From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 06 Jan 2006 18:01:35 +0900 From: IWAMOTO Toshihiro Subject: Re: [PATCH 6/9] clockpro-clockpro.patch In-Reply-To: References: <20051230223952.765.21096.sendpatchset@twins.localnet> <20051230224312.765.58575.sendpatchset@twins.localnet> <20051231002417.GA4913@dmt.cnet> <1136028546.17853.69.camel@twins> <20060105094722.897C574030@sv1.valinux.co.jp> MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Message-Id: <20060106090135.3525D74031@sv1.valinux.co.jp> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: IWAMOTO Toshihiro , Peter Zijlstra , Marcelo Tosatti , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Christoph Lameter , Wu Fengguang , Nick Piggin , Marijn Meijles List-ID: At Thu, 5 Jan 2006 08:32:19 -0500 (EST), Rik van Riel wrote: > > On Thu, 5 Jan 2006, IWAMOTO Toshihiro wrote: > > In my understanding of CLOCK-Pro, such lapping causes sudden increase > > in the distance between Hhot and Hcold. As that distance is an > > important parameter of page aging/replacement decisions, I'm afraid > > that such lapping would result in incorrect page aging and bad > > performance. > > Hcold only manipulates cold pages, Hhot only manipulates hot > pages and the test bit on cold pages. Having one hand overtake > the other should not disturb things at all, since they both do > something different. I don't think so. Hhot turns unreferenced hot pages into cold ones, and those are freed if they aren't referenced before Hcold passes. So, the distance between those hands is a sort of "expiry timer" of such pages. The distance also affects aging of newly inserted pages. -- IWAMOTO Toshihiro -- 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