From: Fengguang Wu <fengguang.wu@intel.com> To: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Sha Zhengju <handai.szj@gmail.com>, linux-mm@kvack.org, cgroups@vger.kernel.org, gthelen@google.com, yinghan@google.com, akpm@linux-foundation.org, mhocko@suse.cz, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, Sha Zhengju <handai.szj@taobao.com> Subject: Re: [PATCH 3/7] Make TestSetPageDirty and dirty page accounting in one func Date: Sat, 7 Jul 2012 22:42:28 +0800 [thread overview] Message-ID: <20120707144228.GA24329@localhost> (raw) In-Reply-To: <4FF1827A.7060806@jp.fujitsu.com> On Mon, Jul 02, 2012 at 08:14:02PM +0900, KAMEZAWA Hiroyuki wrote: > (2012/06/28 20:01), Sha Zhengju wrote: > > From: Sha Zhengju <handai.szj@taobao.com> > > > > Commit a8e7d49a(Fix race in create_empty_buffers() vs __set_page_dirty_buffers()) > > extracts TestSetPageDirty from __set_page_dirty and is far away from > > account_page_dirtied.But it's better to make the two operations in one single > > function to keep modular.So in order to avoid the potential race mentioned in > > commit a8e7d49a, we can hold private_lock until __set_page_dirty completes. > > I guess there's no deadlock between ->private_lock and ->tree_lock by quick look. > > > > It's a prepare patch for following memcg dirty page accounting patches. > > > > Signed-off-by: Sha Zhengju <handai.szj@taobao.com> > > I think there is no problem with the lock order. Me think so, too. > My small concern is the impact on the performance. IIUC, lock contention here can be > seen if multiple threads write to the same file in parallel. > Do you have any numbers before/after the patch ? That would be a worthwhile test. The patch moves ->tree_lock and ->i_lock into ->private_lock, these are often contented locks.. For example, in the below case of 12 hard disks, each running 1 dd write, the ->tree_lock and ->private_lock have the top #1 and #2 contentions. lkp-nex04/JBOD-12HDD-thresh=1000M/ext4-1dd-1-3.3.0/lock_stat ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- &(&mapping->tree_lock)->rlock: 18629034 19138284 0.09 1029.32 24353812.07 49650988 482883410 0.11 186.88 260706119.09 ----------------------------- &(&mapping->tree_lock)->rlock 783 [<ffffffff81109267>] tag_pages_for_writeback+0x2b/0x9d &(&mapping->tree_lock)->rlock 3195817 [<ffffffff81100d6c>] add_to_page_cache_locked+0xa3/0x119 &(&mapping->tree_lock)->rlock 3863710 [<ffffffff81108df7>] test_set_page_writeback+0x63/0x140 &(&mapping->tree_lock)->rlock 3311518 [<ffffffff81172ade>] __set_page_dirty+0x25/0xa5 ----------------------------- &(&mapping->tree_lock)->rlock 3450725 [<ffffffff81100d6c>] add_to_page_cache_locked+0xa3/0x119 &(&mapping->tree_lock)->rlock 3225542 [<ffffffff81172ade>] __set_page_dirty+0x25/0xa5 &(&mapping->tree_lock)->rlock 2241958 [<ffffffff81108df7>] test_set_page_writeback+0x63/0x140 &(&mapping->tree_lock)->rlock 7339603 [<ffffffff8110ac33>] test_clear_page_writeback+0x64/0x155 ............................................................................................................................................................................................... &(&mapping->private_lock)->rlock: 1165199 1191201 0.11 2843.25 1621608.38 13341420 152761848 0.10 3727.92 33559035.07 -------------------------------- &(&mapping->private_lock)->rlock 1 [<ffffffff81172913>] __find_get_block_slow+0x5a/0x135 &(&mapping->private_lock)->rlock 385576 [<ffffffff811735d6>] create_empty_buffers+0x48/0xbf &(&mapping->private_lock)->rlock 805624 [<ffffffff8117346d>] try_to_free_buffers+0x57/0xaa -------------------------------- &(&mapping->private_lock)->rlock 1 [<ffffffff811746dd>] __getblk+0x1b8/0x257 &(&mapping->private_lock)->rlock 952718 [<ffffffff8117346d>] try_to_free_buffers+0x57/0xaa &(&mapping->private_lock)->rlock 238482 [<ffffffff811735d6>] create_empty_buffers+0x48/0xbf Thanks, Fengguang
