From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v5 0/9] KVM: fast page fault Date: Wed, 23 May 2012 14:37:45 +0300 Message-ID: <4FBCCC09.3020605@redhat.com> References: <4FBCA4FB.8050501@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM To: Xiao Guangrong Return-path: In-Reply-To: <4FBCA4FB.8050501@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 05/23/2012 11:51 AM, Xiao Guangrong wrote: > Changlog: > This are some changes from Marcelo's review: > - drop SPTE_WRITE_PROTECT bit, now, only one bit is needed to do > lockless update. > > - always atomicly update spte if it can be updated out of mmu-lock. > > - flod the judgement of tlb flush into mmu_spte_update(), make the > code easilyer audited. > > Performance result: > - autoest migration test (smp2.Fedora.16.64.migrate.with_autotest.dbench.unix): > before after > smp2.Fedora.16.64.migrate.unix 93 91 +2.1% > smp2.Fedora.16.64.migrate.with_autotest.dbench.unix 218 188 +13.7% > > - the benchmark attached is used to measure the resuming time > after dirty-log > before after > Run 10 times, Avg time: 512466818 ns. 269231261 ns +47.5% Still scary (esp. indirect sptes), but looks pretty good. -- error compiling committee.c: too many arguments to function