Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758418Ab1E0HUh (ORCPT ); Fri, 27 May 2011 03:20:37 -0400 Received: from smtp-out.google.com ([74.125.121.67]:37111 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525Ab1E0HUf convert rfc822-to-8bit (ORCPT ); Fri, 27 May 2011 03:20:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=YBqET68OJ4nLDV+O7o1ymoZAtTJzbSD1Yd9ON6J1b+m5T8iv+JLar4NImVuLW1uQTB dr6Yirlx7b7x7YB06QLA== MIME-Version: 1.0 In-Reply-To: References: <20110526141047.dc828124.kamezawa.hiroyu@jp.fujitsu.com> <20110527111639.22e3e257.kamezawa.hiroyu@jp.fujitsu.com> <20110527133431.471eefc2.kamezawa.hiroyu@jp.fujitsu.com> Date: Fri, 27 May 2011 00:20:18 -0700 Message-ID: Subject: Re: [RFC][PATCH v3 0/10] memcg async reclaim From: Ying Han To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11657 Lines: 311 On Thu, May 26, 2011 at 9:49 PM, Ying Han wrote: > On Thu, May 26, 2011 at 9:34 PM, KAMEZAWA Hiroyuki > wrote: >> On Thu, 26 May 2011 21:33:32 -0700 >> Ying Han wrote: >> >>> On Thu, May 26, 2011 at 7:16 PM, KAMEZAWA Hiroyuki >>> wrote: >>> > On Thu, 26 May 2011 18:49:26 -0700 >>> > Ying Han wrote: >>> > >>> >> On Wed, May 25, 2011 at 10:10 PM, KAMEZAWA Hiroyuki >>> >> wrote: >>> >> > >>> >> > It's now merge window...I just dump my patch queue to hear other's idea. >>> >> > I wonder I should wait until dirty_ratio for memcg is queued to mmotm... >>> >> > I'll be busy with LinuxCon Japan etc...in the next week. >>> >> > >>> >> > This patch is onto mmotm-May-11 + some patches queued in mmotm, as numa_stat. >>> >> > >>> >> > This is a patch for memcg to keep margin to the limit in background. >>> >> > By keeping some margin to the limit in background, application can >>> >> > avoid foreground memory reclaim at charge() and this will help latency. >>> >> > >>> >> > Main changes from v2 is. >>> >> > ?- use SCHED_IDLE. >>> >> > ?- removed most of heuristic codes. Now, code is very simple. >>> >> > >>> >> > By using SCHED_IDLE, async memory reclaim can only consume 0.3%? of cpu >>> >> > if the system is truely busy but can use much CPU if the cpu is idle. >>> >> > Because my purpose is for reducing latency without affecting other running >>> >> > applications, SCHED_IDLE fits this work. >>> >> > >>> >> > If application need to stop by some I/O or event, background memory reclaim >>> >> > will cull memory while the system is idle. >>> >> > >>> >> > Perforemce: >>> >> > ?Running an httpd (apache) under 300M limit. And access 600MB working set >>> >> > ?with normalized distribution access by apatch-bench. >>> >> > ?apatch bench's concurrency was 4 and did 40960 accesses. >>> >> > >>> >> > Without async reclaim: >>> >> > Connection Times (ms) >>> >> > ? ? ? ? ? ? ?min ?mean[+/-sd] median ? max >>> >> > Connect: ? ? ? ?0 ? ?0 ? 0.0 ? ? ?0 ? ? ? 2 >>> >> > Processing: ? ?30 ? 37 ?28.3 ? ? 32 ? ?1793 >>> >> > Waiting: ? ? ? 