From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87D731448C0 for ; Fri, 26 Apr 2024 11:03:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714129442; cv=none; b=g5ouAg/Y9E5Lb0ouGscsrlo3OalJ4LIJG3ADSF/oAFi8G12+6GMKGLew6Af2muad+JMmDLwAcdfelzcZcapcffmHmvuo9tny1m8cZHi7/8OT8ZCu+TY12Yf9G/4GhFqspU4bwftxAga+QhoLdzTZLEPYw3U9WPZtXW87JHcKaBQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714129442; c=relaxed/simple; bh=tzR3XdCEfmS2ZkWPhvbHV8Jec/WfmOU0PJhTLTgblx4=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=fP/dbVVA9quKoSOtBANGVyY55FhWJP24K67JPY9OkLZPHpuwc7yeYAjnyUwEgUkbKOL8Ck725hrO300UQ1deC8/ILbAMI4RV0KVbJw9FSdgfQ1tvfuIHZOuZD2cGEjew1Zg52MOfSpPg22Fg2Smw9bAuEez3QXa3BQmespEFOcc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4VQqX150ZMzvPrN; Fri, 26 Apr 2024 19:00:49 +0800 (CST) Received: from dggpemm100001.china.huawei.com (unknown [7.185.36.93]) by mail.maildlp.com (Postfix) with ESMTPS id 085E418005C; Fri, 26 Apr 2024 19:03:54 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Fri, 26 Apr 2024 19:03:53 +0800 From: Kefeng Wang To: Andrew Morton CC: "Matthew Wilcox (Oracle)" , , , Kefeng Wang , zhangyi Subject: [PATCH] mm: use memalloc_nofs_save() in page_cache_ra_order() Date: Fri, 26 Apr 2024 19:29:38 +0800 Message-ID: <20240426112938.124740-1-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.41.0 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm100001.china.huawei.com (7.185.36.93) See commit f2c817bed58d ("mm: use memalloc_nofs_save in readahead path"), ensure that page_cache_ra_order() do not attempt to reclaim file-backed pages too, or it leads to a deadlock, found issue when test ext4 large folio. INFO: task DataXceiver for:7494 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:DataXceiver for state:D stack:0 pid:7494 ppid:1 flags:0x00000200 Call trace: __switch_to+0x14c/0x240 __schedule+0x82c/0xdd0 schedule+0x58/0xf0 io_schedule+0x24/0xa0 __folio_lock+0x130/0x300 migrate_pages_batch+0x378/0x918 migrate_pages+0x350/0x700 compact_zone+0x63c/0xb38 compact_zone_order+0xc0/0x118 try_to_compact_pages+0xb0/0x280 __alloc_pages_direct_compact+0x98/0x248 __alloc_pages+0x510/0x1110 alloc_pages+0x9c/0x130 folio_alloc+0x20/0x78 filemap_alloc_folio+0x8c/0x1b0 page_cache_ra_order+0x174/0x308 ondemand_readahead+0x1c8/0x2b8 page_cache_async_ra+0x68/0xb8 filemap_readahead.isra.0+0x64/0xa8 filemap_get_pages+0x3fc/0x5b0 filemap_splice_read+0xf4/0x280 ext4_file_splice_read+0x2c/0x48 [ext4] vfs_splice_read.part.0+0xa8/0x118 splice_direct_to_actor+0xbc/0x288 do_splice_direct+0x9c/0x108 do_sendfile+0x328/0x468 __arm64_sys_sendfile64+0x8c/0x148 invoke_syscall+0x4c/0x118 el0_svc_common.constprop.0+0xc8/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x4c/0x1f8 el0t_64_sync_handler+0xc0/0xc8 el0t_64_sync+0x188/0x190 Cc: zhangyi (F) Signed-off-by: Kefeng Wang --- mm/readahead.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/readahead.c b/mm/readahead.c index 63d6000103f0..c1b23989d9ca 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -494,6 +494,7 @@ void page_cache_ra_order(struct readahead_control *ractl, pgoff_t index = readahead_index(ractl); pgoff_t limit = (i_size_read(mapping->host) - 1) >> PAGE_SHIFT; pgoff_t mark = index + ra->size - ra->async_size; + unsigned int nofs; int err = 0; gfp_t gfp = readahead_gfp_mask(mapping); @@ -508,6 +509,8 @@ void page_cache_ra_order(struct readahead_control *ractl, new_order = min_t(unsigned int, new_order, ilog2(ra->size)); } + /* See comment in page_cache_ra_unbounded() */ + nofs = memalloc_nofs_save(); filemap_invalidate_lock_shared(mapping); while (index <= limit) { unsigned int order = new_order; @@ -531,6 +534,7 @@ void page_cache_ra_order(struct readahead_control *ractl, read_pages(ractl); filemap_invalidate_unlock_shared(mapping); + memalloc_nofs_restore(nofs); /* * If there were already pages in the page cache, then we may have -- 2.41.0