Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753441Ab2HUAXp (ORCPT ); Mon, 20 Aug 2012 20:23:45 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:61820 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751428Ab2HUAXn (ORCPT ); Mon, 20 Aug 2012 20:23:43 -0400 X-AuditID: 9c930179-b7cc4ae00000134d-61-5032d50d02ad From: Namhyung Kim To: Xin Tong Cc: Mike Galbraith , linux-kernel Subject: Re: changing timeslice in linux References: <1345442050.25011.38.camel@marge.simpson.net> Date: Tue, 21 Aug 2012 09:16:50 +0900 In-Reply-To: (Xin Tong's message of "Mon, 20 Aug 2012 07:51:52 -0700") Message-ID: <87mx1phzf1.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1496 Lines: 35 On Mon, 20 Aug 2012 07:51:52 -0700, Xin Tong wrote: > 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 ? You can find those files under /proc/sys/kernel/. Thanks, Namhyung -- 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/