From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753897AbYIAIbm (ORCPT ); Mon, 1 Sep 2008 04:31:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751968AbYIAIbd (ORCPT ); Mon, 1 Sep 2008 04:31:33 -0400 Received: from ug-out-1314.google.com ([66.249.92.173]:11216 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751912AbYIAIbc (ORCPT ); Mon, 1 Sep 2008 04:31:32 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding :sender; b=L3RfCell2+d8jZZVspzJcGZVh6Gj+am5R5e9jCas41g9uXf/79j3vkZ9G0z/ltm/uB rFSEp8WTdVMTj+syygk3KGnmOon54yz9Pyg4BozOQINO6MUpru6B6THHfJy6xS5kTEv2 qZPA3wVEBMkTpLkM7gidr7W9iiMaiholoXg0A= Message-ID: <48BBA85F.2010906@panasas.com> Date: Mon, 01 Sep 2008 11:31:27 +0300 From: Benny Halevy User-Agent: Thunderbird 3.0a1 (X11/2008050714) MIME-Version: 1.0 To: Andrew Morton CC: Joe Korty , "mingo@elte.hu" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] shrink printk timestamp field References: <20080827151759.GA10678@tsunami.ccur.com> <20080829163540.634e86d9.akpm@linux-foundation.org> <20080830143808.GA10821@tsunami.ccur.com> <20080830101618.b6c2e1ab.akpm@linux-foundation.org> In-Reply-To: <20080830101618.b6c2e1ab.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 On Aug. 30, 2008, 20:16 +0300, Andrew Morton wrote: > On Sat, 30 Aug 2008 10:38:08 -0400 Joe Korty wrote: > >> On Fri, Aug 29, 2008 at 07:35:40PM -0400, Andrew Morton wrote: >>> On Wed, 27 Aug 2008 11:17:59 -0400 Joe Korty wrote: >>> >>>> Shrink the printk timestamp field. >>>> >>>> Keep the printk timestamp from occupying more of the >>>> scarce, 80-column console line space than it really needs. >>>> >>> This is a significant loss in utility. >>> >>> [ 16.817285] md: Autodetecting RAID arrays. >>> [ 16.817288] md: Scanned 0 and added 0 devices. >>> [ 16.817290] md: autorun ... >>> [ 16.817292] md: ... autorun DONE. >>> >>> This not-terribly-fast machine can emit printks into the log buffer >>> within two microseconds. That's a pretty useful ad-hoc timing >>> factility. >>> >>> This patch will reduce the precision by a factor of five hundred. >> I was looking at it from the point of view of finding out where the >> boot process was too slow. For that millisecs is enough. I am not >> sure where knowing printk output to the microsec would be useful for >> solving anything. >> > > Of course it's useful. If you're working on performance or latency in > a disk, network or USB driver, microsecond resolution is about right. How about supporting a configurable format string either by .config and/or in runtime, e.g. given by a command line parameter? Benny > > -- > 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/