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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 21E50C4338F for ; Tue, 27 Jul 2021 03:33:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ACC4F61077 for ; Tue, 27 Jul 2021 03:33:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org ACC4F61077 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=vivo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 245606B005D; Mon, 26 Jul 2021 23:33:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1F5AE8D0001; Mon, 26 Jul 2021 23:33:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 10B246B0070; Mon, 26 Jul 2021 23:33:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0245.hostedemail.com [216.40.44.245]) by kanga.kvack.org (Postfix) with ESMTP id EBE806B005D for ; Mon, 26 Jul 2021 23:33:44 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 9F3DD8249980 for ; Tue, 27 Jul 2021 03:33:44 +0000 (UTC) X-FDA: 78406948368.10.67B9E35 Received: from mail-m118208.qiye.163.com (mail-m118208.qiye.163.com [115.236.118.208]) by imf15.hostedemail.com (Postfix) with SMTP id 89CB0D0020F6 for ; Tue, 27 Jul 2021 03:33:43 +0000 (UTC) DKIM-Signature: a=rsa-sha256; b=ABBMxIWpIg9L/+HOKYm9N1K3nPL1ofAhoRb4Dm66I2pA+wli25VBZg/N0i6mDzrm9zPMT73QTa8Zq3dbUZO59+M9fg+NiqGeg4rKGcRl35JF41+7dWgONWXkly4teBrxqr6qWEvTVzKjC86vKOlDKoE+UDUONjzKgovIecZpwaw=; c=relaxed/relaxed; s=default; d=vivo.com; v=1; bh=fgFn2CfqfI5yLqGF+VB3uiM6py0rkY8NZLedV5hh+AU=; h=date:mime-version:subject:message-id:from; Received: from vivo-HP-ProDesk-680-G4-PCI-MT.vivo.xyz (unknown [58.251.74.232]) by mail-m118208.qiye.163.com (Hmail) with ESMTPA id 722B7E0121; Tue, 27 Jul 2021 11:33:30 +0800 (CST) From: Wang Qing To: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Wang Qing Subject: [PATCH] mm: folio: use copy_highpage() instead of folio_migrate_copy() when copy once Date: Tue, 27 Jul 2021 11:32:54 +0800 Message-Id: <1627356775-28742-1-git-send-email-wangqing@vivo.com> X-Mailer: git-send-email 2.7.4 X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgPGg8OCBgUHx5ZQUlOS1dZCBgUCR5ZQVlLVUtZV1 kWDxoPAgseWUFZKDYvK1lXWShZQUhPN1dZLVlBSVdZDwkaFQgSH1lBWRpPSUpWSx8dTR5NHkNNTE 9PVRMBExYaEhckFA4PWVdZFhoPEhUdFFlBWU9LSFVKSktISkxVS1kG X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6NU06SBw6Ez9NDEwtFEk9LU0c NDYaCzxVSlVKTUlMSE5NQ0pKS0lDVTMWGhIXVQwaFRwKEhUcOw0SDRRVGBQWRVlXWRILWUFZTkNV SU5KVUxPVUlISVlXWQgBWUFITkxMNwY+ X-HM-Tid: 0a7ae6064d672c17kusn722b7e0121 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 89CB0D0020F6 Authentication-Results: imf15.hostedemail.com; dkim=none ("invalid DKIM record") header.d=vivo.com header.s=default header.b=ABBMxIWp; dmarc=pass (policy=none) header.from=vivo.com; spf=pass (imf15.hostedemail.com: domain of wangqing@vivo.com designates 115.236.118.208 as permitted sender) smtp.mailfrom=wangqing@vivo.com X-Stat-Signature: wrao8tuswc3ux9q5jzueuu3zrxkzud44 X-HE-Tag: 1627356823-652141 X-Bogosity: Ham, tests=bogofilter, spamicity=0.011847, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: folio_migrate_copy() will call cond_resched(), even if it only needs to be copied once, restore the previous implementation before there is a better solution: use copy_highpage() when copy once. Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 ___might_sleep.cold+0x1f3/0x239 kernel/sched/core.c:9182 folio_copy+0x10c/0x1a0 mm/util.c:761 folio_migrate_copy+0x19/0x30 mm/migrate.c:619 __buffer_migrate_page+0x820/0xa80 mm/migrate.c:757 move_to_new_page+0x339/0xf00 mm/migrate.c:904 __unmap_and_move mm/migrate.c:1069 [inline] unmap_and_move mm/migrate.c:1210 [inline] migrate_pages+0x2867/0x3890 mm/migrate.c:1487 compact_zone+0x1abb/0x3860 mm/compaction.c:2393 kcompactd_do_work+0x2c9/0x730 mm/compaction.c:2808 kcompactd+0x262/0xd10 mm/compaction.c:2903 kthread+0x3e5/0x4d0 kernel/kthread.c:319 Reported-by: syzbot+bb4c69145b4a52b40b27@syzkaller.appspotmail.com Signed-off-by: Wang Qing --- mm/folio-compat.c | 6 ------ mm/migrate.c | 15 +++++++++++---- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 5b6ae1d..13ec6aa --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -64,12 +64,6 @@ void migrate_page_states(struct page *newpage, struct page *page) folio_migrate_flags(page_folio(newpage), page_folio(page)); } EXPORT_SYMBOL(migrate_page_states); - -void migrate_page_copy(struct page *newpage, struct page *page) -{ - folio_migrate_copy(page_folio(newpage), page_folio(page)); -} -EXPORT_SYMBOL(migrate_page_copy); #endif bool set_page_writeback(struct page *page) diff --git a/mm/migrate.c b/mm/migrate.c index 7d06515..8fb796b --- a/mm/migrate.c +++ b/mm/migrate.c @@ -614,12 +614,19 @@ void folio_migrate_flags(struct folio *newfolio, struct folio *folio) } EXPORT_SYMBOL(folio_migrate_flags); -void folio_migrate_copy(struct folio *newfolio, struct folio *folio) +void migrate_page_copy(struct page *newpage, struct page *page) { - folio_copy(newfolio, folio); + struct folio *newfolio = page_folio(newpage); + struct folio *folio = page_folio(page); + + if (PageHuge(page) || PageTransHuge(page)) + folio_copy(newfolio, folio); + else + copy_highpage(newpage, page); + folio_migrate_flags(newfolio, folio); } -EXPORT_SYMBOL(folio_migrate_copy); +EXPORT_SYMBOL(migrate_page_copy); /************************************************************ * Migration functions @@ -647,7 +654,7 @@ int migrate_page(struct address_space *mapping, return rc; if (mode != MIGRATE_SYNC_NO_COPY) - folio_migrate_copy(newfolio, folio); + migrate_page_copy(newpage, page); else folio_migrate_flags(newfolio, folio); return MIGRATEPAGE_SUCCESS; -- 2.7.4