Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756215Ab0G1VFl (ORCPT ); Wed, 28 Jul 2010 17:05:41 -0400 Received: from wolverine01.qualcomm.com ([199.106.114.254]:46291 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754991Ab0G1VFj (ORCPT ); Wed, 28 Jul 2010 17:05:39 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6057"; a="49114291" Message-ID: <4C509BA3.7090403@codeaurora.org> Date: Wed, 28 Jul 2010 14:05:39 -0700 From: Patrick Pannuto User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12pre) Gecko/20100715 Shredder/3.0.7pre MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel@vger.kernel.org, apw@canonical.com, corbet@lwn.net, Thomas Gleixner , Ingo Molnar , Arjan van de Ven , Akinobu Mita Subject: Re: [PATCH 1/4] timer: Added usleep[_range] timer References: <1280345587-19725-1-git-send-email-ppannuto@codeaurora.org> <1280345587-19725-2-git-send-email-ppannuto@codeaurora.org> <20100728132314.29cd68c5.akpm@linux-foundation.org> <4C509772.1070407@codeaurora.org> <20100728135857.2a0ab8bd.akpm@linux-foundation.org> In-Reply-To: <20100728135857.2a0ab8bd.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1414 Lines: 33 On 07/28/2010 01:58 PM, Andrew Morton wrote: > On Wed, 28 Jul 2010 13:47:46 -0700 > Patrick Pannuto wrote: > >>> This is different from the patch I merged and I'm not seeing any >>> explanation for the change. >>> >>> The implementation of usleep() looks odd. The longer we sleep, the >>> greater the possible inaccuracy. A code comment which explains the >>> thinking and which warns people about the implications is needed. > > I wanna code comment! > I understand -- will do (if this even survives, which is unlikely) > My main concern is that someone will type usleep(50) and won't realise > that it goes and sleeps for 100 usecs and their code gets slow as a > result. This sort of thing takes *years* to discover and fix. If we'd > forced them to type usleep_range() instead, it would never have happened. In that case, it would push me in the direction of only providing usleep_range, and thus forcing people to think about it that way; leave slack decisions to people who know what tolerances are acceptable. -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum -- 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/