From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755437Ab2DFJOv (ORCPT ); Fri, 6 Apr 2012 05:14:51 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:45808 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752822Ab2DFJOt (ORCPT ); Fri, 6 Apr 2012 05:14:49 -0400 Message-ID: <4F7EB406.5020703@linaro.org> Date: Fri, 06 Apr 2012 13:14:46 +0400 From: Dmitry Antipov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120327 Thunderbird/11.0.1 MIME-Version: 1.0 To: Andrew Morton CC: Thomas Gleixner , linux-kernel@vger.kernel.org, linaro-dev@lists.linaro.org, patches@linaro.org, linux-man@vger.kernel.org Subject: Re: [RFC PATCH] hrtimers: system-wide and per-task hrtimer slacks References: <1329724172-27690-1-git-send-email-dmitry.antipov@linaro.org> <20120404171013.ac08575d.akpm@linux-foundation.org> In-Reply-To: <20120404171013.ac08575d.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/05/2012 04:10 AM, Andrew Morton wrote: > Well.. there are some back-incompatibilities here. > prctl(PR_SET_TIMERSLACK, -1) used to restore current's slack setting to > whatever-we-inherited-at-fork, but that has been removed. What are the > implications of this, and did we need to do it? It seems you're looking at the previous version of this patch (http://lkml.org/lkml/2012/2/20/55). Latest proposal is http://lwn.net/Articles/484162/, which defines PR_SET_TIMERSLACK action as: ... case PR_SET_TIMERSLACK: if (arg2 <= 0) current->timer_slack_ns = default_timer_slack_ns; else if (arg2 <= HRTIMER_MAX_SLACK) current->timer_slack_ns = arg2; else error = -EINVAL; break; ... > If we do make changes in this area then the prctl manpage should be > updated, please. And if > http://www.spinics.net/lists/linux-man/msg01149.html represents the > current state of that manpage then it should be updated anyway - that > entry doesn't say anything about the (arg2<= 0) case. I sent a patch for man pages too, it should be one of the recent posts at http://www.spinics.net/lists/linux-man/index.html. Dmitry