From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: Windows slow boot: contractor wanted Date: Sat, 25 Aug 2012 14:11:48 -0400 Message-ID: <50391564.30401@redhat.com> References: <20120817123642.GA16736@alpha.arachsys.com> <5030F273.5080706@redhat.com> <20120820135656.GA16676@alpha.arachsys.com> <50334E13.8020100@redhat.com> <20120821152107.GA16363@alpha.arachsys.com> <5034A18B.5040408@redhat.com> <20120822124032.GA12647@alpha.arachsys.com> <5034D437.8070106@redhat.com> <20120822144150.GA1400@alpha.arachsys.com> <5034F8F4.3080301@redhat.com> <20120825174550.GA8619@alpha.arachsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , qemu-devel@nongnu.org, kvm@vger.kernel.org To: Richard Davies Return-path: Received: from mx1.redhat.com ([209.132.183.28]:14676 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751376Ab2HYSLz (ORCPT ); Sat, 25 Aug 2012 14:11:55 -0400 In-Reply-To: <20120825174550.GA8619@alpha.arachsys.com> Sender: kvm-owner@vger.kernel.org List-ID: On 08/25/2012 01:45 PM, Richard Davies wrote: > Are you talking about these patches? > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=c67fe3752abe6ab47639e2f9b836900c3dc3da84 > http://marc.info/?l=linux-mm&m=134521289221259 > > If so, I believe those are in 3.6.0-rc3, so I tested with that. > > Unfortunately, I can still get the slow boots and perf top showing > _raw_spin_lock_irqsave. > > > Here are two perf top traces on 3.6.0-rc3. They do look a bit different from > 3.5.2, but _raw_spin_lock_irqsave is still at the top: > > PerfTop: 35272 irqs/sec kernel:98.1% exact: 0.0% [4000Hz cycles], (all, 16 CPUs) > ------------------------------------------------------------------------------------------------------------------ > > 61.85% [kernel] [k] _raw_spin_lock_irqsave > 7.18% [kernel] [k] sub_preempt_count > 5.03% [kernel] [k] isolate_freepages_block > 2.49% [kernel] [k] yield_to > 2.05% [kernel] [k] memcmp > 2.01% [kernel] [k] compact_zone > 1.76% [kernel] [k] add_preempt_count > 1.52% [kernel] [k] _raw_spin_lock > 1.31% [kernel] [k] kvm_vcpu_on_spin > 0.92% [kernel] [k] svm_vcpu_run However, the compaction code is not as prominent as before. Can you get a backtrace to that _raw_spin_lock_irqsave, to see from where it is running into lock contention? It would be good to know whether it is isolate_freepages_block, yield_to, kvm_vcpu_on_spin or something else... -- All rights reversed