From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267361AbUHPCpE (ORCPT ); Sun, 15 Aug 2004 22:45:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267363AbUHPCpE (ORCPT ); Sun, 15 Aug 2004 22:45:04 -0400 Received: from mustang.oldcity.dca.net ([216.158.38.3]:14503 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S267361AbUHPCov (ORCPT ); Sun, 15 Aug 2004 22:44:51 -0400 Subject: Re: [patch] voluntary-preempt-2.6.8.1-P0 From: Lee Revell To: Ingo Molnar Cc: Florian Schmidt , linux-kernel , Felipe Alfaro Solana In-Reply-To: <20040816024314.GA8960@elte.hu> References: <20040809104649.GA13299@elte.hu> <20040810132654.GA28915@elte.hu> <20040812235116.GA27838@elte.hu> <1092382825.3450.19.camel@mindpipe> <20040813104817.GI8135@elte.hu> <1092432929.3450.78.camel@mindpipe> <20040814072009.GA6535@elte.hu> <20040815115649.GA26259@elte.hu> <20040816022554.16c3c84a@mango.fruits.de> <1092622121.867.109.camel@krustophenia.net> <20040816024314.GA8960@elte.hu> Content-Type: text/plain Message-Id: <1092624336.867.121.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sun, 15 Aug 2004 22:45:37 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2004-08-15 at 22:43, Ingo Molnar wrote: > * Lee Revell wrote: > > > http://krustophenia.net/testresults.php?dataset=2.6.8.1-P0 > > nice. (What is the difference between the left-hand and the right-hand > graphs - why is the right-hand side one 'wider'?) > The right hand graph is logarithmically scaled on the y axis (set logscale y in gnuplot). Some of the latencies are rare enough to not show up at all on the linear scale, like the peak in the 400s. > > The peaks on this graph should correspond directly to the length of > > the non-preemptible critical section reported by Ingo's latency > > tracer. I think the large peak around 580-600usecs is caused by the > > extract_entropy issue (which can be hit by regular processes and > > ksoftirqd), and the large peak around 80-100 by the XFree86 unmap_vmas > > issue, as the times match and these are by far the most common > > reported in latency_trace. > > just to check this theory, could you make __check_and_rekey() an empty > function? This should still produce a working random driver, albeit at > much reduced entropy. If these latencies have a relationship to the > mlockall() issue then this change should have an effect. > Sure, will try this next. Lee