From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 21 May 2007 18:00:29 +0200 From: Ingo Molnar Subject: Re: [PATCH] mm: swap prefetch improvements Message-ID: <20070521160029.GA28715@elte.hu> References: <20070430162007.ad46e153.akpm@linux-foundation.org> <200705121446.04191.kernel@kolivas.org> <20070521100320.GA1801@elte.hu> <200705212344.27511.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200705212344.27511.kernel@kolivas.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Con Kolivas Cc: Nick Piggin , Ray Lee , ck list , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: * Con Kolivas wrote: > > A suggestion for improvement: right now swap-prefetch does a small > > bit of swapin every 5 seconds and stays idle inbetween. Could this > > perhaps be made more agressive (optionally perhaps), if the system > > is not swapping otherwise? If block-IO level instrumentation is > > needed to determine idleness of block IO then that is justified too > > i think. > > Hmm.. The timer waits 5 seconds before trying to prefetch, but then > only stops if it detects any activity elsewhere. It doesn't actually > try to go idle in between but it doesn't take much activity to put it > back to sleep, hence detecting yet another "not quite idle" period and > then it goes to sleep again. I guess the sleep interval can actually > be changed as another tunable from 5 seconds to whatever the user > wanted. there was nothing else running on the system - so i suspect the swapin activity flagged 'itself' as some 'other' activity and stopped? The swapins happened in 4 bursts, separated by 5 seconds total idleness. Ingo -- 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