Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755271Ab3CLJl7 (ORCPT ); Tue, 12 Mar 2013 05:41:59 -0400 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:41441 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755039Ab3CLJl5 (ORCPT ); Tue, 12 Mar 2013 05:41:57 -0400 Message-ID: <513EF856.7060200@linux.vnet.ibm.com> Date: Tue, 12 Mar 2013 17:41:42 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Ingo Molnar CC: Peter Zijlstra , LKML , Mike Galbraith , Namhyung Kim , Alex Shi , Paul Turner , Andrew Morton , "Nikunj A. Dadhania" , Ram Pai Subject: Re: [PATCH] sched: wakeup buddy References: <5136EB06.2050905@linux.vnet.ibm.com> <1362645372.2606.11.camel@laptop> <20130311082105.GB12742@gmail.com> <513DA076.80009@linux.vnet.ibm.com> <20130311094031.GA14221@gmail.com> <513EC47E.9040602@linux.vnet.ibm.com> <20130312084857.GA4859@gmail.com> In-Reply-To: <20130312084857.GA4859@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13031209-5564-0000-0000-000006FC85F4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1726 Lines: 48 On 03/12/2013 04:48 PM, Ingo Molnar wrote: [snip] >>> >>> Instrumentation/stats/profiling will also double check the correctness of >>> this data: if developers/users start relying on the work metric as a >>> substitute benchmark number, then app writers will have an additional >>> incentive to make them correct. >> >> I see, I could not figure out how to wisely using the info currently, >> but I have the feeling that it will make scheduler very different ;-) >> >> May be we could implement the API and get those info ready firstly >> (along with the new sched-pipe which provide work tick info), then think >> about the way to use them in scheduler, is there any patches on the way? > > Absolutely. > > Beyond the new prctl no new API is needed: a perf soft event could be > added, and/or a tracepoint. Then perf stat and perf record could be used > with it. 'perf bench' could be extended to generate the work tick in its > 'perf bench sched ...' workloads - and for 'perf bench mem numa' as well. Nice :) > > vsyscall-accelerating it could be a separate, more complex step: it needs > a per thread writable vsyscall data area to make the overhead to > applications near zero. Performance critical apps won't call an extra > syscall. If it's really bring benefit, I think they will consider about it, whatever, that's the developer/users decision, what we need to do is just make the stuff attractively. Regards, Michael Wang > > Thanks, > > Ingo > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/