From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 13 Oct 2004 20:20:41 -0700 From: Andrew Morton Subject: Re: Page cache write performance issue Message-Id: <20041013202041.2e7066af.akpm@osdl.org> In-Reply-To: <20041014005300.GA716@frodo> References: <20041013054452.GB1618@frodo> <20041012231945.2aff9a00.akpm@osdl.org> <20041013063955.GA2079@frodo> <20041013000206.680132ad.akpm@osdl.org> <20041013172352.B4917536@wobbly.melbourne.sgi.com> <416CE423.3000607@cyberone.com.au> <20041013013941.49693816.akpm@osdl.org> <20041014005300.GA716@frodo> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nathan Scott Cc: piggin@cyberone.com.au, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@oss.sgi.com List-ID: Nathan Scott wrote: > > On Wed, Oct 13, 2004 at 01:39:41AM -0700, Andrew Morton wrote: > > Nick Piggin wrote: > > > > > > Andrew probably has better ideas. > > > > uh, is this an ia32 highmem box? > > Yep, it is. > > > If so, you've hit the VM sour spot. > > ... > > Basically, *any* other config is fine. 896MB and below, 1.5GB and above. > > I just tried switching CONFIG_HIGHMEM off, and so running the > machine with 512MB; then adjusted the test to write 256M into > the page cache, again in 1K sequential chunks. A similar mis- > behaviour happens, though the numbers are slightly better (up > from ~4 to ~6.5MB/sec). Both ext2 and xfs see this. When I > drop the file size down to 128M with this kernel, I see good > results again (as we'd expect). No such problem here, with dd if=/dev/zero of=x bs=1k count=128k on a 256MB machine. xfs and ext2. Can you exhibit this one more than one machine? Silly question: what does `grep sync' /etc/fstab say over there? ;) -- 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