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=-10.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EE24FC47089 for ; Thu, 27 May 2021 08:22:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9268F611CD for ; Thu, 27 May 2021 08:22:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9268F611CD Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2D15F6B0071; Thu, 27 May 2021 04:22:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2A6F86B0072; Thu, 27 May 2021 04:22:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 16E9A6B0073; Thu, 27 May 2021 04:22:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id D687C6B0071 for ; Thu, 27 May 2021 04:22:25 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 7BD05841B for ; Thu, 27 May 2021 08:22:25 +0000 (UTC) X-FDA: 78186319050.22.B5D9658 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf18.hostedemail.com (Postfix) with ESMTP id 17D3420007E0 for ; Thu, 27 May 2021 08:22:17 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1622103744; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+EfkVrIQZXBeZTPSxjNuEm8wUQKfD3cTZZ/zTTMSBzw=; b=iIdOJB9ZclOzK1R83f55YqiC+wO2fih/GoA1P6TTFS7h/zJZv+/vjHUezFzt6uULVaRUNQ eLiBhU2Vt0rRbhtKjqCzvjWLKXmuXfKoUvniad9b6jcJksXd04jGHck9f8MPt9I054mw0y VQ+IuJWWlJzLeN4HCvmS7MSB1NRuQbw= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1F646AB71; Thu, 27 May 2021 08:22:24 +0000 (UTC) Date: Thu, 27 May 2021 10:22:23 +0200 From: Michal Hocko To: Oscar Salvador Cc: Naoya Horiguchi , linux-mm@kvack.org, Mike Kravetz , Muchun Song , Andrew Morton , David Hildenbrand , Naoya Horiguchi , linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] hugetlb: pass head page to remove_hugetlb_page() Message-ID: References: <20210526235257.2769473-1-nao.horiguchi@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=iIdOJB9Z; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf18.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Stat-Signature: 6d6tbbszg1dz75xdg9gwqwo1pfnubxm4 X-Rspamd-Queue-Id: 17D3420007E0 X-Rspamd-Server: rspam02 X-HE-Tag: 1622103737-937773 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 Thu 27-05-21 09:47:44, Oscar Salvador wrote: > On Thu, May 27, 2021 at 08:52:57AM +0900, Naoya Horiguchi wrote: > > From: Naoya Horiguchi > > > > When memory_failure() or soft_offline_page() is called on a tail page of > > some hugetlb page, "BUG: unable to handle page fault" error can be > > triggered. > > > > remove_hugetlb_page() dereferences page->lru, so it's assumed that the > > page points to a head page, but one of the caller, > > dissolve_free_huge_page(), provides remove_hugetlb_page() with 'page' > > which could be a tail page. So pass 'head' to it, instead. > > > > Fixes: 6eb4e88a6d27 ("hugetlb: create remove_hugetlb_page() to separate functionality") > > Signed-off-by: Naoya Horiguchi > > Reviewed-by: Oscar Salvador > > It is probably worth adding a comment in remove_hugetlb_page() noting > that we need a head page, so future users do not repeat the same > mistake. Ideally this will turn into page folio concept and no comments are really needed. -- Michal Hocko SUSE Labs