From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261973AbTD3DHA (ORCPT ); Tue, 29 Apr 2003 23:07:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261995AbTD3DHA (ORCPT ); Tue, 29 Apr 2003 23:07:00 -0400 Received: from holomorphy.com ([66.224.33.161]:16592 "EHLO holomorphy") by vger.kernel.org with ESMTP id S261973AbTD3DG7 (ORCPT ); Tue, 29 Apr 2003 23:06:59 -0400 Date: Tue, 29 Apr 2003 20:19:14 -0700 From: William Lee Irwin III To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: Re: must-fix list for 2.6.0 Message-ID: <20030430031914.GC8978@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Andrew Morton , linux-kernel@vger.kernel.org References: <20030429155731.07811707.akpm@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030429155731.07811707.akpm@digeo.com> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 29, 2003 at 03:57:31PM -0700, Andrew Morton wrote: > mm/ > --- > - Overcommit accounting gets wrong answers > - underestimates reclaimable slab, gives bogus failures when > dcache&icache are large. > - gets confused by reclaimable-but-not-freed truncated ext3 pages. > Lame fix exists in -mm. > - Proper user level no overcommit also requires a root margin adding I didn't notice anything specific here about sys_remap_file_pages() vs. truncate() (sans objrmap); did a fix fly by that I didn't notice, or was it less of an issue than I thought it was? Also, the OOM killer fails to check lowmem; basically it just needs - if (nr_swap_pages > 0) + if (nr_swap_pages > 0 && nr_free_buffer_pages() > 0) With that in addition to the OOM killer locking patch I posted and another to completely eliminate mm-less processes from consideration 64GB ia32 (with, of course, my oversized out-of-tree patch) recovers from OOM instead of deadlocking after a mass-killing with swap online. Not that I'd consider 64GB ia32 a supported platform for 2.5/2.6 (it's a design limitation IMHO); it merely "stresses the OOM killer harder" for the purposes of this discussion. Some kind of investigation is probably needed to determine why eliminating mm-less processes from consideration is necessary to obtain the desired behavior. I'd be interested in more detailed descriptions of the user-level no overcommit, dcacheicache, and truncated ext3 page issues after Thursday. On Tue, Apr 29, 2003 at 03:57:31PM -0700, Andrew Morton wrote: > mm/ > --- > - objrmap: concerns over page reclaim performance at high sharing levels, > and interoperation with nonlinear mappings is hairy. > - Readd and make /proc/sys/vm/freepages writable again so that boxes can be > tuned for heavy interrupt load. The latter sounds easy to address. It actually sounds like a 2.4.x compatibility fix. -- wli