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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 D02B8C04AB5 for ; Mon, 3 Jun 2019 14:35:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B00EB27A8E for ; Mon, 3 Jun 2019 14:35:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729033AbfFCOfN (ORCPT ); Mon, 3 Jun 2019 10:35:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:54862 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728998AbfFCOfN (ORCPT ); Mon, 3 Jun 2019 10:35:13 -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 EC697ACCE; Mon, 3 Jun 2019 14:35:11 +0000 (UTC) From: Vlastimil Babka To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Andrew Morton , "Kirill A. Shutemov" , Michal Hocko , Vlastimil Babka , Joonsoo Kim , Matthew Wilcox , Mel Gorman Subject: [PATCH 0/3] debug_pagealloc improvements Date: Mon, 3 Jun 2019 16:34:48 +0200 Message-Id: <20190603143451.27353-1-vbabka@suse.cz> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I have been recently debugging some pcplist corruptions, where it would be useful to perform struct page checks immediately as pages are allocated from and freed to pcplists, which is now only possible by rebuilding the kernel with CONFIG_DEBUG_VM (details in Patch 2 changelog). To make this kind of debugging simpler in future on a distro kernel, I have improved CONFIG_DEBUG_PAGEALLOC so that it has even smaller overhead when not enabled at boot time (Patch 1) and also when enabled (Patch 3), and extended it to perform the struct page checks more often when enabled (Patch 2). Now it can be configured in when building a distro kernel without extra overhead, and debugging page use after free or double free can be enabled simply by rebooting with debug_pagealloc=on. Vlastimil Babka (3): mm, debug_pagelloc: use static keys to enable debugging mm, page_alloc: more extensive free page checking with debug_pagealloc mm, debug_pagealloc: use a page type instead of page_ext flag .../admin-guide/kernel-parameters.txt | 10 +- include/linux/mm.h | 25 ++-- include/linux/page-flags.h | 6 + include/linux/page_ext.h | 1 - mm/Kconfig.debug | 14 ++- mm/page_alloc.c | 114 ++++++++++-------- mm/page_ext.c | 3 - 7 files changed, 96 insertions(+), 77 deletions(-) -- 2.21.0