From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266139AbUH1B74 (ORCPT ); Fri, 27 Aug 2004 21:59:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266189AbUH1B7z (ORCPT ); Fri, 27 Aug 2004 21:59:55 -0400 Received: from web13902.mail.yahoo.com ([216.136.175.28]:5178 "HELO web13902.mail.yahoo.com") by vger.kernel.org with SMTP id S266139AbUH1B7j (ORCPT ); Fri, 27 Aug 2004 21:59:39 -0400 Message-ID: <20040828015937.50607.qmail@web13902.mail.yahoo.com> Date: Fri, 27 Aug 2004 18:59:37 -0700 (PDT) From: Reply-To: spaminos-ker@yahoo.com Subject: Re: Scheduler fairness problem on 2.6 series (Attn: Nick Piggin and others) To: Peter Williams Cc: linux-kernel@vger.kernel.org In-Reply-To: <412DA1C3.6020505@bigpond.net.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --- Peter Williams wrote: > A (gzipped) combined ZAPHOD and P9 voluntary preempt patch for 2.6.8.1 > is available at: > > > > This patch has had minimal testing so use with care and please let me > know if there are any problems. > I tried this patch, and I get a pretty high latency in "sub_preempt_count" 00000001 0.730ms (+0.730ms): sub_preempt_count (_mmx_memcpy) I am not sure if that makes sense and what it means. Nicolas Here are the full messages: Aug 27 18:42:11 localhost kernel: (events/0/4): new 730 us maximum-latency critical section. Aug 27 18:42:11 localhost kernel: => started at: Aug 27 18:42:11 localhost kernel: => ended at: <_mmx_memcpy+0x131/0x180> Aug 27 18:42:11 localhost kernel: [] check_preempt_timing+0x1aa/0x240 Aug 27 18:42:11 localhost kernel: [] _mmx_memcpy+0x131/0x180 Aug 27 18:42:11 localhost kernel: [] _mmx_memcpy+0x131/0x180 Aug 27 18:42:11 localhost kernel: [] sub_preempt_count+0x54/0x60 Aug 27 18:42:11 localhost kernel: [] sub_preempt_count+0x54/0x60 Aug 27 18:42:11 localhost kernel: [] _mmx_memcpy+0x131/0x180 Aug 27 18:42:11 localhost kernel: [] vgacon_save_screen+0x7e/0x80 Aug 27 18:42:11 localhost kernel: [] do_blank_screen+0x182/0x2b0 Aug 27 18:42:11 localhost kernel: [] acquire_console_sem+0x44/0x70 Aug 27 18:42:11 localhost kernel: [] console_callback+0x72/0xf0 Aug 27 18:42:11 localhost kernel: [] worker_thread+0x1eb/0x2d0 Aug 27 18:42:11 localhost kernel: [] console_callback+0x0/0xf0 Aug 27 18:42:11 localhost kernel: [] default_wake_function+0x0/0x20 Aug 27 18:42:11 localhost kernel: [] default_wake_function+0x0/0x20 Aug 27 18:42:11 localhost kernel: [] kthread+0xbc/0xd0 Aug 27 18:42:11 localhost kernel: [] worker_thread+0x0/0x2d0 Aug 27 18:42:11 localhost kernel: [] kthread+0x0/0xd0 Aug 27 18:42:11 localhost kernel: [] kernel_thread_helper+0x5/0xc preemption latency trace v1.0.2 ------------------------------- latency: 730 us, entries: 4 (4) ----------------- | task: events/0/4, uid:0 nice:-10 policy:0 rt_prio:0 ----------------- => started at: kernel_fpu_begin+0x21/0x60 => ended at: _mmx_memcpy+0x131/0x180 =======> 00000001 0.000ms (+0.000ms): kernel_fpu_begin (_mmx_memcpy) 00000001 0.730ms (+0.730ms): sub_preempt_count (_mmx_memcpy) 00000001 0.730ms (+0.000ms): _mmx_memcpy (check_preempt_timing) 00000001 0.730ms (+0.000ms): kernel_fpu_begin (_mmx_memcpy)