Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965061AbWECAxs (ORCPT ); Tue, 2 May 2006 20:53:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965060AbWECAxs (ORCPT ); Tue, 2 May 2006 20:53:48 -0400 Received: from smtp102.mail.mud.yahoo.com ([209.191.85.212]:38822 "HELO smtp102.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S965061AbWECAxr (ORCPT ); Tue, 2 May 2006 20:53:47 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=N/MB58IHVXndKEBD+rOB/kWjqBBQR4LJ8VgGgiwAYlpIVnq7Mxl3+HeylDkSfg00aDZOTcLZ911i7dbnbQyC1tzw8tVV/Dyc7xIJy3B0h2OLoRp178vVP0lxCAohWiq/v3xQ+RYWlEyFh9nE7q6e70ypxn7KS7ohn0BTUj07fc8= ; Message-ID: <445791D3.9060306@yahoo.com.au> Date: Wed, 03 May 2006 03:07:31 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Andi Kleen CC: Christopher Friesen , Russell King , linux-kernel@vger.kernel.org Subject: Re: sched_clock() uses are broken References: <20060502132953.GA30146@flint.arm.linux.org.uk> <44578EB9.8050402@nortel.com> <200605021859.18948.ak@suse.de> In-Reply-To: <200605021859.18948.ak@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1127 Lines: 30 Andi Kleen wrote: > On Tuesday 02 May 2006 18:54, Christopher Friesen wrote: > >>Andi Kleen wrote: >> >> >>>Agreed it's a problem, but probably a small one. At worst you'll get >>>a small scheduling hickup every half year, which should be hardly >>>that big an issue. >> >>Presumably this would be bad for soft-realtime embedded things. Set-top >>boxes, etc. > > > SCHED_RR/FIFO are not affected. AFAIK it's only used by the interactivity > detector in the normal scheduler. Worst case that happens is that a > process is not detected to be interactive when it should once, which > gives it only a small penalty. On the next time slice everything will be ok again. Other problem is that some people didn't RTFM and have started trying to use it for precise accounting :( -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/