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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D024CC433F5 for ; Sun, 30 Jan 2022 20:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356335AbiA3U6W (ORCPT ); Sun, 30 Jan 2022 15:58:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347702AbiA3U6T (ORCPT ); Sun, 30 Jan 2022 15:58:19 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2E3CC061714 for ; Sun, 30 Jan 2022 12:58:18 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id q63so11842369pja.1 for ; Sun, 30 Jan 2022 12:58:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:in-reply-to:message-id:references :mime-version; bh=0Y2zJfEVi4pNu6D2VEzI1me9RN7QGeq2qjfX5SiFYYQ=; b=m6oBcQNk1Bo/QB4mFD5fF6CwPoQrnqAefkgg9zkInR37Pvr3p45/yRg1/WXWLxn4nJ Z7x+Qo16PS3Ra5661QKLv3f1eLNklKFXli4ArNRVXVKqe4N3qpoNdjw7sbfuJLa3R72K EU59mMGMhmnjaJVa86yiheKs3ro+EAgKTjkOszGGMHf+UKGOdlErUeKhtddEignp1bnG DfX3LS9zKKhSS2dH1P0DkMS8o6IF4g2ve3LYMP6xVMkto/SLWRno9DvrxQvv1w6peKHm PRhUZRP8rhh1a6I3vyDEF9GAgQPBm0EHjNwVQsbux4E394VYICW2MpG2+rQ4pHoqzUhR +RJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version; bh=0Y2zJfEVi4pNu6D2VEzI1me9RN7QGeq2qjfX5SiFYYQ=; b=N7z0R65SDvZb7ndFtdIl30hIiMpC0sBS0TdjNkf8cymw1HN6Z8BbUWDrRvZwCMThGw YDxF4t9ljod4wLqWENA5WnEfdk3kQOiMAEvPBJzHpT8p5ADnZ4yI/m0MAd9BeMbid9Hz RXE6J0Rwzdhbzeut6CIi5B30rTYs0Afx1GBBNwvJnQ/651ie0bMqGGrPR4+PZXOLw5ex pUWBX/arNtZU8yjnk6CYmD7CoCnGvO/M+39MfKdfypGHrFd1qvurOQlYfFuLYV0tdGCy u/4+1333/5OXYiBnnlg3ko1JlmQlNL1ms4jLOv+ac1WwIYjgQbX5p4Qe3/1aqL12xFGI OAaA== X-Gm-Message-State: AOAM532Lo3+Bx+j34eXyAHn4/of5ZjTjAmA5BDM9Xsf2PDSNPl/BxehQ cLaj7LbW8MNFRejEFYumCCHhew== X-Google-Smtp-Source: ABdhPJwQIi+kXbC7Wc3kLdz4gg130hIgjG9shotxm9tSWZLMlb9nsGhkbRWCi9da3/tGRxE7v2u22w== X-Received: by 2002:a17:90b:2516:: with SMTP id ns22mr21188100pjb.242.1643576298007; Sun, 30 Jan 2022 12:58:18 -0800 (PST) Received: from [2620:15c:29:204:2b97:ce13:593d:973d] ([2620:15c:29:204:2b97:ce13:593d:973d]) by smtp.gmail.com with ESMTPSA id l13sm26870001pgs.16.2022.01.30.12.58.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 Jan 2022 12:58:17 -0800 (PST) Date: Sun, 30 Jan 2022 12:58:17 -0800 (PST) From: David Rientjes To: "Matthew Wilcox (Oracle)" cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi Subject: Re: [PATCH] mm/hwpoison: Check the subpage, not the head page In-Reply-To: <20220130013042.1906881-1-willy@infradead.org> Message-ID: References: <20220130013042.1906881-1-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 30 Jan 2022, Matthew Wilcox (Oracle) wrote: > Hardware poison is tracked on a per-page basis, not on the head page. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > mm/rmap.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 6a1e8c7f6213..09b08888120e 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1553,7 +1553,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, > /* Update high watermark before we lower rss */ > update_hiwater_rss(mm); > > - if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) { > + if (PageHWPoison(subpage) && !(flags & TTU_IGNORE_HWPOISON)) { > pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); > if (PageHuge(page)) { > hugetlb_count_sub(compound_nr(page), mm); > @@ -1873,7 +1873,7 @@ static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma, > * memory are supported. > */ > subpage = page; > - } else if (PageHWPoison(page)) { > + } else if (PageHWPoison(subpage)) { > pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); > if (PageHuge(page)) { > hugetlb_count_sub(compound_nr(page), mm); This looks correct. Correct me if I'm wrong that this is for consistency and cleanup and that there is no bug being fixed by this, however. Thanks!