28 ? 35 ?25.5 ? ? 31 ? ?1792 >>> >> > Total: ? ? ? ? 30 ? 37 ?28.4 ? ? 32 ? ?1793 >>> >> > >>> >> > Percentage of the requests served within a certain time (ms) >>> >> > ?50% ? ? 32 >>> >> > ?66% ? ? 32 >>> >> > ?75% ? ? 33 >>> >> > ?80% ? ? 34 >>> >> > ?90% ? ? 39 >>> >> > ?95% ? ? 60 >>> >> > ?98% ? ?100 >>> >> > ?99% ? ?133 >>> >> > ?100% ? 1793 (longest request) >>> >> > >>> >> > With async reclaim: >>> >> > Connection Times (ms) >>> >> > ? ? ? ? ? ? ?min ?mean[+/-sd] median ? max >>> >> > Connect: ? ? ? ?0 ? ?0 ? 0.0 ? ? ?0 ? ? ? 2 >>> >> > Processing: ? ?30 ? 35 ?12.3 ? ? 32 ? ? 678 >>> >> > Waiting: ? ? ? 28 ? 34 ?12.0 ? ? 31 ? ? 658 >>> >> > Total: ? ? ? ? 30 ? 35 ?12.3 ? ? 32 ? ? 678 >>> >> > >>> >> > Percentage of the requests served within a certain time (ms) >>> >> > ?50% ? ? 32 >>> >> > ?66% ? ? 32 >>> >> > ?75% ? ? 33 >>> >> > ?80% ? ? 34 >>> >> > ?90% ? ? 39 >>> >> > ?95% ? ? 49 >>> >> > ?98% ? ? 71 >>> >> > ?99% ? ? 86 >>> >> > ?100% ? ?678 (longest request) >>> >> > >>> >> > >>> >> > It seems latency is stabilized by hiding memory reclaim. >>> >> > >>> >> > The score for memory reclaim was following. >>> >> > See patch 10 for meaning of each member. >>> >> > >>> >> > == without async reclaim == >>> >> > recent_scan_success_ratio 44 >>> >> > limit_scan_pages 388463 >>> >> > limit_freed_pages 162238 >>> >> > limit_elapsed_ns 13852159231 >>> >> > soft_scan_pages 0 >>> >> > soft_freed_pages 0 >>> >> > soft_elapsed_ns 0 >>> >> > margin_scan_pages 0 >>> >> > margin_freed_pages 0 >>> >> > margin_elapsed_ns 0 >>> >> > >>> >> > == with async reclaim == >>> >> > recent_scan_success_ratio 6 >>> >> > limit_scan_pages 0 >>> >> > limit_freed_pages 0 >>> >> > limit_elapsed_ns 0 >>> >> > soft_scan_pages 0 >>> >> > soft_freed_pages 0 >>> >> > soft_elapsed_ns 0 >>> >> > margin_scan_pages 1295556 >>> >> > margin_freed_pages 122450 >>> >> > margin_elapsed_ns 644881521 >>> >> > >>> >> > >>> >> > For this case, SCHED_IDLE workqueue can reclaim enough memory to the httpd. >>> >> > >>> >> > I may need to dig why scan_success_ratio is far different in the both case. >>> >> > I guess the difference of epalsed_ns is because several threads enter >>> >> > memory reclaim when async reclaim doesn't run. But may not... >>> >> > >>> >> >>> >> >>> >> Hmm.. I noticed a very strange behavior on a simple test w/ the patch set. >>> >> >>> >> Test: >>> >> I created a 4g memcg and start doing cat. Then the memcg being OOM >>> >> killed as soon as it reaches its hard_limit. We shouldn't hit OOM even >>> >> w/o async-reclaim. >>> >> >>> >> Again, I will read through the patch. But like to post the test result first. >>> >> >>> >> $ echo $$ >/dev/cgroup/memory/A/tasks >>> >> $ cat /dev/cgroup/memory/A/memory.limit_in_bytes >>> >> 4294967296 >>> >> >>> >> $ time cat /export/hdc3/dd_A/tf0 > /dev/zero >>> >> Killed >>> >> >>> > >>> > I did the same kind of test without any problem...but ok, I'll do more test >>> > later. >>> > >>> > >>> > >>> >> real ?0m53.565s >>> >> user ?0m0.061s >>> >> sys ? 