Xen project Mailing List

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

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>

From: "Wei, Gang" <gang.wei@xxxxxxxxx>

Date: Thu, 29 Apr 2010 19:14:59 +0800

Accept-language: zh-CN, en-US

Acceptlanguage: zh-CN, en-US

Cc:

Delivery-date: Thu, 29 Apr 2010 04:16:19 -0700

List-id: Xen developer discussion <xen-devel.lists.xensource.com>

Thread-index: AcrgS919AC3RHXCET4295IJeXmmgRwAO/3swAAIUDKAAASh2WgADOhngAFTDsG8BZeL8EA==

Thread-topic: [PATCH] CPUIDLE: shorten hpet spin_lock holding time

On Thursday, 2010-4-22 4:21 PM, Keir Fraser wrote: > On 20/04/2010 17:05, "Wei, Gang" <gang.wei@xxxxxxxxx> wrote: > >> Resend. >> >> CPUIDLE: shorten hpet spin_lock holding time >> >> Try to reduce spin_lock overhead for deep C state entry/exit. This >> will benefit systems with a lot of cpus which need the hpet >> broadcast to wakeup from deep C state. >> >> Signed-off-by: Wei Gang <gang.wei@xxxxxxxxx> > > I was going to ask: do you still get the decent power-saving win from > this new version of the patch? You acquire/release the lock a lot more > potentially in this version, since you do so inside the loop over > cpumask in handle_hpet_broadcast(). Yes, I tested it and could still get the decent power-saving win from it. And it should not have racing issue after the mwait-wakeup re-implementation patch. Jimmy _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel

©2013 Xen Project, A Linux Foundation Collaborative Project. All Rights Reserved.
Linux Foundation is a registered trademark of The Linux Foundation.
Xen Project is a trademark of The Linux Foundation.