RE: [Xen-devel] Re: [PATCH] CPUIDLE: shorten hpet spin_lock holding time

["Wei, Gang" <gang.wei@xxxxxxxxx>]

On Thursday, 2010-4-22 4:23 PM, Keir Fraser wrote:
> On 22/04/2010 09:19, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:
>> How about the attached patch? It MWAITs on a completely new flag
>> field, avoiding the IPI-avoidance semantics of softirq_pending. It
>> also folds in your patch. It also does wakeup-waiting checks on
>> timer_deadline_start, that being the field that initiates wakeup via
>> the MONITORed memory region. 
> 
> ...If you do think it looks okay, could you also test it out on
> relevant hardware? :-)

Did some modification to this patch -- move the per_cpu mait_wakeup flag into 
irq_cpustat_t to make it __cacheline_aligned, and add check for 
timer_deadline_start==0 (means no timer in queue, it took me quite a lot time 
to find out it is necessary) case. Tested ok.

Jimmy

00-mwait-v2.patch
Description: 00-mwait-v2.patch

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