Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756916Ab2HTOvz (ORCPT ); Mon, 20 Aug 2012 10:51:55 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:62370 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756827Ab2HTOvw (ORCPT ); Mon, 20 Aug 2012 10:51:52 -0400 MIME-Version: 1.0 In-Reply-To: <1345442050.25011.38.camel@marge.simpson.net> References: <1345442050.25011.38.camel@marge.simpson.net> Date: Mon, 20 Aug 2012 07:51:52 -0700 Message-ID: Subject: Re: changing timeslice in linux From: Xin Tong To: Mike Galbraith Cc: linux-kernel Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1351 Lines: 31 On Sun, Aug 19, 2012 at 10:54 PM, Mike Galbraith wrote: > On Sun, 2012-08-19 at 11:58 -0700, Xin Tong wrote: >> I have 2 questions about linux 2.6 x86_64 scheduler. >> >> 1. is the default scheduling algorithm SCHED_NORMAL in linux ? > > Yes. Is there any document describing what the sched_normal is ? it is more difficult than SCHED_RR to infer its meaning just based on its name ? > >> 2. how do i change the time slice in linux source code ? > > You shouldn't need to. You can tune "slice" by adjusting > sched_latency_ns and sched_min_granularity_ns, but note that "slice" is > not a fixed quantum. Also note that CFS preemption decisions are based > upon instantaneous state. A task may have received a full (variable) > "slice" of CPU time, but preemption will be triggered only if a more > deserving task is available, so a "slice" is not the "max uninterrupted > CPU time" that you may expect it to be.. but it is somewhat similar. > > -Mike > This can be done without recompiling and reinstalling the kernel ? maybe one simply needs to write to a device file under /dev ? Xin -- 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/