From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.phys.uu.nl (max.phys.uu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id AAA04216 for ; Wed, 17 Jun 1998 00:45:58 -0400 Received: from mirkwood.dummy.home (root@anx1p6.phys.uu.nl [131.211.33.95]) by max.phys.uu.nl (8.8.7/8.8.7/hjm) with ESMTP id GAA07347 for ; Wed, 17 Jun 1998 06:45:54 +0200 (MET DST) Received: from localhost (riel@localhost) by mirkwood.dummy.home (8.9.0/8.9.0) with SMTP id AAA06878 for ; Wed, 17 Jun 1998 00:10:08 +0200 Date: Wed, 17 Jun 1998 00:10:07 +0200 (CEST) From: Rik van Riel Reply-To: Rik van Riel Subject: PTE chaining, kswapd and swapin readahead Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Linux MM List-ID: Hi, In the PTE chaining discussion/patches a while ago, I saw that kswapd was changed in a way that it scanned memory in physical order instead of walking the pagetables. This has the advantage of deallocating memory in physically adjecant chunks, which will be nice while we still have the primitive buddy allocator we're using now. However, it will be a major performance bottleneck when we get around to implementing the zone allocator and swapin readahead. This is because we don't need physical deallocation with the zone allocatore and because swapin readahead is just an awful lot faster when the pages are contiguous in swap. I write this to let the PTE people (Stephen and Ben) know that they probably shouldn't remove the pagetable walking routines from kswapd... Rik. +-------------------------------------------------------------------+ | Linux memory management tour guide. H.H.vanRiel@phys.uu.nl | | Scouting Vries cubscout leader. http://www.phys.uu.nl/~riel/ | +-------------------------------------------------------------------+