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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 92D8ECA9EA0 for ; Fri, 18 Oct 2019 11:48:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63DD520700 for ; Fri, 18 Oct 2019 11:48:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571399316; bh=idJrDIQCpgFChGbt+UHdm83yNIaMd7O80kxnumL0Ejg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=GJO5Z9NFjCjptgAL6oHygCKmZMmQ0by3tTfdPtX693qUwcsjEnoWeBhprE14WKuOo V8ss1er1GZYGRC4RchTNAlnYMDaS4/EEJmos0L4ciPt51x3mowumD8qTzZL1T8shfR R7rtCTuJ2jyM3mMQYOZIYpKfMGRS+panBsU3CFTM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2633592AbfJRLsf (ORCPT ); Fri, 18 Oct 2019 07:48:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:58434 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729946AbfJRLse (ORCPT ); Fri, 18 Oct 2019 07:48:34 -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 3F776B537; Fri, 18 Oct 2019 11:48:33 +0000 (UTC) Date: Fri, 18 Oct 2019 13:48:32 +0200 From: Michal Hocko To: Oscar Salvador Cc: n-horiguchi@ah.jp.nec.com, mike.kravetz@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 01/16] mm,hwpoison: cleanup unused PageHuge() check Message-ID: <20191018114832.GK5017@dhcp22.suse.cz> References: <20191017142123.24245-1-osalvador@suse.de> <20191017142123.24245-2-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191017142123.24245-2-osalvador@suse.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 17-10-19 16:21:08, Oscar Salvador wrote: > From: Naoya Horiguchi > > Drop the PageHuge check since memory_failure forks into memory_failure_hugetlb() > for hugetlb pages. > > Signed-off-by: Oscar Salvador > Signed-off-by: Naoya Horiguchi s-o-b chain is reversed. The code is a bit confusing. Doesn't this check aim for THP? AFAICS PageTransHuge(hpage) will split the THP or fail so PageTransHuge shouldn't be possible anymore, right? But why does hwpoison_user_mappings still work with hpage then? > --- > mm/memory-failure.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 05c8c6df25e6..2cbadb58c7df 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1345,10 +1345,7 @@ int memory_failure(unsigned long pfn, int flags) > * page_remove_rmap() in try_to_unmap_one(). So to determine page status > * correctly, we save a copy of the page flags at this time. > */ > - if (PageHuge(p)) > - page_flags = hpage->flags; > - else > - page_flags = p->flags; > + page_flags = p->flags; > > /* > * unpoison always clear PG_hwpoison inside page lock > -- > 2.12.3 -- Michal Hocko SUSE Labs