From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emmanuel Ackaouy Subject: Re: [Q] about Credit Scheduler Dom0 Scheduling policy. Date: Thu, 26 Oct 2006 09:42:11 +0100 Message-ID: <20061026084210.GA3497@cockermouth.uk.xensource.com> References: <20061018131115.GA5327@cockermouth.uk.xensource.com> <20061018132410.GA5372@cockermouth.uk.xensource.com> <200610230414.k9N4EKGJ011580@fjmscan501.ms.jp.fujitsu.com> <20061023143210.GA26848@cockermouth.uk.xensource.com> <200610240647.k9O6lYQR004608@fjmscan503.ms.jp.fujitsu.com> <20061025102948.GA32281@cockermouth.uk.xensource.com> <200610251303.k9PD3CpQ017617@fjmscan501.ms.jp.fujitsu.com> <20061025140337.GA819@cockermouth.uk.xensource.com> <200610260615.k9Q6FiKi015422@fjmscan502.ms.jp.fujitsu.com> <200610260835.k9Q8ZvZZ025347@fjmscan502.ms.jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200610260835.k9Q8ZvZZ025347@fjmscan502.ms.jp.fujitsu.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Atsushi SAKAI Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Thanks. That indicates the dom0 and I/O generating domU are preempting the spinners but not each other and are therefore running optimally. That is great news. On Thu, Oct 26, 2006 at 05:35:20PM +0900, Atsushi SAKAI wrote: > Hi, Emmanuel > > Sorry for mis-reading it. > > The measured value to omit 2 SPIN DomU is same as w/ 2SPIN DomU. > > Result > > 44 > 133 > 533 > (Kbps) > > And xentop says > the CPU usage for Dom0 DomU3 is same as w/ 2 SPIN DomU > (Both Dom0 and DomU3 usages are 1.0 to 1.2 % ) > > Thanks, > Atsushi SAKAI > > >The bench mark is same as previous one. > > > >Only Dom0 and DomU3 are no spinning vcpus. > >Other DomU1 and DomU2 are spinning vcpus. > > > >#pcpu(s)=1 > >#vcpu(s)=2(no spinning) > >#vcpu(s)=2(spinning) > >#vcpu(s)=4(total spinning and no spinning) > > > >> > >>Out of curiosity, what are the numbers like when running this > >>benchmark with no spinning VCPUs competing? > >> > >>> With this patches, the CREDIT scheduler changed for I/O aware. > >>> (At vcpu_wake, the priority changes from UNDER to BOOST, > >>> At vcpu_acct, the priority changes from BOOST to UNDER.) > >>> > >>> It seems reasonable fixes! > >>> But I am afraid many I/O intensive GuestOSes are running. > >>> (I hope this prospect is needless fear.) > >> > >>I've been careful to prevent BOOSTed VCPUs from taking over the > >>system or otherwise impacting fairness: > >> > >>- Only VCPUs with positive credits can be boosted. > >>- While boosted, a VCPU is charged for any substential CPU > >> resources consumed. > >>- VCPUs can run uninterrupted with a boosted priority for no > >> more than 10ms (1/3-rd of a full time slice). > >> > >>Only VCPUs which consume a negligeable amount of CPU resources > >>should get real benefit from boosting. When multiple VCPUs are > >>boosted, they will round robin or be queued FIFO. The idea is > >>for a boosted VCPU to preempt spinners but not other boosted > >>I/O intensive guests. A VCPU cannot use the boosting mechanism > >>to consume more CPU than its allocated fair share. > > > >I agree. > > > >Thanks > >Atsushi SAKAI > > > > > > > > > >_______________________________________________ > >Xen-devel mailing list > >Xen-devel@lists.xensource.com > >http://lists.xensource.com/xen-devel > > > > > > >