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 5144DC433F5 for ; Thu, 3 Mar 2022 03:15:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B237E8D0002; Wed, 2 Mar 2022 22:15:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AD39D8D0001; Wed, 2 Mar 2022 22:15:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C08D8D0002; Wed, 2 Mar 2022 22:15:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 8A7138D0001 for ; Wed, 2 Mar 2022 22:15:19 -0500 (EST) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 5AE8F60974 for ; Thu, 3 Mar 2022 03:15:19 +0000 (UTC) X-FDA: 79201609158.04.80C72F0 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by imf22.hostedemail.com (Postfix) with ESMTP id AE64FC0003 for ; Thu, 3 Mar 2022 03:15:17 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R931e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04357;MF=dtcccc@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0V650kF3_1646277305; Received: from localhost.localdomain(mailfrom:dtcccc@linux.alibaba.com fp:SMTPD_---0V650kF3_1646277305) by smtp.aliyun-inc.com(127.0.0.1); Thu, 03 Mar 2022 11:15:14 +0800 From: Tianchen Ding To: Alexander Potapenko , Marco Elver , Dmitry Vyukov , Andrew Morton Cc: kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 0/2] Alloc kfence_pool after system startup Date: Thu, 3 Mar 2022 11:15:03 +0800 Message-Id: <20220303031505.28495-1-dtcccc@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: AE64FC0003 X-Stat-Signature: z4zzoexzdddisqzqpu15a7sihwy81pis X-Rspam-User: Authentication-Results: imf22.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf22.hostedemail.com: domain of dtcccc@linux.alibaba.com designates 115.124.30.133 as permitted sender) smtp.mailfrom=dtcccc@linux.alibaba.com X-Rspamd-Server: rspam03 X-HE-Tag: 1646277317-264029 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: KFENCE aims at production environments, but it does not allow enabling after system startup because kfence_pool only alloc pages from memblock. Consider the following production scene: At first, for performance considerations, production machines do not enable KFENCE. However, after running for a while, the kernel is suspected to have memory errors. (e.g., a sibling machine crashed.) So other production machines need to enable KFENCE, but it's hard for them to reboot. The 1st patch allows re-enabling KFENCE if the pool is already allocated from memblock. The 2nd patch applies the main part. Tianchen Ding (2): kfence: Allow re-enabling KFENCE after system startup kfence: Alloc kfence_pool after system startup mm/kfence/core.c | 106 ++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 87 insertions(+), 19 deletions(-) -- 2.27.0