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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D7845C43457 for ; Tue, 13 Oct 2020 14:43:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A176524887 for ; Tue, 13 Oct 2020 14:43:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730352AbgJMOnj (ORCPT ); Tue, 13 Oct 2020 10:43:39 -0400 Received: from mx2.suse.de ([195.135.220.15]:36866 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726763AbgJMOng (ORCPT ); Tue, 13 Oct 2020 10:43:36 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E0B48AEE5; Tue, 13 Oct 2020 14:43:33 +0000 (UTC) From: Oscar Salvador To: n-horiguchi@ah.jp.nec.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador , Naoya Horiguchi Subject: [PATCH v5 1/4] mm,hwpoison: drain pcplists before bailing out for non-buddy zero-refcount page Date: Tue, 13 Oct 2020 16:44:44 +0200 Message-Id: <20201013144447.6706-2-osalvador@suse.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201013144447.6706-1-osalvador@suse.de> References: <20201013144447.6706-1-osalvador@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A page with 0-refcount and !PageBuddy could perfectly be a pcppage. Currently, we bail out with an error if we encounter such a page, meaning that we do not handle pcppages neither from hard-offline nor from soft-offline path. Fix this by draining pcplists whenever we find this kind of page and retry the check again. It might be that pcplists have been spilled into the buddy allocator and so we can handle it. Signed-off-by: Oscar Salvador Acked-by: Naoya Horiguchi --- mm/memory-failure.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index c0bb186bba62..e2f12410c594 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -946,13 +946,13 @@ static int page_action(struct page_state *ps, struct page *p, } /** - * get_hwpoison_page() - Get refcount for memory error handling: + * __get_hwpoison_page() - Get refcount for memory error handling: * @page: raw error page (hit by memory error) * * Return: return 0 if failed to grab the refcount, otherwise true (some * non-zero value.) */ -static int get_hwpoison_page(struct page *page) +static int __get_hwpoison_page(struct page *page) { struct page *head = compound_head(page); @@ -982,6 +982,26 @@ static int get_hwpoison_page(struct page *page) return 0; } +static int get_hwpoison_page(struct page *p) +{ + int ret; + bool drained = false; + +retry: + ret = __get_hwpoison_page(p); + if (!ret && !is_free_buddy_page(p) && !page_count(p) && !drained) { + /* + * The page might be in a pcplist, so try to drain those + * and see if we are lucky. + */ + drain_all_pages(page_zone(p)); + drained = true; + goto retry; + } + + return ret; +} + /* * Do all that is necessary to remove user space mappings. Unmap * the pages and send SIGBUS to the processes if the data was dirty. -- 2.26.2