From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH/RFC 4/4] Add support for dynamic ticks. Date: Sun, 19 Aug 2007 11:08:42 +0300 Message-ID: <46C7FA8A.2090900@qumranet.com> References: <11872968773449-git-send-email-kronos.it@gmail.com> <11872968771257-git-send-email-kronos.it@gmail.com> <11872968773155-git-send-email-kronos.it@gmail.com> <11872968773524-git-send-email-kronos.it@gmail.com> <1187296877557-git-send-email-kronos.it@gmail.com> <42755.207.81.93.54.1187334969.squirrel@mail.voxel.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Dan Kenigsberg , qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org To: Matthew Kent Return-path: In-Reply-To: <42755.207.81.93.54.1187334969.squirrel-N19E6/cp6YFSV923RJcDwA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Matthew Kent wrote: >> If DYNAMIC_TICKS is defined qemu does not attepmt to generate SIGALRM at a >> constant rate. Rather, the system timer is set to generate SIGALRM only >> when it is needed. DYNAMIC_TICKS reduces the number of SIGALRMs sent to >> idle dynamic-ticked guests. >> Original patch from Dan Kenigsberg >> >> Signed-off-by: Luca Tettamanti >> > > Wow, this patch sure made a difference for some timings I've been doing > with kvm-35 and hackbench. All tests using 2.6.23-rc3+hrtimers patch for > x86_64/i386 tickless and a quad core intel: > > [mkent@localhost ~]$ time ./hackbench 50 > x86_64 host : real 0m10.845s > x86_64 host, bound to 1 cpu : real 0m21.884s > i386 guest+unix clock : real 0m49.206s > i386 guest+hpet clock : real 0m48.292s > i386 guest+dynticks clock : real 0m28.835s > > Results are repeatable and verfied with a stopwatch because I didn't > believe them at first :) > > Great stuff. > I'm not sure what these results mean... -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/