From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH v7 04/11] KVM: MMU: zap pages in batch Date: Mon, 27 May 2013 10:20:12 +0800 Message-ID: <51A2C2DC.6080403@linux.vnet.ibm.com> References: <1369252560-11611-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com> <1369252560-11611-5-git-send-email-xiaoguangrong@linux.vnet.ibm.com> <20130524203432.GB4525@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: gleb@redhat.com, avi.kivity@gmail.com, pbonzini@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org To: Marcelo Tosatti Return-path: In-Reply-To: <20130524203432.GB4525@amt.cnet> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 05/25/2013 04:34 AM, Marcelo Tosatti wrote: > On Thu, May 23, 2013 at 03:55:53AM +0800, Xiao Guangrong wrote: >> Zap at lease 10 pages before releasing mmu-lock to reduce the overload >> caused by requiring lock >> >> After the patch, kvm_zap_obsolete_pages can forward progress anyway, >> so update the comments >> >> [ It improves kernel building 0.6% ~ 1% ] > > Can you please describe the overload in more detail? Under what scenario > is kernel building improved? Yes. The scenario is we do kernel building, meanwhile, repeatedly read PCI rom every one second. [ echo 1 > /sys/bus/pci/devices/0000\:00\:03.0/rom cat /sys/bus/pci/devices/0000\:00\:03.0/rom > /dev/null ]