From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 910CE6B0038 for ; Mon, 23 Jan 2017 16:51:13 -0500 (EST) Received: by mail-pg0-f70.google.com with SMTP id 14so213874377pgg.4 for ; Mon, 23 Jan 2017 13:51:13 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id c1si16849347pld.50.2017.01.23.13.51.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 Jan 2017 13:51:12 -0800 (PST) Date: Mon, 23 Jan 2017 13:51:11 -0800 From: Andrew Morton Subject: Re: [Bug 192981] New: page allocation stalls Message-Id: <20170123135111.13ac3e47110de10a4bd503ef@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: bugzilla-daemon@bugzilla.kernel.org, apolyakov@beget.ru (switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). A 2100 second page allocation stall! On Fri, 20 Jan 2017 15:14:13 +0000 bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=192981 > > Bug ID: 192981 > Summary: page allocation stalls > Product: Memory Management > Version: 2.5 > Kernel Version: 4.9 > Hardware: x86-64 > OS: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Page Allocator > Assignee: akpm@linux-foundation.org > Reporter: apolyakov@beget.ru > Regression: No > > Created attachment 252621 > --> https://bugzilla.kernel.org/attachment.cgi?id=252621&action=edit > netconsole log with page allocation stalls > > We have been experiencing page allocation stalls regularly on our machines used > as backup servers (many disks, mostly running rsync and rm). > > A notable one (2102516ms): > > 2017-01-17T11:08:33.754562+03:00 storage8 [335170.452601] rsync: > 2017-01-17T11:08:33.754574+03:00 page allocation stalls for 2102516ms, order:0 > 2017-01-17T11:08:33.754825+03:00 storage8 , > mode:0x26040d0(GFP_TEMPORARY|__GFP_COMP|__GFP_NOTRACK) > 2017-01-17T11:08:33.755094+03:00 storage8 [335170.452896] CPU: 2 PID: 20383 > Comm: rsync Tainted: G O 4.9.0-0-beget-vanilla #1 > 2017-01-17T11:08:33.755337+03:00 storage8 [335170.453156] Hardware name: > Supermicro X8DTL/X8DTL, BIOS 2.1b 11/16/2012 > 2017-01-17T11:08:33.755379+03:00 storage8 [335170.453414] 0000000000000000 > 2017-01-17T11:08:33.755379+03:00 storage8 ffffffff92441e0b > 2017-01-17T11:08:33.755393+03:00 storage8 ffff8c4b0f30f430 > 2017-01-17T11:08:33.755484+03:00 storage8 0000000000000001 > 2017-01-17T11:08:33.755600+03:00 storage8 > 2017-01-17T11:08:33.755603+03:00 storage8 [335170.453681] ffffffff92c3d1f8 > 2017-01-17T11:08:33.755643+03:00 storage8 ffffffff92189594 > 2017-01-17T11:08:33.755648+03:00 storage8 ffff8c4b0f315088 > 2017-01-17T11:08:33.755754+03:00 storage8 026040d0026040d0 > 2017-01-17T11:08:33.755874+03:00 storage8 > 2017-01-17T11:08:33.755874+03:00 storage8 [335170.453951] 0000000000000020 > 2017-01-17T11:08:33.755880+03:00 storage8 0000000000000010 > 2017-01-17T11:08:33.755913+03:00 storage8 ffffa449d15cb7f8 > 2017-01-17T11:08:33.756024+03:00 storage8 ffffa449d15cb7a8 > 2017-01-17T11:08:33.756163+03:00 storage8 > 2017-01-17T11:08:33.756278+03:00 storage8 [335170.454216] Call Trace: > 2017-01-17T11:08:33.756401+03:00 storage8 [335170.454347] [] > ? dump_stack+0x47/0x5c > 2017-01-17T11:08:33.756537+03:00 storage8 [335170.454479] [] > ? warn_alloc+0x134/0x150 > 2017-01-17T11:08:33.756677+03:00 storage8 [335170.454612] [] > ? __alloc_pages_nodemask+0x90d/0xdb0 > 2017-01-17T11:08:33.756808+03:00 storage8 [335170.454753] [] > ? _xfs_trans_bjoin+0xe4/0x110 > 2017-01-17T11:08:33.756955+03:00 storage8 [335170.454892] [] > ? alloc_pages_current+0x9a/0x120 > 2017-01-17T11:08:33.757096+03:00 storage8 [335170.455027] [] > ? new_slab+0x550/0x5f0 > 2017-01-17T11:08:33.757218+03:00 storage8 [335170.455162] [] > ? ___slab_alloc.isra.59+0x3db/0x500 > 2017-01-17T11:08:33.757346+03:00 storage8 [335170.455297] [] > ? xfs_trans_brelse+0x1aa/0x270 > 2017-01-17T11:08:33.757489+03:00 storage8 [335170.455427] [] > ? memcg_kmem_get_cache+0x72/0x170 > 2017-01-17T11:08:33.757632+03:00 storage8 [335170.455567] [] > ? __radix_tree_create+0xa7/0x320 > 2017-01-17T11:08:33.757762+03:00 storage8 [335170.455706] [] > ? __slab_alloc.isra.60+0xe/0x12 > 2017-01-17T11:08:33.757897+03:00 storage8 [335170.455842] [] > ? kmem_cache_alloc+0x1a0/0x1b0 > 2017-01-17T11:08:33.758034+03:00 storage8 [335170.455978] [] > ? __d_alloc+0x26/0x1c0 > 2017-01-17T11:08:33.758160+03:00 storage8 [335170.456108] [] > ? d_alloc+0x17/0x80 > 2017-01-17T11:08:33.758290+03:00 storage8 [335170.456236] [] > ? d_alloc_parallel+0x31/0x4b0 > 2017-01-17T11:08:33.758429+03:00 storage8 [335170.456370] [] > ? lookup_fast+0x56/0x2f0 > 2017-01-17T11:08:33.758579+03:00 storage8 [335170.456505] [] > ? xfs_iunlock+0x17e/0x210 > 2017-01-17T11:08:33.758694+03:00 storage8 [335170.456635] [] > ? legitimize_mnt+0x12/0x40 > 2017-01-17T11:08:33.758818+03:00 storage8 [335170.456770] [] > ? lookup_slow+0x80/0x170 > 2017-01-17T11:08:33.758955+03:00 storage8 [335170.456897] [] > ? walk_component+0x1a8/0x270 > 2017-01-17T11:08:33.759086+03:00 storage8 [335170.457024] [] > ? path_lookupat+0x48/0xf0 > 2017-01-17T11:08:33.759200+03:00 storage8 [335170.457153] [] > ? filename_lookup+0xb5/0x190 > 2017-01-17T11:08:33.759336+03:00 storage8 [335170.457282] [] > ? strncpy_from_user+0x42/0x140 > 2017-01-17T11:08:33.759462+03:00 storage8 [335170.457411] [] > ? getname_flags+0x7b/0x200 > 2017-01-17T11:08:33.759593+03:00 storage8 [335170.457538] [] > ? vfs_fstatat+0x46/0x90 > 2017-01-17T11:08:33.759719+03:00 storage8 [335170.457666] [] > ? dput+0x34/0x200 > 2017-01-17T11:08:33.759859+03:00 storage8 [335170.457793] [] > ? SyS_newlstat+0x17/0x30 > 2017-01-17T11:08:33.759977+03:00 storage8 [335170.457923] [] > ? entry_SYSCALL_64_fastpath+0x13/0x94 > > > # sysctl vm > vm.admin_reserve_kbytes = 1048576 > vm.block_dump = 0 > error: permission denied on key 'vm.compact_memory' > vm.compact_unevictable_allowed = 1 > vm.dirty_background_bytes = 0 > vm.dirty_background_ratio = 1 > vm.dirty_bytes = 0 > vm.dirty_expire_centisecs = 1000 > vm.dirty_ratio = 1 > vm.dirty_writeback_centisecs = 100 > vm.dirtytime_expire_seconds = 43200 > vm.drop_caches = 0 > vm.extfrag_threshold = 500 > vm.hugepages_treat_as_movable = 0 > vm.hugetlb_shm_group = 0 > vm.laptop_mode = 0 > vm.legacy_va_layout = 0 > vm.lowmem_reserve_ratio = 128 128 16 > vm.max_map_count = 65530 > vm.memory_failure_early_kill = 0 > vm.memory_failure_recovery = 1 > vm.min_free_kbytes = 4194304 > vm.min_slab_ratio = 1 > vm.min_unmapped_ratio = 1 > vm.mmap_min_addr = 65536 > vm.mmap_rnd_bits = 28 > vm.nr_hugepages = 0 > vm.nr_hugepages_mempolicy = 0 > vm.nr_overcommit_hugepages = 0 > vm.nr_pdflush_threads = 0 > vm.numa_zonelist_order = default > vm.oom_dump_tasks = 1 > vm.oom_kill_allocating_task = 0 > vm.overcommit_kbytes = 0 > vm.overcommit_memory = 1 > vm.overcommit_ratio = 50 > vm.page-cluster = 3 > vm.panic_on_oom = 0 > vm.percpu_pagelist_fraction = 0 > vm.stat_interval = 1 > error: permission denied on key 'vm.stat_refresh' > vm.swappiness = 0 > vm.user_reserve_kbytes = 131072 > vm.vfs_cache_pressure = 200 > vm.watermark_scale_factor = 100 > vm.zone_reclaim_mode = 7 > > # free -m > total used free shared buffers cached > Mem: 96646 46330 50315 0 25529 1228 > -/+ buffers/cache: 19572 77073 > Swap: 0 0 0 > > (Yes, we don't have any swap configured) > > On this particular one we have 56 disks, using both XFS and EXT4. I attach full > netconsole log for 18/01/2017. You can see there that we run drop_caches > regularly as it helps to keep the machine alive. > > Since then we've also tried mounting filesystems with sync flag to avoid > writeback and it seems to have helped a lot (full day without stalls). > > -- > You are receiving this mail because: > You are the assignee for the bug. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org