PLE-like design may be more generic than para-virtish when it comes to Windows guest. Is this busy-spin actually a Lock Holder Preemption problem? Regards, HUANG, Zhiteng -----Original Message----- From: kvm-owner@xxxxxxxxxxxxxxx [mailto:kvm-owner@xxxxxxxxxxxxxxx] On Behalf Of Balbir Singh Sent: Friday, June 11, 2010 10:07 PM To: Marcelo Tosatti Cc: kvm Subject: Re: [PATCH RFC] KVM: busy-spin detector * Marcelo Tosatti <mtosatti@xxxxxxxxxx> [2010-06-10 23:25:51]: > > The following patch implements a simple busy-spin detector. It > considers a vcpu as busy-spinning if there are two consecutive exits > due to external interrupt on the same RIP, and sleeps for 100us in that case. > > It is very likely that if the vcpu is making progress it will either > exit for other reasons or change RIP. > > The percentage numbers below represent improvement in kernel build > time in comparison with mainline (RHEL 5.4 guest). > Interesting approach, is there a reason to tie it in with pause loop exits? Can't we do something more generic or even para-virtish. -- Three Cheers, Balbir -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
