From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <47B94D8C.8040605@bull.net> Date: Mon, 18 Feb 2008 10:19:08 +0100 From: Nadia Derbey MIME-Version: 1.0 Subject: Re: [PATCH 1/8] Scaling msgmni to the amount of lowmem References: <20080211141646.948191000@bull.net> <20080211141813.354484000@bull.net> <20080215215916.8566d337.akpm@linux-foundation.org> In-Reply-To: <20080215215916.8566d337.akpm@linux-foundation.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-kernel@vger.kernel.org, y-goto@jp.fujitsu.com, linux-mm@kvack.org, containers@lists.linux-foundation.org, matthltc@us.ibm.com, cmm@us.ibm.com List-ID: Andrew Morton wrote: > On Mon, 11 Feb 2008 15:16:47 +0100 Nadia.Derbey@bull.net wrote: > > >>[PATCH 01/08] >> >>This patch computes msg_ctlmni to make it scale with the amount of lowmem. >>msg_ctlmni is now set to make the message queues occupy 1/32 of the available >>lowmem. >> >>Some cleaning has also been done for the MSGPOOL constant: the msgctl man page >>says it's not used, but it also defines it as a size in bytes (the code >>expresses it in Kbytes). >> > > > Something's wrong here. Running LTP's msgctl08 (specifically: > ltp-full-20070228) cripples the machine. It's a 4-way 4GB x86_64. > > http://userweb.kernel.org/~akpm/config-x.txt > http://userweb.kernel.org/~akpm/dmesg-x.txt > > Normally msgctl08 will complete in a second or two. With this patch I > don't know how long it will take to complete, and the machine is horridly > bogged down. It does recover if you manage to kill msgctl08. Feels like > a terrible memory shortage, but there's plenty of memory free and it isn't > swapping. > > > Before the patchset, msgctl08 used to be run with the old msgmni value: 16. Now it is run with a much higher msgmni value (1746 in my case), since it scales to the memory size. When I call "msgctl08 100000 16" it completes fast. Doing the follwing on the ref kernel: echo 1746 > /proc/sys/kernel/msgmni msgctl08 100000 1746 makes th test block too :-( Will check to see where the problem comes from. Rgards, Nadia -- 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/ . Don't email: email@kvack.org