From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3031306-1521206088-2-14490086498800801458 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES rosk.us-asciien, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='jp', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1521206087; b=NXp/BMTZdZi/evvUprSuHPwifnH7w67jId3l1Lq6D/vUwhl kIIEwu7AeMi0RPMhlXZt7xNRPcNNQsStiGkhwLdJ/2kJXm3blfzG+Hvz+Ov5wEL2 eKT0qu/Llo/OyA5gzWtCWQVRNlhXmlVAlvNlME4s109c+XA0kcCO2BxIm+gqMrKL L/oWvPab9Bd8+UTSRAlAqsjSfmyVT/Vb80CH/4OotD7ABZYiO/X1YICv1h/ZqmPx XaW6NAdUG/s04uFDVritkH23cUj+UGNOTI6oHd0F23wBXYbLWK3Joz8KmlDmgFqp H3/sK5C7l1Wrpp38/nW+8Qeq5nb1qW552HYeiZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=to:cc:subject:from:references:in-reply-to :message-id:date:mime-version:content-type:sender:list-id; s= arctest; t=1521206087; bh=37QKzKpBOnUqFRqAcY2+THeYAff+SzFo2MAO+d 0CYd4=; b=cx9CmrWZPoN4PFjZpUjP8Py+3s5Nmza64twdxg5YHxWc1CGsxxy1hf RFvONjUefCA02rEROdsfMAvcF4QY/Rg8QH0Q0M1E1kNbDqWyD7pwu9ikxxU2F6g9 rlTvZF9mg0YsqjzkjLuP95xjmbhb02e8Uqrj/5l0C5ZiSVnx8Er/Qyh4+jVDRGqt yhaCQioStQCbGE3JDsrcCrasbNozsBIiG71UGG67OY0lvTUtGX16Aehc//eE7vY6 k/PccyaglX3nlBzNft0h7m95A0vfZbblFR8IR3V+NOcwkJJ+ceL5bvtvbwaFbmcF d76iDuKk76/qbYW6EbCyO7xczSJTf+yQ== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=i-love.sakura.ne.jp; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=0 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=i-love.sakura.ne.jp header.result=pass header_org.domain=sakura.ne.jp header_org.result=pass header_is_org_domain=no Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=i-love.sakura.ne.jp; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=0 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=i-love.sakura.ne.jp header.result=pass header_org.domain=sakura.ne.jp header_org.result=pass header_is_org_domain=no Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752206AbeCPNOr (ORCPT ); Fri, 16 Mar 2018 09:14:47 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:15750 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751871AbeCPNOq (ORCPT ); Fri, 16 Mar 2018 09:14:46 -0400 To: kirill@shutemov.name, mhocko@kernel.org Cc: kirill.shutemov@linux.intel.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mm@lists.ewheeler.net Subject: Re: [PATCH] mm/shmem: Do not wait for lock_page() in shmem_unused_huge_shrink() From: Tetsuo Handa References: <20180316105908.62516-1-kirill.shutemov@linux.intel.com> <20180316121303.GI23100@dhcp22.suse.cz> <20180316122508.fv4edpx34hdqybwx@node.shutemov.name> <20180316125827.GC11461@dhcp22.suse.cz> <20180316130200.rbke66zjyoc6zwzl@node.shutemov.name> In-Reply-To: <20180316130200.rbke66zjyoc6zwzl@node.shutemov.name> Message-Id: <201803162214.ECJ30715.StOOFHOFVLJMQF@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.51 PL2] X-Accept-Language: ja,en,zh Date: Fri, 16 Mar 2018 22:14:24 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: f2fs is doing page = f2fs_pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0); which calls struct page *pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0); . Then, can't we define static inline struct page *find_trylock_page(struct address_space *mapping, pgoff_t offset) { return pagecache_get_page(mapping, offset, FGP_LOCK|FGP_NOWAIT, 0); } and replace find_lock_page() with find_trylock_page() ? Also, won't ---------- diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 34ce3ebf..0cfc329 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -479,6 +479,8 @@ static inline int trylock_page(struct page *page) static inline void lock_page(struct page *page) { might_sleep(); + WARN_ONCE(current->flags & PF_MEMALLOC, + "lock_page() from reclaim context might deadlock"); if (!trylock_page(page)) __lock_page(page); } @@ -491,6 +493,8 @@ static inline void lock_page(struct page *page) static inline int lock_page_killable(struct page *page) { might_sleep(); + WARN_ONCE(current->flags & PF_MEMALLOC, + "lock_page_killable() from reclaim context might deadlock"); if (!trylock_page(page)) return __lock_page_killable(page); return 0; ---------- help find lock_page() users in deep reclaim paths? ---------- [ 100.314083] ------------[ cut here ]------------ [ 100.315695] lock_page() from reclaim context might deadlock [ 100.315708] WARNING: CPU: 1 PID: 56 at ./include/linux/pagemap.h:483 pagecache_get_page+0x245/0x250 [ 100.319686] Modules linked in: sg pcspkr i2c_piix4 vmw_vmci shpchp sd_mod ata_generic pata_acpi serio_raw vmwgfx drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ahci mptspi libahci scsi_transport_spi mptscsih ata_piix mptbase i2c_core e1000 libata ipv6 [ 100.325951] CPU: 1 PID: 56 Comm: kswapd0 Kdump: loaded Not tainted 4.16.0-rc5-next-20180315+ #696 [ 100.328439] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [ 100.331625] RIP: 0010:pagecache_get_page+0x245/0x250 [ 100.333211] RSP: 0018:ffffc9000085bc00 EFLAGS: 00010286 [ 100.334832] RAX: 0000000000000000 RBX: ffffea0004ad3100 RCX: 0000000000000007 [ 100.336900] RDX: 0000000000000b63 RSI: ffff88013aa0b700 RDI: ffff88013aa0ae80 [ 100.339068] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 100.341108] R10: 0000000000000040 R11: 0000000000000000 R12: ffff880139b6e0c8 [ 100.343153] R13: 0000000000000000 R14: ffffffff82068220 R15: 0000000000000002 [ 100.345242] FS: 0000000000000000(0000) GS:ffff88013bc40000(0000) knlGS:0000000000000000 [ 100.347510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 100.349277] CR2: 00007f326c67e000 CR3: 000000000200f006 CR4: 00000000001606e0 [ 100.351343] Call Trace: [ 100.352374] ? iput+0x52/0x2f0 [ 100.353567] shmem_unused_huge_shrink+0x2e9/0x380 [ 100.355112] super_cache_scan+0x17a/0x180 [ 100.356553] shrink_slab+0x218/0x590 [ 100.357854] shrink_node+0x346/0x350 [ 100.359161] kswapd+0x322/0x930 [ 100.360370] kthread+0xf0/0x130 [ 100.361566] ? mem_cgroup_shrink_node+0x320/0x320 [ 100.363112] ? kthread_create_on_node+0x60/0x60 [ 100.364634] ret_from_fork+0x3a/0x50 [ 100.365943] Code: db e8 70 4c 01 00 e9 5e fe ff ff 80 3d 44 51 f8 00 00 0f 85 46 ff ff ff 48 c7 c7 60 11 df 81 c6 05 30 51 f8 00 01 e8 5b 86 ee ff <0f> 0b e9 2c ff ff ff 0f 1f 40 00 83 e2 02 53 8b 8f 48 01 00 00 [ 100.371197] ---[ end trace b50eee6f891efec3 ]--- ----------