From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] add PLE stats to kvmstat Date: Sun, 08 Jul 2012 12:50:39 +0300 Message-ID: <4FF957EF.3060003@redhat.com> References: <1341525037.12425.46.camel@oc2024037011.ibm.com> <4FF69703.9080402@linux.vnet.ibm.com> <1341580976.12425.50.camel@oc2024037011.ibm.com> <4FF72328.4060907@gmail.com> <1341598353.12425.54.camel@oc2024037011.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Xiao Guangrong , Xiao Guangrong , kvm@vger.kernel.org To: habanero@linux.vnet.ibm.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36000 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751272Ab2GHKLu (ORCPT ); Sun, 8 Jul 2012 06:11:50 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q68ABoev009311 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 8 Jul 2012 06:11:50 -0400 In-Reply-To: <1341598353.12425.54.camel@oc2024037011.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On 07/06/2012 09:12 PM, Andrew Theurer wrote: > On Sat, 2012-07-07 at 01:40 +0800, Xiao Guangrong wrote: >> On 07/06/2012 09:22 PM, Andrew Theurer wrote: >> > On Fri, 2012-07-06 at 15:42 +0800, Xiao Guangrong wrote: >> >> On 07/06/2012 05:50 AM, Andrew Theurer wrote: >> >>> I, and I expect others, have a keen interest in knowing how often we >> >>> exit for PLE, and also how often that includes a yielding to another >> >>> vcpu. The following adds two more counters to kvmstat to track the >> >>> exits and the vcpu yields. This in no way changes PLE behavior, just >> >>> helps us track what's going on. >> >>> >> >> >> >> Tracepoint is a better choice than the counters you used. :) >> > >> > Xiao, is kvmstat considered to be deprecated? Or are debug stats like >> > this just generally favored to be processed via something like perf >> > instead of debugfs? >> >> Andrew, please refer to Documentation/feature-removal-schedule.txt, >> it says: >> >> What: KVM debugfs statistics >> When: 2013 >> Why: KVM tracepoints provide mostly equivalent information in a much more >> flexible fashion. >> >> You can use tracepoints instead of your debugfs-counters in this patch. > > Great, thanks. I will work on a tracepoint based approach. >> >> > Should we be removing kvmstat? >> > >> >> Some months ago, i implemented 'perf kvm-events' which can analyse kvm >> events more smartly, the patchset can be found at: >> https://lkml.org/lkml/2012/3/6/86 > > I will take a look. >> >> Avi said it may instead of kvmstat, but i am too busy to update this >> patchset. :) >> Note, kvm_stat is able to use both the old debugfs based statistics and the tracepoint based events. The latter requires root privileges. (bonus: pressing 'x' expands the kvm_exit statistic to include information about the various hardware exit reasons). -- error compiling committee.c: too many arguments to function