0m4.814s >>> >> >>> >> Here is the OOM log: >>> >> >>> >> May 26 18:43:00 ?kernel: [ ?963.489112] cat invoked oom-killer: >>> >> gfp_mask=0xd0, order=0, oom_adj=0, oom_score_adj=0 >>> >> May 26 18:43:00 ?kernel: [ ?963.489121] Pid: 9425, comm: cat Tainted: >>> >> G ? ? ? ?W ? 2.6.39-mcg-DEV #131 >>> >> May 26 18:43:00 ?kernel: [ ?963.489123] Call Trace: >>> >> May 26 18:43:00 ?kernel: [ ?963.489134] ?[] >>> >> dump_header+0x82/0x1af >>> >> May 26 18:43:00 ?kernel: [ ?963.489137] ?[] ? >>> >> spin_lock+0xe/0x10 >>> >> May 26 18:43:00 ?kernel: [ ?963.489140] ?[] ? >>> >> find_lock_task_mm+0x2d/0x67 >>> >> May 26 18:43:00 ?kernel: [ ?963.489143] ?[] >>> >> oom_kill_process+0x50/0x27b >>> >> May 26 18:43:00 ?kernel: [ ?963.489155] ?[] >>> >> mem_cgroup_out_of_memory+0x9a/0xe4 >>> >> May 26 18:43:00 ?kernel: [ ?963.489160] ?[] >>> >> mem_cgroup_handle_oom+0x134/0x1fe >>> >> May 26 18:43:00 ?kernel: [ ?963.489163] ?[] ? >>> >> __mem_cgroup_insert_exceeded+0x83/0x83 >>> >> May 26 18:43:00 ?kernel: [ ?963.489176] ?[] >>> >> __mem_cgroup_try_charge.clone.3+0x368/0x43a >>> >> May 26 18:43:00 ?kernel: [ ?963.489179] ?[] >>> >> mem_cgroup_cache_charge+0x95/0x123 >>> >> May 26 18:43:00 ?kernel: [ ?963.489183] ?[] >>> >> add_to_page_cache_locked+0x42/0x114 >>> >> May 26 18:43:00 ?kernel: [ ?963.489185] ?[] >>> >> add_to_page_cache_lru+0x31/0x5f >>> >> May 26 18:43:00 ?kernel: [ ?963.489189] ?[] >>> >> mpage_readpages+0xb6/0x132 >>> >> May 26 18:43:00 ?kernel: [ ?963.489194] ?[] ? >>> >> noalloc_get_block_write+0x24/0x24 >>> >> May 26 18:43:00 ?kernel: [ ?963.489197] ?[] ? >>> >> noalloc_get_block_write+0x24/0x24 >>> >> May 26 18:43:00 ?kernel: [ ?963.489201] ?[] ? >>> >> __switch_to+0x160/0x212 >>> >> May 26 18:43:00 ?kernel: [ ?963.489205] ?[] >>> >> ext4_readpages+0x1d/0x1f >>> >> May 26 18:43:00 ?kernel: [ ?963.489209] ?[] >>> >> __do_page_cache_readahead+0x144/0x1e3 >>> >> May 26 18:43:00 ?kernel: [ ?963.489212] ?[] >>> >> ra_submit+0x21/0x25 >>> >> May 26 18:43:00 ?kernel: [ ?963.489215] ?[] >>> >> ondemand_readahead+0x18c/0x19f >>> >> May 26 18:43:00 ?kernel: [ ?963.489218] ?[] >>> >> page_cache_async_readahead+0x7d/0x86 >>> >> May 26 18:43:00 ?kernel: [ ?963.489221] ?[] >>> >> generic_file_aio_read+0x2d8/0x5fe >>> >> May 26 18:43:00 ?kernel: [ ?963.489225] ?[] >>> >> do_sync_read+0xcb/0x108 >>> >> May 26 18:43:00 ?kernel: [ ?963.489230] ?[] ? >>> >> fsnotify_perm+0x66/0x72 >>> >> May 26 18:43:00 ?kernel: [ ?963.489233] ?[] ? >>> >> security_file_permission+0x2e/0x33 >>> >> May 26 18:43:00 ?kernel: [ ?963.489236] ?[] >>> >> vfs_read+0xab/0x107 >>> >> May 26 18:43:00 ?kernel: [ ?963.489239] ?[] sys_read+0x4a/0x6e >>> >> May 26 18:43:00 ?kernel: [ ?963.489244] ?