From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0/2] Faster MMU lookups for Book3s v3 Date: Thu, 01 Jul 2010 10:29:04 +0300 Message-ID: <4C2C43C0.4000400@redhat.com> References: <1277903926-12786-1-git-send-email-agraf@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm-ppc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, KVM list , linuxppc-dev To: Alexander Graf Return-path: In-Reply-To: <1277903926-12786-1-git-send-email-agraf-l3A5Bk7waGM@public.gmane.org> Sender: kvm-ppc-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: kvm.vger.kernel.org On 06/30/2010 04:18 PM, Alexander Graf wrote: > Book3s suffered from my really bad shadow MMU implementation so far. So > I finally got around to implement a combined hash and list mechanism that > allows for much faster lookup of mapped pages. > > To show that it really is faster, I tried to run simple process spawning > code inside the guest with and without these patches: > > [without] > > debian-powerpc:~# time for i in {1..1000}; do /bin/echo hello> /dev/null; done > > real 0m20.235s > user 0m10.418s > sys 0m9.766s > > [with] > > debian-powerpc:~# time for i in {1..1000}; do /bin/echo hello> /dev/null; done > > real 0m14.659s > user 0m8.967s > sys 0m5.688s > > So as you can see, performance improved significantly. > > v2 -> v3: > > - use hlist > - use global slab cache > > Looks good. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.