From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from digeo-nav01.digeo.com (digeo-nav01.digeo.com [192.168.1.233]) by packet.digeo.com (8.9.3+Sun/8.9.3) with SMTP id BAA21118 for ; Fri, 14 Feb 2003 01:57:39 -0800 (PST) Date: Fri, 14 Feb 2003 01:58:02 -0800 From: Andrew Morton Subject: Re: 2.5.60-mm2 Message-Id: <20030214015802.66800166.akpm@digeo.com> In-Reply-To: <20030214093856.GC13845@codemonkey.org.uk> References: <20030214013144.2d94a9c5.akpm@digeo.com> <20030214093856.GC13845@codemonkey.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Jones Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Dave Jones wrote: > > On Fri, Feb 14, 2003 at 01:31:44AM -0800, Andrew Morton wrote: > > > . Considerable poking at the NFS MAP_SHARED OOM lockup. It is limping > > along now, but writeout bandwidth is poor and it is still struggling. > > Needs work. > > > > . There's a one-liner which removes an O(n^2) search in the NFS writeback > > path. It increases writeout bandwidth by 4x and decreases CPU load from > > 100% to 3%. Needs work. > > I'm puzzled that you've had NFS stable enough to test these. This was just writing out a single 400 megabyte file with `dd'. I didn't try anything fancier. > How much testing has this stuff had? Here 2.5.60+bk clients fall over under > moderate NFS load. (And go splat quickly under high load). > > Trying to run things like dbench causes lockups, fsx/fstress made it > reboot, plus the odd 'cheating' errors reported yesterday. I have not tried pushing NFS with complex access patterns recently. BTW, there's a little patch in there from Trond which I forgot to mention: it implements sendfile for NFS, so loop-on-NFS works again. But we have a refcounting bug somewhere: # mount server:/dir /mnt/point # losetup /dev/loop0 /mnt/point/file # mount /dev/loop0 /mnt/loop0 # umount /mnt/loop0 # losetup -d /dev/loop0 # umount /mnt/point umount: /mnt/point: device is busy -- 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: aart@kvack.org