[] >>> >> sysenter_dispatch+0x7/0x27 >>> >> May 26 18:43:00 ?kernel: [ ?963.489248] Task in /A killed as a result >>> >> of limit of /A >>> >> May 26 18:43:00 ?kernel: [ ?963.489251] memory: usage 4194304kB, limit >>> >> 4194304kB, failcnt 26 >>> >> May 26 18:43:00 ?kernel: [ ?963.489253] memory+swap: usage 0kB, limit >>> >> 9007199254740991kB, failcnt 0 >>> >> >>> > >>> > Hmm, why memory+swap usage 0kb here... >>> > >>> > In this set, I used mem_cgroup_margin() rather than res_counter_margin(). >>> > Hmm, do you disable swap accounting ? If so, I may miss some. >>> >>> Yes, I disabled the swap accounting in .config: >>> # CONFIG_CGROUP_MEM_RES_CTLR_SWAP is not set >>> >>> >>> Here is how i reproduce it: >>> >>> $ mkdir /dev/cgroup/memory/D >>> $ echo 4g >/dev/cgroup/memory/D/memory.limit_in_bytes >>> >>> $ cat /dev/cgroup/memory/D/memory.limit_in_bytes >>> 4294967296 >>> >>> $ cat /dev/cgroup/memory/D/memory. >>> memory.async_control ? ? ? ? ? ? memory.max_usage_in_bytes >>> memory.soft_limit_in_bytes ? ? ? memory.use_hierarchy >>> memory.failcnt ? ? ? ? ? ? ? ? ? memory.move_charge_at_immigrate >>> memory.stat >>> memory.force_empty ? ? ? ? ? ? ? memory.oom_control >>> memory.swappiness >>> memory.limit_in_bytes ? ? ? ? ? ?memory.reclaim_stat >>> memory.usage_in_bytes >>> >>> $ cat /dev/cgroup/memory/D/memory.async_control >>> 0 >>> $ echo 1 >/dev/cgroup/memory/D/memory.async_control >>> $ cat /dev/cgroup/memory/D/memory.async_control >>> 1 >>> >>> $ echo $$ >/dev/cgroup/memory/D/tasks >>> $ cat /proc/4358/cgroup >>> 3:memory:/D >>> >>> $ time cat /export/hdc3/dd_A/tf0 > /dev/zero >>> Killed >>> >> >> If you applied my patches collectly, async_control can be seen if >> swap controller is configured because of BUG in patch. > > I noticed the BUG at the very beginning, so all my tests are having the fix. > >> >> I could cat 20G file under 4G limit without any problem with boot option >> swapaccount=0. no problem if async_control == 0 ? > > $ cat /dev/cgroup/memory/D/memory.async_control > 1 > > I have the .config > # CONFIG_CGROUP_MEM_RES_CTLR_SWAP is not set > > Not sure if that makes difference. I will test next to turn that on. I know what's the problem and also verified. Our configuration might differs on the "#if MAX_NUMNODES > 1" Please apply the following patch: diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6a52699..0b88d71 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1217,7 +1217,7 @@ unsigned long mem_cgroup_zone_reclaimable_pages(struct mem_cgroup *memcg, struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); nr = MEM_CGROUP_ZSTAT(mz, NR_ACTIVE_FILE) + - MEM_CGROUP_ZSTAT(mz, NR_ACTIVE_FILE); + MEM_CGROUP_ZSTAT(mz, NR_INACTIVE_FILE); if (nr_swap_pages > 0) nr += MEM_CGROUP_ZSTAT(mz, NR_ACTIVE_ANON) + MEM_CGROUP_ZSTAT(mz, NR_INACTIVE_ANON); --Ying > > --Ying > > >> >> >> >> Thanks, >> -Kame >> >> >> >> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/