From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266466AbUIABnw (ORCPT ); Tue, 31 Aug 2004 21:43:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266479AbUIABnw (ORCPT ); Tue, 31 Aug 2004 21:43:52 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:61061 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S266466AbUIABnq (ORCPT ); Tue, 31 Aug 2004 21:43:46 -0400 Subject: Re: [patch] voluntary-preempt-2.6.9-rc1-bk4-Q5 From: Lee Revell To: Ingo Molnar Cc: Daniel Schmitt , "K.R. Foley" , Felipe Alfaro Solana , linux-kernel , Mark_H_Johnson@raytheon.com In-Reply-To: <20040830090608.GA25443@elte.hu> References: <1093715573.8611.38.camel@krustophenia.net> <20040828194449.GA25732@elte.hu> <200408282210.03568.pnambic@unu.nu> <20040828203116.GA29686@elte.hu> <1093727453.8611.71.camel@krustophenia.net> <20040828211334.GA32009@elte.hu> <1093727817.860.1.camel@krustophenia.net> <1093737080.1385.2.camel@krustophenia.net> <1093746912.1312.4.camel@krustophenia.net> <20040829054339.GA16673@elte.hu> <20040830090608.GA25443@elte.hu> Content-Type: text/plain Message-Id: <1094003017.3404.44.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Tue, 31 Aug 2004 21:43:38 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2004-08-30 at 05:06, Ingo Molnar wrote: > i've uploaded -Q5 to: > > http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.9-rc1-bk4-Q5 This is with netdev_max_backlog = 1: preemption latency trace v1.0.2 ------------------------------- latency: 386 us, entries: 328 (328) ----------------- | task: ksoftirqd/0/2, uid:0 nice:-10 policy:0 rt_prio:0 ----------------- => started at: tcp_delack_timer+0x1c/0x1d0 => ended at: tcp_delack_timer+0x127/0x1d0 =======> 00000001 0.000ms (+0.000ms): tcp_delack_timer (run_timer_softirq) 00000001 0.000ms (+0.000ms): __sk_stream_mem_reclaim (tcp_delack_timer) 00000001 0.004ms (+0.003ms): tcp_v4_do_rcv (tcp_delack_timer) 00000001 0.005ms (+0.001ms): tcp_rcv_established (tcp_v4_do_rcv) 00000001 0.007ms (+0.001ms): __tcp_checksum_complete_user (tcp_rcv_established) 00000001 0.008ms (+0.000ms): skb_checksum (__tcp_checksum_complete_user) 00000001 0.018ms (+0.010ms): tcp_ack (tcp_rcv_established) 00000001 0.019ms (+0.001ms): tcp_ack_update_window (tcp_ack) 00000001 0.021ms (+0.001ms): tcp_urg (tcp_rcv_established) 00000001 0.021ms (+0.000ms): tcp_data_queue (tcp_rcv_established) 00000001 0.023ms (+0.001ms): sk_stream_mem_schedule (tcp_data_queue) ... 00000103 0.377ms (+0.000ms): skb_release_data (kfree_skbmem) 00000103 0.378ms (+0.000ms): kfree (kfree_skbmem) 00000103 0.379ms (+0.000ms): kmem_cache_free (kfree_skbmem) 00000103 0.383ms (+0.004ms): qdisc_restart (dev_queue_xmit) 00000103 0.384ms (+0.000ms): pfifo_fast_dequeue (qdisc_restart) 00000102 0.384ms (+0.000ms): local_bh_enable (dev_queue_xmit) 00000001 0.386ms (+0.001ms): sub_preempt_count (tcp_delack_timer) 00000001 0.387ms (+0.000ms): _mmx_memcpy (check_preempt_timing) 00000001 0.387ms (+0.000ms): kernel_fpu_begin (_mmx_memcpy) Also, I do not get the packet loss/timeout problems that another poster reported when setting this to 1. The network works normally, it just does not affect the latency at all. Full trace: http://krustophenia.net/testresults.php?dataset=2.6.9-rc1-Q5#/var/www/2.6.9-rc1-Q5/trace5.txt Lee