Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755033AbYAIJiQ (ORCPT ); Wed, 9 Jan 2008 04:38:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753472AbYAIJhy (ORCPT ); Wed, 9 Jan 2008 04:37:54 -0500 Received: from mga10.intel.com ([192.55.52.92]:25740 "EHLO fmsmga102.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753381AbYAIJhw (ORCPT ); Wed, 9 Jan 2008 04:37:52 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.24,261,1196668800"; d="scan'208";a="490805146" Subject: Netperf TCP_RR(loopback) 10% regression in 2.6.24-rc6, comparing with 2.6.22 From: "Zhang, Yanmin" To: LKML Content-Type: text/plain; charset=utf-8 Date: Wed, 09 Jan 2008 17:35:30 +0800 Message-Id: <1199871330.3298.132.camel@ymzhang> Mime-Version: 1.0 X-Mailer: Evolution 2.9.2 (2.9.2-2.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2500 Lines: 55 The regression is: 1)stoakley with 2 qual-core processors: 11%; 2)Tulsa with 4 dual-core(+hyperThread) processors:13%; The test command is: #sudo taskset -c 7 ./netserver #sudo taskset -c 0 ./netperf -t TCP_RR -l 60 -H 127.0.0.1 -i 50,3 -I 99,5 -- -r 1,1 As a matter of fact, 2.6.23 has about 6% regression and 2.6.24-rc's regression is between 16%~11%. I tried to use bisect to locate the bad patch between 2.6.22 and 2.6.23-rc1, but the bisected kernel wasn't stable and went crazy. I tried both CONFIG_SLUB=y and CONFIG_SLAB=y to make sure SLUB isn't the culprit. The oprofile data of CONFIG_SLAB=y. Top cpu utilizations are: 1) 2.6.22 2067379 9.4888 vmlinux schedule 1873604 8.5994 vmlinux mwait_idle 1568131 7.1974 vmlinux resched_task 1066976 4.8972 vmlinux tcp_v4_rcv 986641 4.5285 vmlinux tcp_rcv_established 979518 4.4958 vmlinux find_busiest_group 767069 3.5207 vmlinux sock_def_readable 736808 3.3818 vmlinux tcp_sendmsg 595889 2.7350 vmlinux task_rq_lock 557193 2.5574 vmlinux tcp_ack 470570 2.1598 vmlinux __mod_timer 392220 1.8002 vmlinux __alloc_skb 358106 1.6436 vmlinux skb_release_data 313372 1.4383 vmlinux skb_clone 2) 2.6.24-rc7 2668426 12.4497 vmlinux vmlinux schedule 955698 4.4589 vmlinux vmlinux skb_release_data 836311 3.9018 vmlinux vmlinux tcp_v4_rcv 762398 3.5570 vmlinux vmlinux skb_release_all 728907 3.4007 vmlinux vmlinux task_rq_lock 705037 3.2894 vmlinux vmlinux __wake_up 694206 3.2388 vmlinux vmlinux __mod_timer 617616 2.8815 vmlinux vmlinux mwait_idle It looks like tcp in 2.6.22 sends more packets, but frees far less skb than 2.6.24-rc6. tcp_rcv_established in 2.6.22 is highlighted on cpu utilization. -yanmin -- 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/