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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76FCBC433F5 for ; Mon, 7 Mar 2022 03:28:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D48938D0002; Sun, 6 Mar 2022 22:28:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CF80F8D0001; Sun, 6 Mar 2022 22:28:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BE7008D0002; Sun, 6 Mar 2022 22:28:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id B058D8D0001 for ; Sun, 6 Mar 2022 22:28:07 -0500 (EST) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 71A866136B for ; Mon, 7 Mar 2022 03:28:07 +0000 (UTC) X-FDA: 79216156614.13.E1D91E0 Received: from out199-11.us.a.mail.aliyun.com (out199-11.us.a.mail.aliyun.com [47.90.199.11]) by imf24.hostedemail.com (Postfix) with ESMTP id 317BE180005 for ; Mon, 7 Mar 2022 03:28:04 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R441e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04407;MF=dtcccc@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0V6P0CTe_1646623680; Received: from 30.97.48.243(mailfrom:dtcccc@linux.alibaba.com fp:SMTPD_---0V6P0CTe_1646623680) by smtp.aliyun-inc.com(127.0.0.1); Mon, 07 Mar 2022 11:28:00 +0800 Message-ID: <44ba7c68-d2a5-5bc1-b8e1-1a9dc6619369@linux.alibaba.com> Date: Mon, 7 Mar 2022 11:27:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH v2 2/2] kfence: Alloc kfence_pool after system startup Content-Language: en-US From: Tianchen Ding To: Marco Elver Cc: Alexander Potapenko , Dmitry Vyukov , Andrew Morton , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220305144858.17040-1-dtcccc@linux.alibaba.com> <20220305144858.17040-3-dtcccc@linux.alibaba.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 317BE180005 X-Stat-Signature: xpa3syd1wh3p593ogrue4fzyzsfppcgs Authentication-Results: imf24.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf24.hostedemail.com: domain of dtcccc@linux.alibaba.com designates 47.90.199.11 as permitted sender) smtp.mailfrom=dtcccc@linux.alibaba.com X-HE-Tag: 1646623684-959672 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 2022/3/7 10:23, Tianchen Ding wrote: > On 2022/3/7 07:52, Marco Elver wrote: >> On Sat, 5 Mar 2022 at 15:49, Tianchen Ding >> wrote: >> [...] >>> +static int kfence_init_late(void) >>> +{ >>> +       const unsigned long nr_pages = KFENCE_POOL_SIZE / PAGE_SIZE; >>> +       struct page *pages; >>> + >>> +       pages = alloc_contig_pages(nr_pages, GFP_KERNEL, >>> first_online_node, NULL); >> >>> mm/kfence/core.c:836:17: error: implicit declaration of function >>> ‘alloc_contig_pages’ [-Werror=implicit-function-declaration] >> >> This doesn't build without CMA. See ifdef CONFIG_CONTIG_ALLOC in >> gfp.h, which declares alloc_contig_pages. >> >> Will alloc_pages() work as you expect? If so, perhaps only use >> alloc_contig_pages() #ifdef CONFIG_CONTIG_ALLOC. >> > > alloc_pages() will be fine. We could free "tail" pages after inited. > Will send v3 soon. > Oh, I remember why we use alloc_contig_pages()... alloc_pages() (or alloc_pages_exact()) only support pages less than MAX_ORDER (default 11). The alloc would fail when KFENCE_NUM_OBJECTS >= 512. So the design would be: ifndef CONFIG_CONTIG_ALLOC and KFENCE_NUM_OBJECTS exceeds MAX_ORDER, we do not support alloc KFENCE pool after system startup. >> Thanks, >> -- Marco >