From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 28 Jul 2008 19:57:13 -0400 From: Rik van Riel Subject: Re: PERF: performance tests with the split LRU VM in -mm Message-ID: <20080728195713.42cbceed@cuia.bos.redhat.com> In-Reply-To: <20080728164124.8240eabe.akpm@linux-foundation.org> References: <20080724222510.3bbbbedc@bree.surriel.com> <20080728105742.50d6514e@cuia.bos.redhat.com> <20080728164124.8240eabe.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Mon, 28 Jul 2008 16:41:24 -0700 Andrew Morton wrote: > > Andrew, what is your preference between: > > http://lkml.org/lkml/2008/7/15/465 > > and > > http://marc.info/?l=linux-mm&m=121683855132630&w=2 > > > > Boy. They both seem rather hacky special-cases. But that doesn't mean > that they're undesirable hacky special-cases. I guess the second one > looks a bit more "algorithmic" and a bit less hacky-special-case. But > it all depends on testing.. I prefer the second one, since it removes the + 1 magic (at least, for the higher priorities), instead of adding new magic like the other patch does. > On a different topic, these: > > vmscan-give-referenced-active-and-unmapped-pages-a-second-trip-around-the-lru.patch > vm-dont-run-touch_buffer-during-buffercache-lookups.patch > > have been floating about in -mm for ages, awaiting demonstration that > they're a net benefit. But all of this new page-reclaim rework was > built on top of those two patches and incorporates and retains them. > > I could toss them out, but that would require some rework and would > partially invalidate previous testing and who knows, they _might_ be > good patches. Or they might not be. > > What are your thoughts? I believe you should definately keep those. Being able to better preserve actively accessed file pages could be a good benefit and we have yet to discover a downside to those patches. -- All Rights Reversed -- 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