From patchwork Wed Feb 16 09:14:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12748272 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 B7D22C4332F for ; Wed, 16 Feb 2022 09:15:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C8BEF6B007E; Wed, 16 Feb 2022 04:15:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A399A6B0080; Wed, 16 Feb 2022 04:15:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 754E36B0081; Wed, 16 Feb 2022 04:15:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 61AB96B0080 for ; Wed, 16 Feb 2022 04:15:19 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 07DF58249980 for ; Wed, 16 Feb 2022 09:15:19 +0000 (UTC) X-FDA: 79148084358.22.953EE78 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf25.hostedemail.com (Postfix) with ESMTP id 6FE3AA0004 for ; Wed, 16 Feb 2022 09:15:18 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4JzC2966Frzcd1q; Wed, 16 Feb 2022 17:14:09 +0800 (CST) Received: from huawei.com (10.175.124.27) 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 15.1.2308.21; Wed, 16 Feb 2022 17:15:15 +0800 From: Miaohe Lin To: , CC: , , Subject: [PATCH v2 6/8] mm/memory-failure.c: rework the try_to_unmap logic in hwpoison_user_mappings() Date: Wed, 16 Feb 2022 17:14:29 +0800 Message-ID: <20220216091431.39406-7-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220216091431.39406-1-linmiaohe@huawei.com> References: <20220216091431.39406-1-linmiaohe@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Stat-Signature: 1sfiumsusx3huphotiz1dhuxe1j69iis X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 6FE3AA0004 Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf25.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspam-User: X-HE-Tag: 1645002918-587062 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: Only for hugetlb pages in shared mappings, try_to_unmap should take semaphore in write mode here. Rework the code to make it clear. Signed-off-by: Miaohe Lin Acked-by: Naoya Horiguchi --- mm/memory-failure.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 791d89e0c15a..0100d4f9da9a 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1404,26 +1404,22 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, if (kill) collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED); - if (!PageHuge(hpage)) { - try_to_unmap(hpage, ttu); + if (PageHuge(hpage) && !PageAnon(hpage)) { + /* + * For hugetlb pages in shared mappings, try_to_unmap + * could potentially call huge_pmd_unshare. Because of + * this, take semaphore in write mode here and set + * TTU_RMAP_LOCKED to indicate we have taken the lock + * at this higher level. + */ + mapping = hugetlb_page_mapping_lock_write(hpage); + if (mapping) { + try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED); + i_mmap_unlock_write(mapping); + } else + pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn); } else { - if (!PageAnon(hpage)) { - /* - * For hugetlb pages in shared mappings, try_to_unmap - * could potentially call huge_pmd_unshare. Because of - * this, take semaphore in write mode here and set - * TTU_RMAP_LOCKED to indicate we have taken the lock - * at this higher level. - */ - mapping = hugetlb_page_mapping_lock_write(hpage); - if (mapping) { - try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED); - i_mmap_unlock_write(mapping); - } else - pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn); - } else { - try_to_unmap(hpage, ttu); - } + try_to_unmap(hpage, ttu); } unmap_success = !page_mapped(hpage);