From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1IkTYV-00088T-CK for user-mode-linux-devel@lists.sourceforge.net; Tue, 23 Oct 2007 16:53:03 -0700 Received: from rv-out-0910.google.com ([209.85.198.189]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1IkTYT-0002VT-W3 for user-mode-linux-devel@lists.sourceforge.net; Tue, 23 Oct 2007 16:53:03 -0700 Received: by rv-out-0910.google.com with SMTP id g11so82975rvb for ; Tue, 23 Oct 2007 16:53:01 -0700 (PDT) Message-ID: <1f154f440710231653s69d02dbepc552c5fe8d7f2b3f@mail.gmail.com> Date: Tue, 23 Oct 2007 19:53:01 -0400 From: Hrishikesh In-Reply-To: <20071023213545.GA11026@c2.user-mode-linux.org> MIME-Version: 1.0 References: <1f154f440710161936h4800b0c5nb3140ff504212625@mail.gmail.com> <20071017155504.GD9497@c2.user-mode-linux.org> <1f154f440710170916j4fdb857fw40c9b2fd2b66f63f@mail.gmail.com> <20071017171920.GA10388@c2.user-mode-linux.org> <1f154f440710171243x40898f8bq386c91c59789fb42@mail.gmail.com> <20071017204527.GB12812@c2.user-mode-linux.org> <1f154f440710171629meb5a3ces92b8fdeacc371857@mail.gmail.com> <20071018200432.GA9204@c2.user-mode-linux.org> <1f154f440710231221r76d63ec2h640e95c7afa05a6a@mail.gmail.com> <20071023213545.GA11026@c2.user-mode-linux.org> Subject: Re: [uml-devel] Dramatic drop in C3 state residency with NO_HZ patches List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============0342449029==" Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: Jeff Dike Cc: user-mode-linux-devel@lists.sourceforge.net --===============0342449029== Content-Type: multipart/alternative; boundary="----=_Part_5197_30321795.1193183581596" ------=_Part_5197_30321795.1193183581596 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline On 10/23/07, Jeff Dike wrote: > > On Tue, Oct 23, 2007 at 04:21:03PM -0300, Hrishikesh wrote: > >> Yes, that double negative was a slipup. I did get some numbers out and > they > >> look pretty good. I ran upto 5 instances of UML simultaneously and in > the > >> tickful case, each instance adds roughly about 100 wakeups per second. > > > HZ == 100, so that makes sense. >> So > >> after 5 instances, C3 residency comes down to about 95% when all the > >> instances are simply idling. With NO_HZ applied, the change is minimal > with > >> C3 residency still approximately 98%. UML is not even among the top > three of > >> the bad-list of wakers-up :-) > > > Cool. I'm suprised that 500 wakeups/sec only brings you down < 5%. Hmm, powertop shows 500 wakeups on part of UML, but the actual number of wakeups for the processor is much lesser.. Guess there is some batching that is happening. > So, things are good, except I need to figure out the !NO_HZ busy loop. > > > > Jeff > > > > -- > > Work email - jdike at linux dot intel dot com Hrishi ------=_Part_5197_30321795.1193183581596 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline

On 10/23/07, Jeff Dike <jdike@addtoit.com> wrote:
On Tue, Oct 23, 2007 at 04:21:03PM -0300, Hrishikesh wrote:
>> Yes, that double negative was a slipup. I did get some numbers out and they
>> look pretty good. I ran upto 5 instances of UML simultaneously and in the
>> tickful case, each instance adds roughly about 100 wakeups per second.

> HZ == 100, so that makes sense. 

>> So
>> after 5 instances, C3 residency comes down to about 95% when all the
>> instances are simply idling. With NO_HZ applied, the change is minimal with
>> C3 residency still approximately 98%. UML is not even among the top three of
>> the bad-list of wakers-up :-)

> Cool.  I'm suprised that 500 wakeups/sec only brings you down < 5%.

Hmm,  powertop shows  500 wakeups  on  part of UML, but the actual number of wakeups for the processor is much  lesser..  Guess there is  some  batching that  is happening.

> So, things are good, except I need to figure out the !NO_HZ busy loop.
>
>                                Jeff
>
> --
> Work email - jdike at linux dot intel dot com

Hrishi


------=_Part_5197_30321795.1193183581596-- --===============0342449029== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- 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/ --===============0342449029== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel --===============0342449029==--