From mboxrd@z Thu Jan 1 00:00:00 1970 From: Con Kolivas Subject: Re: [PATCH] mm: swap prefetch improvements Date: Sat, 12 May 2007 18:21:47 +1000 References: <20070430162007.ad46e153.akpm@linux-foundation.org> <200705121728.34987.kernel@kolivas.org> <20070512011454.50ba68a5.pj@sgi.com> In-Reply-To: <20070512011454.50ba68a5.pj@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200705121821.48515.kernel@kolivas.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Jackson Cc: nickpiggin@yahoo.com.au, ray-lk@madrabbit.org, mingo@elte.hu, ck@vds.kolivas.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Saturday 12 May 2007 18:14, Paul Jackson wrote: > > Ummm this is what I've been saying for over a year now but noone has been > > listening. > > Well ... if there is a problem using prefetch and cpusets together, > it doesn't look like the two of us are going to find it. > > I should probably look at your patch to answer this next question, > but being a lazy retard, I'll just ask. Is there a way, on a running > system that has your prefetch patch configured in, to disable prefetch > -- perhaps writing to some magic /proc file or something? Indeed: /proc/sys/vm/swap_prefetch > If so, then how about you just remove the lines in the patch that > disable prefetch on kernels configured with CPUSETS, and we charge > ahead allowing both at the same time? Ok so change the default value for swap_prefetch to 0 when CPUSETS is enabled? Sure, I can do that. > If some day in the future I find something about prefetch that harms > the HPC NUMA loads I care about, then I can just dynamically disable > prefetch. > > If someone ever uncovers a real problem with prefetch and cpusets, > then we will deal with it then. > > As to whether your patch is otherwise (other than cpusets) worthy > of further acceptance, that I will have to leave up to those who are > competent to make such judgements. Thank you very much for your comments! -- -ck -- 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