From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 6/9] clockpro-clockpro.patch From: Peter Zijlstra In-Reply-To: <20051231224021.GA5184@dmt.cnet> References: <20051230223952.765.21096.sendpatchset@twins.localnet> <20051230224312.765.58575.sendpatchset@twins.localnet> <20051231224021.GA5184@dmt.cnet> Content-Type: text/plain Date: Sun, 01 Jan 2006 11:37:34 +0100 Message-Id: <1136111854.17853.77.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Christoph Lameter , Wu Fengguang , Nick Piggin , Marijn Meijles , Rik van Riel List-ID: On Sat, 2005-12-31 at 20:40 -0200, Marcelo Tosatti wrote: > On Fri, Dec 30, 2005 at 11:43:34PM +0100, Peter Zijlstra wrote: > > > > From: Peter Zijlstra > > Peter, > > I tried your "scan-shared.c" proggy which loops over 140M of a file > using mmap (on a 128MB box). The number of loops was configured to "5". > > The amount of major/minor pagefaults was exactly the same between > vanilla and clockpro, isnt the clockpro algorithm supposed to be > superior than LRU in such "sequential scan of MEMSIZE+1" cases? yes it should, hmm, have to look at that then. What should happen is that nr_cold_target should drop to the bare minimum, which effectivly pins all hot pages and only rotates the few cold pages. > Oh well, to be sincere, I still haven't understood what makes CLOCK-Pro > use inter reference distance instead of recency, given that its a simple > CLOCK using reference bits (but with three clocks instead of one). > > But thats probably just my ignorance, need to study more. The reuse distance is in PG_test. Please see the clockpro-documentation patch, which should explain this. If its still not clear after that let me know, I'll be more verbose then. -- Peter Zijlstra -- 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