From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8609BC41514 for ; Wed, 31 Jul 2019 09:06:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CDF0208C3 for ; Wed, 31 Jul 2019 09:06:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564564017; bh=MJVPGw+WNNAbTwYU58W0WuGORWLiQxMEq7DGkp8uDEw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=nfHOK5QecJTfNtXKlyTNo2dyGVhwWTgSpEHafT6VvJKWPoGkiHO4kFeABR8a2EJdl HAMp5oRcDZK0IEF2o1VS5gVMyRWX1nu6huwbX2CZh2GWaubwy7xiD3dPRPVLkDHE37 CFJbCY5viUGd4/rJgB6ioI/+Ufc/Of+cWR5hzWYE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728373AbfGaJG4 (ORCPT ); Wed, 31 Jul 2019 05:06:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:40264 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726707AbfGaJGz (ORCPT ); Wed, 31 Jul 2019 05:06:55 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 90E14ABE9; Wed, 31 Jul 2019 09:06:54 +0000 (UTC) Date: Wed, 31 Jul 2019 11:06:53 +0200 From: Michal Hocko To: Andrew Morton Cc: Catalin Marinas , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Matthew Wilcox , Qian Cai Subject: Re: [PATCH v2] mm: kmemleak: Use mempool allocations for kmemleak objects Message-ID: <20190731090653.GD9330@dhcp22.suse.cz> References: <20190727132334.9184-1-catalin.marinas@arm.com> <20190730125743.113e59a9c449847d7f6ae7c3@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190730125743.113e59a9c449847d7f6ae7c3@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 30-07-19 12:57:43, Andrew Morton wrote: > On Sat, 27 Jul 2019 14:23:33 +0100 Catalin Marinas wrote: > > > Add mempool allocations for struct kmemleak_object and > > kmemleak_scan_area as slightly more resilient than kmem_cache_alloc() > > under memory pressure. Additionally, mask out all the gfp flags passed > > to kmemleak other than GFP_KERNEL|GFP_ATOMIC. > > > > A boot-time tuning parameter (kmemleak.mempool) is added to allow a > > different minimum pool size (defaulting to NR_CPUS * 4). > > Why would anyone ever want to alter this? Is there some particular > misbehaviour which this will improve? If so, what is it? I do agree with Andrew here. Can we simply go with no tunning for now and only add it based on some real life reports that the auto-tuning is not sufficient? -- Michal Hocko SUSE Labs