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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E06AEC433F5 for ; Sat, 16 Apr 2022 01:06:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5CA4F6B0072; Fri, 15 Apr 2022 21:06:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 579136B0073; Fri, 15 Apr 2022 21:06:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 41ABB6B0074; Fri, 15 Apr 2022 21:06:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0069.hostedemail.com [216.40.44.69]) by kanga.kvack.org (Postfix) with ESMTP id 2F49A6B0072 for ; Fri, 15 Apr 2022 21:06:10 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id CCFD78249980 for ; Sat, 16 Apr 2022 01:06:09 +0000 (UTC) X-FDA: 79360950858.29.B2007B2 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf22.hostedemail.com (Postfix) with ESMTP id B6712C0007 for ; Sat, 16 Apr 2022 01:06:08 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KgFPl2pQPzgYdp; Sat, 16 Apr 2022 09:06:03 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 16 Apr 2022 09:06:04 +0800 Subject: Re: [PATCH 4/3] mm, hugetlb, hwpoison: separate branch for free and in-use hugepage To: Naoya Horiguchi , Mike Kravetz , Andrew Morton CC: Yang Shi , Dan Carpenter , , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" References: <20220408135323.1559401-1-naoya.horiguchi@linux.dev> <20220408135323.1559401-2-naoya.horiguchi@linux.dev> <5b665bcd-57f8-85ae-b0c4-c055875dbfff@oracle.com> <20e677e5-01aa-f8c0-0ce1-bf33da58b7ec@huawei.com> <20220415021233.GA3357039@hori.linux.bs1.fc.nec.co.jp> <20220415041848.GA3034499@ik1-406-35019.vs.sakura.ne.jp> From: Miaohe Lin Message-ID: Date: Sat, 16 Apr 2022 09:06:04 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220415041848.GA3034499@ik1-406-35019.vs.sakura.ne.jp> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Authentication-Results: imf22.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf22.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: B6712C0007 X-Stat-Signature: dtygqt4hq6oozm9pkr45u8zrrzf3zrru X-HE-Tag: 1650071168-733676 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 2022/4/15 12:18, Naoya Horiguchi wrote: > From: Naoya Horiguchi > > We know that HPageFreed pages should have page refcount 0, so > get_page_unless_zero() always fails and returns 0. So explicitly separate > the branch based on page state for minor optimization and better readability. > > Suggested-by: Mike Kravetz > Suggested-by: Miaohe Lin > Signed-off-by: Naoya Horiguchi > --- > mm/hugetlb.c | 4 +++- > mm/memory-failure.c | 4 +++- > 2 files changed, 6 insertions(+), 2 deletions(-) > Thanks! Reviewed-by: Miaohe Lin > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index e38cbfdf3e61..3638f166e554 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -6786,7 +6786,9 @@ int get_hwpoison_huge_page(struct page *page, bool *hugetlb) > spin_lock_irq(&hugetlb_lock); > if (PageHeadHuge(page)) { > *hugetlb = true; > - if (HPageFreed(page) || HPageMigratable(page)) > + if (HPageFreed(page)) > + ret = 0; > + else if (HPageMigratable(page)) > ret = get_page_unless_zero(page); > else > ret = -EBUSY; > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 5e3ad640f5bb..661079a37f29 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1517,7 +1517,9 @@ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) > if (flags & MF_COUNT_INCREASED) { > ret = 1; > count_increased = true; > - } else if (HPageFreed(head) || HPageMigratable(head)) { > + } else if (HPageFreed(head)) { > + ret = 0; > + } else if (HPageMigratable(head)) { > ret = get_page_unless_zero(head); > if (ret) > count_increased = true; >