Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261641AbUJ0FEl (ORCPT ); Wed, 27 Oct 2004 01:04:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261642AbUJ0FEl (ORCPT ); Wed, 27 Oct 2004 01:04:41 -0400 Received: from mail-relay-1.tiscali.it ([213.205.33.41]:47493 "EHLO mail-relay-1.tiscali.it") by vger.kernel.org with ESMTP id S261641AbUJ0FEj (ORCPT ); Wed, 27 Oct 2004 01:04:39 -0400 Date: Wed, 27 Oct 2004 07:05:27 +0200 From: Andrea Arcangeli To: Rik van Riel Cc: Andrew Morton , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: lowmem_reserve (replaces protection) Message-ID: <20041027050527.GW14325@dualathlon.random> References: <20041027044445.GV14325@dualathlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1269 Lines: 26 On Wed, Oct 27, 2004 at 12:51:11AM -0400, Rik van Riel wrote: > On Wed, 27 Oct 2004, Andrea Arcangeli wrote: > > > what we'll happen is that we'll blindly free a few pages from each zone, > > but then we'll be allowed to allocate the highmem pages, and not the > > normal/dma pages. So after allocating the highmem pages we invoke kswapd > > again and it frees again some highmem/normal/dma pages but we keep only > > using the highmem ones. So for a while we may be rolling over only the > > highmem lru and ignoring all freed pages from the normal/dma zones. > > This is not how the page allocator in 2.6 works. > > It will not wake up kswapd until it is past the low > watermark in all zones. how else the page allocator should work if not waiting all zones to hit the low+reserve watermarks? the page allocator works the same in 2.4 and 2.6, so I don't understand your point. what changes is kswapd stop algorithm and the fact the lru is per-zone, but I think I described correctly what happens in 2.6 kswapd-stop. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/