From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id DC9CC6B016A for ; Thu, 25 Aug 2011 22:16:52 -0400 (EDT) Date: Fri, 26 Aug 2011 10:16:48 +0800 From: Wu Fengguang Subject: Re: slow performance on disk/network i/o full speed after drop_caches Message-ID: <20110826021648.GA19529@localhost> References: <4E5494D4.1050605@profihost.ag> <4E54BDCF.9020504@profihost.ag> <20110824093336.GB5214@localhost> <4E560F2A.1030801@profihost.ag> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E560F2A.1030801@profihost.ag> Sender: owner-linux-mm@kvack.org List-ID: To: Stefan Priebe - Profihost AG Cc: Pekka Enberg , LKML , "linux-mm@kvack.org" , Andrew Morton , Mel Gorman , Jens Axboe , Linux Netdev List Hi Stefan, > Here is the data you requested: > > root@server1015-han:~# grep . /sys/devices/system/node/node*/vmstat > /sys/devices/system/node/node0/vmstat:nr_written 5546561 > /sys/devices/system/node/node0/vmstat:nr_dirtied 5572497 > /sys/devices/system/node/node1/vmstat:nr_written 3936 > /sys/devices/system/node/node1/vmstat:nr_dirtied 4190 Ah you are running an older kernel that didn't show all the vmstat numbers. But still it's revealing that node 0 is used heavily and node 1 is almost idle. So I won't be surprised to see most free pages lie in node 1. > modified it a little bit: > ~# while [ true ]; do ps -eo > user,pid,tid,class,rtprio,ni,pri,psr,pcpu,vsz,rss,pmem,stat,wchan:28,cmd > | grep scp | grep -v grep; sleep 1; done > > root 12409 12409 TS - 0 19 0 59.8 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ It's mostly doing poll() waits. There must be some dependency on something other to make progress. Would you post the full ps output for all tasks, and even better, run echo t > /proc/sysrq-trigger To dump the kernel stacks? Thanks, Fengguang > root 12409 12409 TS - 0 19 0 64.0 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 0 67.7 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 8 70.6 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 8 73.5 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 8 76.0 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 8 78.2 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 8 80.0 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 8 80.9 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 2 76.7 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 75.6 42136 1724 0.0 Ds > pipe_read scp -t /tmp/ > root 12409 12409 TS - 0 19 0 76.0 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 1 75.2 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 1 76.6 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 1 77.9 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 1 79.0 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 72.8 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 0 73.0 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 0 73.8 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 74.3 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 73.4 42136 1724 0.0 Ss > - scp -t /tmp/ > root 12409 12409 TS - 0 19 1 71.3 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 71.9 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 0 72.7 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 3 73.5 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 3 74.4 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 3 75.2 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 0 76.0 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 8 76.6 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 74.8 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 73.2 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 1 73.9 42136 1724 0.0 Rs > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 0 72.4 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 8 72.0 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 8 72.5 42136 1724 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12409 12409 TS - 0 19 8 72.9 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12409 12409 TS - 0 19 8 73.5 42136 1724 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 0.0 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 23.0 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 49.5 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 2 63.3 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 71.5 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 77.4 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 70.3 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 73.1 42136 1728 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12566 12566 TS - 0 19 0 65.7 42136 1728 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > root 12566 12566 TS - 0 19 1 61.2 42136 1728 0.0 Ss > - scp -t /tmp/ > root 12566 12566 TS - 0 19 1 63.7 42136 1728 0.0 Rs > - scp -t /tmp/ > root 12636 12636 TS - 0 19 8 0.0 42136 1728 0.0 Ss > poll_schedule_timeout scp -t /tmp/ > > > Stefan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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