dario Faggioli <dfaggioli@xxxxxxxx>
  • Delivery-date: Fri, 04 Oct 2019 14:09:02 +0000
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  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
  • Openpgp: preference=signencrypt

On 10/4/19 7:40 AM, Juergen Gross wrote:
> sched_tick_suspend() and sched_tick_resume() should not call the
> scheduler specific timer handlers in case the cpu they are running on
> is just being moved to or from a cpupool.
> 
> Use a new percpu lock for that purpose.

Is there a reason we can't use the pcpu_schedule_lock() instead of
introducing a new one?  Sorry if this is obvious, but it's been a while
since I poked around this code.

 -George

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