From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753444AbZETEvB (ORCPT ); Wed, 20 May 2009 00:51:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750899AbZETEuw (ORCPT ); Wed, 20 May 2009 00:50:52 -0400 Received: from yx-out-2324.google.com ([74.125.44.28]:39621 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750784AbZETEuv convert rfc822-to-8bit (ORCPT ); Wed, 20 May 2009 00:50:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=cNM9gZ9sgDkN077yK1XatM5iLVNc6ibUvfp4AKzykYRiXS84d8/KCL7DxBCaays7Lv fnisZFYEcf9JbnTyZ3votBnoFAYmTpBGUq/02dBT5KfzYbtnbytHg0RK+z9Ww+k8epUc VJ7ICW6tTdkGqmgOuXVR31nP1P/37M1HlnsJs= MIME-Version: 1.0 In-Reply-To: <1242783552.31161.53.camel@centos51> References: <1242783552.31161.53.camel@centos51> Date: Wed, 20 May 2009 13:50:52 +0900 Message-ID: <49b7c2350905192150n4d6b710er571b8a1bd228198b@mail.gmail.com> Subject: Re: [PATCH 0/1] sched: fix typo in sched-rt-group.txt file From: GeunSik Lim To: Ingo Molnar Cc: Peter Zijlstra , Steven Rostedt , tglx , linux-kernel , linux-rt-users Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2009/5/20 GeunSik Lim : > > > Dear Ingo, > > > I made 2 patch files again about static prioriy levels according to ingo's advice > and explanation. (Reference: http://marc.info/?t=124211992800003&r=1&w=2 archives. ) > > Fix static priority related range and chart map(userspace/kernelspace) of ftrace. >   - about chart map of static priority in  ftrace.txt file >   - about static priority levels(range) in sched-rt-group.txt file > > > commit d6af702008117ca489a2f5476239d1688a517e98 > Author: GeunSik,Lim > Date:   Tue May 12 17:20:32 2009 +0900 > >    sched: fix typo in sched-rt-group.txt file > >    Fix typo about static priority's range. > >    * Kernel Space priority 0(high) to 99(low)   --> User Space RT priority 99(high) to 1(low) >    * Kernel Space priority 100(high) to 139(low)--> User Space nice -20(high) to 19(low) > Ingo, I want to change some descriptions according to below discussion. before) * Kernel Space priority 0(high) to 99(low) --> User Space RT priority 99(high) to 1(low) after) * Kernel Space priority 0(high) to 98(low) --> User Space RT priority 99(high) to 1(low) I want to your advice and opinion about this changes. If I mistook, Please correct me. thks. Steven Rostedt: Shouldn't that be: Kernel priority: 0(high) to 98(low) ==> user RT priority 99(high) to 1(low) GeunSik Lim : Thank you for your opinion. I think about corrected expression for quick chart to map between kernel space and user space in ftrace . Steven Rostedt: 100 items does not map to 99. Which begs the question, what can have internal kernel priority 99? GeunSik Lim : ok. Below example is about kernel (static) priority 99 that you said. please, refer to http://www.kernel.org/doc/man-pages/online/pages/man2/sched_setscheduler.2.html webpage. For processes scheduled under one of the normal scheduling policies (SCHED_OTHER, SCHED_IDLE, SCHED_BATCH), sched_priority is not used in scheduling decisions (it must be specified as 0). int main (int argc, char **argv) { int pidnumber, ret; struct sched_param p; p.sched_priority = 0; <------ Kernel (static) priority. if (argc != 2) { printf("usage: setbatch \n"); exit(-1); } pidnumber = atol(argv[1]); /* 3 = Number of SCHED_BATCH Constant */ ret = sched_setscheduler(pidnumber, 3, &p); if (ret) { printf("could not set pid %d to SCHED_BATCH: err %d.\n", pid, ret); return -1; } printf("pid %d is SCHED_BATCH from now on.\n", pid); return 0; } > >    Processes scheduled with SCHED_OTHER or SCHED_BATCH must be assigned >    the static priority 0. Processes scheduled under SCHED_FIFO or SCHED_RR >    can have a static priority in the range 1 to 99. >    (reference: $> man 2 sched_setscheduler) > >    Signed-off-by: GeunSik Lim > > diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt > index 5ba4d3f..1537146 100644 > --- a/Documentation/scheduler/sched-rt-group.txt > +++ b/Documentation/scheduler/sched-rt-group.txt > @@ -169,7 +169,7 @@ get their allocated time. > >  Implementing SCHED_EDF might take a while to complete. Priority Inheritance is >  the biggest challenge as the current linux PI infrastructure is geared towards > -the limited static priority levels 0-139. With deadline scheduling you need to > +the limited static priority levels 0-99. With deadline scheduling you need to >  do deadline inheritance (since priority is inversely proportional to the >  deadline delta (deadline - now). > > > > > ----------------------------------------------- > To unsubscribe from this list: send the line "unsubscribe linux-***" > 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/ > > GeunSik Lim (ELS - OS Group - S/W Lab - SAIT - SAMSUNG) > e-Mail  :1) geunsik.lim@samsung.com >         2) leemgs@gmail.com , leemgs1@gmail.com > HomePage: http://intomail.dnip.net/invain/me/ > ----------------------------------------------- > -- Regards, GeunSik Lim -- 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/