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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 6CF9AC31E40 for ; Mon, 12 Aug 2019 21:07:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2D76B20842 for ; Mon, 12 Aug 2019 21:07:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="KSc2f7WJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D76B20842 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B94B56B0003; Mon, 12 Aug 2019 17:07:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B448B6B0005; Mon, 12 Aug 2019 17:07:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A59D76B0006; Mon, 12 Aug 2019 17:07:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 838CD6B0003 for ; Mon, 12 Aug 2019 17:07:33 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 3ABA2181AC9AE for ; Mon, 12 Aug 2019 21:07:33 +0000 (UTC) X-FDA: 75815011986.07.sleet73_7af3f2b70e13 X-HE-Tag: sleet73_7af3f2b70e13 X-Filterd-Recvd-Size: 2690 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Mon, 12 Aug 2019 21:07:32 +0000 (UTC) Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 75159206C2; Mon, 12 Aug 2019 21:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565644051; bh=8eWu0FeEigtryjeLkybywbMKb9yID/F2+1F7HYeW6MM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=KSc2f7WJ+aVJbY03uw3UilWLAtizXPAUmMYG3sHCkIFvvCmev13bVOmzlC7c9DVvu TeJWhQV7OhPUJ2Tp8JQEIgR7dRP5f1Cy44CsuUM+mAdfmg1cwNi5yByYYrqsdtng6l 6qQ6wmggXbxoq8GT9R4qXV42gFqJDwD+b6ejhFnw= Date: Mon, 12 Aug 2019 14:07:30 -0700 From: Andrew Morton To: Catalin Marinas Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Matthew Wilcox , Qian Cai Subject: Re: [PATCH v3 0/3] mm: kmemleak: Use a memory pool for kmemleak object allocations Message-Id: <20190812140730.71dd7f35d568b4d8530f8908@linux-foundation.org> In-Reply-To: <20190812160642.52134-1-catalin.marinas@arm.com> References: <20190812160642.52134-1-catalin.marinas@arm.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 12 Aug 2019 17:06:39 +0100 Catalin Marinas wrote: > Following the discussions on v2 of this patch(set) [1], this series > takes slightly different approach: > > - it implements its own simple memory pool that does not rely on the > slab allocator > > - drops the early log buffer logic entirely since it can now allocate > metadata from the memory pool directly before kmemleak is fully > initialised > > - CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE option is renamed to > CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE > > - moves the kmemleak_init() call earlier (mm_init()) > > - to avoid a separate memory pool for struct scan_area, it makes the > tool robust when such allocations fail as scan areas are rather an > optimisation > > [1] http://lkml.kernel.org/r/20190727132334.9184-1-catalin.marinas@arm.com Using the term "memory pool" is a little unfortunate, but better than using "mempool"! The changelog doesn't answer the very first question: why not use mempools. Please send along a paragraph which explains this decision.