From: Balbir Singh <balbir@linux.vnet.ibm.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm <kvm@vger.kernel.org>
Subject: Re: [PATCH RFC] KVM: busy-spin detector
Date: Fri, 11 Jun 2010 19:36:34 +0530 [thread overview]
Message-ID: <20100611140634.GI5191@balbir.in.ibm.com> (raw)
In-Reply-To: <20100611022551.GA16223@amt.cnet>
* Marcelo Tosatti <mtosatti@redhat.com> [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
next prev parent reply other threads:[~2010-06-11 14:07 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-11 2:25 [PATCH RFC] KVM: busy-spin detector Marcelo Tosatti
2010-06-11 14:06 ` Balbir Singh [this message]
2010-06-11 15:03 ` Huang, Zhiteng
2010-06-11 17:38 ` Balbir Singh
2010-06-11 17:46 ` Marcelo Tosatti
2010-06-11 19:18 ` Balbir Singh
2010-06-16 8:22 ` Avi Kivity
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