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 7B3BDC19F2D for ; Fri, 5 Aug 2022 01:33:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A7BD18E0002; Thu, 4 Aug 2022 21:33:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A29748E0001; Thu, 4 Aug 2022 21:33:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8F1668E0002; Thu, 4 Aug 2022 21:33:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7C9C78E0001 for ; Thu, 4 Aug 2022 21:33:23 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 4B35112045A for ; Fri, 5 Aug 2022 01:33:23 +0000 (UTC) X-FDA: 79763816286.17.1AA1B24 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf11.hostedemail.com (Postfix) with ESMTP id 108644000F for ; Fri, 5 Aug 2022 01:33:21 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LzShm4XQHzlVn7; Fri, 5 Aug 2022 09:30:32 +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; Fri, 5 Aug 2022 09:33:17 +0800 Subject: Re: [PATCH] mm/memory-failure: release private data before split THP To: Yang Shi CC: , , , , , , Yin Fengwei References: <20220804025121.4001361-1-fengwei.yin@intel.com> From: Miaohe Lin Message-ID: <6a5629ce-f66f-96be-5c90-525eda5d5e92@huawei.com> Date: Fri, 5 Aug 2022 09:33:17 +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: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659663203; a=rsa-sha256; cv=none; b=sg90py+974sQfbD8FsatmSFNtr0UOVc9oOVUh843aFOD15+r61iE+AyQgeQHLaMfVfqeYu Sb1OK0RIfBkVAcCZkbrl9yghpUdJ2hEnvI7oyiXd8f5OutWIc23PEUaLvip3tpyZ1wt9qE mNfCeuSLEzCAbuOX01jixKuLi1vDcC8= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659663203; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lN7LGbJJdAxFGUt79URofn/G06OQmffiBFfLOYWA/1E=; b=O+2fjX+7EhMuDuxQfHE1pnNalJv/rdkpohzqhbXCn0a5cs1iea6vaSl3htGVfJrXduPvml W4Vce69KM+lCgVjvjQa9tOaW9u1PcmF6BqP8IPUqLjfo02mex0v20yHM+jIjhkq/9X7INH 9XmCbPYq3zJ3XSvFkmYBpBuumvYmrq8= X-Stat-Signature: hbiupw7jxpscntkyw8ttwy3abzbi941c X-Rspamd-Queue-Id: 108644000F Authentication-Results: imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspam-User: X-Rspamd-Server: rspam11 X-HE-Tag: 1659663201-900950 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 2022/8/5 1:39, Yang Shi wrote: > On Wed, Aug 3, 2022 at 7:52 PM Yin Fengwei wrote: >> >> If there is private data attached to THP, the refcount of >> THP will be increased and block the THP split. Which could >> further cause the meomry failure not recovered. >> >> Release private data attached to THP before split it to >> increase the chance of splitting THP successfully. >> >> The issue was hit during HW error injection testing with >> 5.18 kernel + xfs as rootfs, test got killed and system >> reboot was required to re-run the test. >> >> The issue was tracked down to THP split failure caused the >> memory failure not being handled. The page dump showed: >> >> [ 1785.433075] page:0000000025f9530b refcount:18 mapcount:0 mapping:000000008162eea7 index:0xa10 pfn:0x2f0200 >> [ 1785.443954] head:0000000025f9530b order:4 compound_mapcount:0 compound_pincount:0 >> [ 1785.452408] memcg:ff4247f2d28e9000 >> [ 1785.456304] aops:xfs_address_space_operations ino:8555182 dentry name:"baseos-filenames.solvx" >> [ 1785.466612] flags: 0x1000000000012036(referenced|uptodate|lru|active|private|head|node=0|zone=2) >> [ 1785.476514] raw: 1000000000012036 ffb9460f8bc07c08 ffb9460f8bc08408 ff4247f22e6299f8 >> [ 1785.485268] raw: 0000000000000a10 ff4247f194ade900 00000012ffffffff ff4247f2d28e9000 >> >> It was like the error was injected to a large folio for xfs with >> private data attached. >> >> With private data released before split THP, the test case >> could be run successfully many times without reboot system. > > Yes, now we have more file large pages/THP than before. The patch > itself looks good to me. But I'm wondering whether it is better to > release buffer in split_huge_page() itself since other callsites may > experience the same issue. Before only anonymous and shmem THP were > supported so we don't have to worry about the extra pin from buffers, > but it may be time to consider it now. I tend to agree with this idea. Thank Yang. > >> >> Co-developed-by: Qiuxu Zhuo >> Signed-off-by: Qiuxu Zhuo >> Signed-off-by: Yin Fengwei >> Suggested-by: Matthew Wilcox >> Reviewed-by: Aaron Lu >> --- >> Changelog from RFC: >> - Use new folio API per Mathhew Wilcox's suggestion >> - Add one line comment before re-get folio of page per >> Miaohe's comment >> - Remove RFC tag >> - Add Co-developed-by of Qiuxu who did a lot of debugging >> work to locate where the real issue is >> >> mm/memory-failure.c | 16 ++++++++++++---- >> 1 file changed, 12 insertions(+), 4 deletions(-) >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index b864c2eff641..ef87741b0fea 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -1484,16 +1484,24 @@ static int identify_page_state(unsigned long pfn, struct page *p, >> >> static int try_to_split_thp_page(struct page *page, const char *msg) >> { >> - lock_page(page); >> + struct folio *folio = page_folio(page); >> + >> + folio_lock(folio); >> + if (folio_test_private(folio)) >> + filemap_release_folio(folio, GFP_KERNEL); >> + >> if (unlikely(split_huge_page(page))) { >> unsigned long pfn = page_to_pfn(page); >> >> - unlock_page(page); >> + folio_unlock(folio); >> pr_info("%s: %#lx: thp split failed\n", msg, pfn); >> - put_page(page); >> + folio_put(folio); >> return -EBUSY; >> } >> - unlock_page(page); >> + >> + /* If split_huge_page success, folio could be different */ >> + folio = page_folio(page); >> + folio_unlock(folio); >> >> return 0; >> } >> >> base-commit: f86d1fbbe7858884d6754534a0afbb74fc30bc26 >> -- >> 2.25.1 >> >> > . >