From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 075A66B016A for ; Thu, 25 Aug 2011 23:26:05 -0400 (EDT) Date: Fri, 26 Aug 2011 11:26:02 +0800 From: Wu Fengguang Subject: Re: slow performance on disk/network i/o full speed after drop_caches Message-ID: <20110826032601.GA26282@localhost> References: <4E5494D4.1050605@profihost.ag> <4E54BDCF.9020504@profihost.ag> <20110824093336.GB5214@localhost> <4E560F2A.1030801@profihost.ag> <20110826021648.GA19529@localhost> <4E570AEB.1040703@profihost.ag> <20110826030313.GA24058@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Stefan Priebe Cc: Pekka Enberg , LKML , "linux-mm@kvack.org" , Andrew Morton , Mel Gorman , Jens Axboe , Linux Netdev List On Fri, Aug 26, 2011 at 11:13:07AM +0800, Stefan Priebe wrote: > > >> There is at least a numastat proc file. > > > > Thanks. This shows that node0 is accessed 10x more than node1. > > What can i do to prevent this or isn't this normal when a machine mostly idles so processes are mostly processed by cpu0. Yes, that's normal. However it should explain why it's slow even when there are lots of free pages _globally_. > > > >> complete ps output: > >> http://pastebin.com/raw.php?i=b948svzN > > > > In that log, scp happens to be in R state and also no other tasks in D > > state. Would you retry in the hope of catching some stucked state? > Sadly not as the sysrq trigger has rebootet the machine and it will now run fine for 1 or 2 days. Oops, sorry! It might be possible to reproduce the issue by manually eating all of the memory with sparse file data: truncate -s 1T 1T cp 1T /dev/null > > > >>> echo t> /proc/sysrq-trigger > >> sadly i wa sonly able to grab the output in this crazy format: > >> http://pastebin.com/raw.php?i=MBXvvyH1 > > > > It's pretty readable dmesg, except that the data is incomplete and > > there are nothing valuable in the uploaded portion.. > That was everything i could grab through netconsole. Is there a better way? netconsole is enough. The partial output should be due to the reboot... Thanks, Fengguang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org