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Re: [Xen-devel] linux: {start, stop}_hz_timer() not really affecting per

To: Jan Beulich <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] linux: {start, stop}_hz_timer() not really affecting periodic timer?
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Wed, 16 Jan 2008 16:46:26 +0000
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On 16/1/08 16:36, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:

>> If the time is in the past then the singleshot timer will fire immediately.
>> So you'll take a slower path than necessary, but the code as-is will work
>> fine.
> 
> Immediately would mean to me that it would fire on the return path
> from VCPUOP_set_singleshot_timer, so HYPERVISOR_block() would
> not (necessarily) find any pending events and hence block when it
> shouldn't. Or am I missing some magic by which this is being avoided?

The function should only be called with interrupts disabled.

 -- Keir



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