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RE: [Xen-devel] [PATCH 2/4] CPUIDLE: Avoid remnant LAPIC timer intrwhile

To: "Wei, Gang" <gang.wei@xxxxxxxxx>, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH 2/4] CPUIDLE: Avoid remnant LAPIC timer intrwhile force hpetbroadcast
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Wed, 10 Sep 2008 22:51:31 +0800
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Thread-topic: [Xen-devel] [PATCH 2/4] CPUIDLE: Avoid remnant LAPIC timer intrwhile force hpetbroadcast
>From: Wei, Gang
>Sent: 2008年9月10日 22:25
>> It's not clear to me the disable/enable_LAPIC_timer() work 
>is worthwhile for
>> the few timer interrupts it is likely to avoid. The other 
>bit of the patch
>> is a good bugfix though. I've taken just the latter part.
>Thanks for accept most of these patches. As to 
>disable/enable_LAPIC_timer(), I add them because some 
>platforms require the LAPIC timer intr being disabled before 
>entering C3, otherwise there may be some unexpected things. As 
>a reference, Linux kernel always do so.

Also this is conceptually clearer, as at given time we only
want one clock source to drive timers. It'd make little sense
to have APIC timer freely counting down to trigger spurious
interrupt when HPET/PIT already plays the role before APIC 
timer is reprogrammed upon C3 exit. :-)


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