WARNING: multiple messages have this Message-ID (diff)
From: Fengguang Wu <fengguang.wu@intel.com> To: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Sha Zhengju <handai.szj@gmail.com>, linux-mm@kvack.org, cgroups@vger.kernel.org, gthelen@google.com, yinghan@google.com, akpm@linux-foundation.org, mhocko@suse.cz, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, Sha Zhengju <handai.szj@taobao.com> Subject: Re: [PATCH 3/7] Make TestSetPageDirty and dirty page accounting in one func Date: Sat, 7 Jul 2012 22:42:28 +0800 [thread overview] Message-ID: <20120707144228.GA24329@localhost> (raw) In-Reply-To: <4FF1827A.7060806@jp.fujitsu.com> On Mon, Jul 02, 2012 at 08:14:02PM +0900, KAMEZAWA Hiroyuki wrote: > (2012/06/28 20:01), Sha Zhengju wrote: > > From: Sha Zhengju <handai.szj@taobao.com> > > > > Commit a8e7d49a(Fix race in create_empty_buffers() vs __set_page_dirty_buffers()) > > extracts TestSetPageDirty from __set_page_dirty and is far away from > > account_page_dirtied.But it's better to make the two operations in one single > > function to keep modular.So in order to avoid the potential race mentioned in > > commit a8e7d49a, we can hold private_lock until __set_page_dirty completes. > > I guess there's no deadlock between ->private_lock and ->tree_lock by quick look. > > > > It's a prepare patch for following memcg dirty page accounting patches. > > > > Signed-off-by: Sha Zhengju <handai.szj@taobao.com> > > I think there is no problem with the lock order. Me think so, too. > My small concern is the impact on the performance. IIUC, lock contention here can be > seen if multiple threads write to the same file in parallel. > Do you have any numbers before/after the patch ? That would be a worthwhile test. The patch moves ->tree_lock and ->i_lock into ->private_lock, these are often contented locks.. For example, in the below case of 12 hard disks, each running 1 dd write, the ->tree_lock and ->private_lock have the top #1 and #2 contentions. lkp-nex04/JBOD-12HDD-thresh=1000M/ext4-1dd-1-3.3.0/lock_stat ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- &(&mapping->tree_lock)->rlock: 18629034 19138284 0.09 1029.32 24353812.07 49650988 482883410 0.11 186.88 260706119.09 ----------------------------- &(&mapping->tree_lock)->rlock 783 [<ffffffff81109267>] tag_pages_for_writeback+0x2b/0x9d &(&mapping->tree_lock)->rlock 3195817 [<ffffffff81100d6c>] add_to_page_cache_locked+0xa3/0x119 &(&mapping->tree_lock)->rlock 3863710 [<ffffffff81108df7>] test_set_page_writeback+0x63/0x140 &(&mapping->tree_lock)->rlock 3311518 [<ffffffff81172ade>] __set_page_dirty+0x25/0xa5 ----------------------------- &(&mapping->tree_lock)->rlock 3450725 [<ffffffff81100d6c>] add_to_page_cache_locked+0xa3/0x119 &(&mapping->tree_lock)->rlock 3225542 [<ffffffff81172ade>] __set_page_dirty+0x25/0xa5 &(&mapping->tree_lock)->rlock 2241958 [<ffffffff81108df7>] test_set_page_writeback+0x63/0x140 &(&mapping->tree_lock)->rlock 7339603 [<ffffffff8110ac33>] test_clear_page_writeback+0x64/0x155 ............................................................................................................................................................................................... &(&mapping->private_lock)->rlock: 1165199 1191201 0.11 2843.25 1621608.38 13341420 152761848 0.10 3727.92 33559035.07 -------------------------------- &(&mapping->private_lock)->rlock 1 [<ffffffff81172913>] __find_get_block_slow+0x5a/0x135 &(&mapping->private_lock)->rlock 385576 [<ffffffff811735d6>] create_empty_buffers+0x48/0xbf &(&mapping->private_lock)->rlock 805624 [<ffffffff8117346d>] try_to_free_buffers+0x57/0xaa -------------------------------- &(&mapping->private_lock)->rlock 1 [<ffffffff811746dd>] __getblk+0x1b8/0x257 &(&mapping->private_lock)->rlock 952718 [<ffffffff8117346d>] try_to_free_buffers+0x57/0xaa &(&mapping->private_lock)->rlock 238482 [<ffffffff811735d6>] create_empty_buffers+0x48/0xbf Thanks, Fengguang -- 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2012-07-07 14:42 UTC|newest] Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-06-28 10:54 [PATCH 0/7] Per-cgroup page stat accounting Sha Zhengju 2012-06-28 10:54 ` Sha Zhengju 2012-06-28 10:54 ` Sha Zhengju 2012-06-28 10:57 ` [PATCH 1/7] memcg: update cgroup memory document Sha Zhengju 2012-06-28 10:57 ` Sha Zhengju 2012-06-28 10:57 ` Sha Zhengju 2012-07-02 7:00 ` Kamezawa Hiroyuki 2012-07-02 7:00 ` Kamezawa Hiroyuki 2012-07-04 12:47 ` Michal Hocko 2012-07-04 12:47 ` Michal Hocko 2012-07-04 12:47 ` Michal Hocko 2012-07-07 13:45 ` Fengguang Wu 2012-07-07 13:45 ` Fengguang Wu 2012-07-07 13:45 ` Fengguang Wu 2012-06-28 10:58 ` [PATCH 2/7] memcg: remove MEMCG_NR_FILE_MAPPED Sha Zhengju 2012-06-28 10:58 ` Sha Zhengju 2012-07-02 10:44 ` Kamezawa Hiroyuki 2012-07-02 10:44 ` Kamezawa Hiroyuki 2012-07-02 10:44 ` Kamezawa Hiroyuki 2012-07-04 12:56 ` Michal Hocko 2012-07-04 12:56 ` Michal Hocko 2012-07-04 12:58 ` Michal Hocko 2012-07-04 12:58 ` Michal Hocko 2012-07-04 12:58 ` Michal Hocko 2012-07-07 13:48 ` Fengguang Wu 2012-07-07 13:48 ` Fengguang Wu 2012-07-09 21:01 ` Greg Thelen 2012-07-09 21:01 ` Greg Thelen 2012-07-09 21:01 ` Greg Thelen 2012-07-11 8:00 ` Sha Zhengju 2012-07-11 8:00 ` Sha Zhengju 2012-06-28 11:01 ` [PATCH 3/7] Make TestSetPageDirty and dirty page accounting in one func Sha Zhengju 2012-06-28 11:01 ` Sha Zhengju 2012-07-02 11:14 ` Kamezawa Hiroyuki 2012-07-02 11:14 ` Kamezawa Hiroyuki 2012-07-02 11:14 ` Kamezawa Hiroyuki 2012-07-07 14:42 ` Fengguang Wu [this message] 2012-07-07 14:42 ` Fengguang Wu 2012-07-04 14:23 ` Michal Hocko 2012-07-04 14:23 ` Michal Hocko 2012-06-28 11:03 ` [PATCH 4/7] Use vfs __set_page_dirty interface instead of doing it inside filesystem Sha Zhengju 2012-06-28 11:03 ` Sha Zhengju 2012-06-28 11:03 ` Sha Zhengju 2012-06-29 5:21 ` Sage Weil 2012-06-29 5:21 ` Sage Weil 2012-06-29 5:21 ` Sage Weil 2012-07-02 8:10 ` Sha Zhengju 2012-07-02 8:10 ` Sha Zhengju 2012-07-02 14:49 ` Sage Weil 2012-07-02 14:49 ` Sage Weil 2012-07-04 8:11 ` Sha Zhengju 2012-07-04 8:11 ` Sha Zhengju 2012-07-05 15:20 ` Sage Weil 2012-07-05 15:20 ` Sage Weil 2012-07-05 15:40 ` Sha Zhengju 2012-07-05 15:40 ` Sha Zhengju 2012-07-04 14:27 ` Michal Hocko 2012-07-04 14:27 ` Michal Hocko 2012-06-28 11:04 ` [PATCH 5/7] memcg: add per cgroup dirty pages accounting Sha Zhengju 2012-06-28 11:04 ` Sha Zhengju 2012-06-28 11:04 ` Sha Zhengju 2012-07-03 5:57 ` Kamezawa Hiroyuki 2012-07-03 5:57 ` Kamezawa Hiroyuki 2012-07-08 14:45 ` Fengguang Wu 2012-07-08 14:45 ` Fengguang Wu 2012-07-04 16:11 ` Michal Hocko 2012-07-04 16:11 ` Michal Hocko 2012-07-04 16:11 ` Michal Hocko 2012-07-09 21:02 ` Greg Thelen 2012-07-09 21:02 ` Greg Thelen 2012-07-11 9:32 ` Sha Zhengju 2012-07-11 9:32 ` Sha Zhengju 2012-07-19 6:33 ` Kamezawa Hiroyuki 2012-07-19 6:33 ` Kamezawa Hiroyuki 2012-07-19 6:33 ` Kamezawa Hiroyuki 2012-06-28 11:05 ` [PATCH 6/7] memcg: add per cgroup writeback " Sha Zhengju 2012-06-28 11:05 ` Sha Zhengju 2012-07-03 6:31 ` Kamezawa Hiroyuki 2012-07-03 6:31 ` Kamezawa Hiroyuki 2012-07-04 8:24 ` Sha Zhengju 2012-07-04 8:24 ` Sha Zhengju 2012-07-08 14:44 ` Fengguang Wu 2012-07-08 14:44 ` Fengguang Wu 2012-07-08 23:01 ` Johannes Weiner 2012-07-08 23:01 ` Johannes Weiner 2012-07-09 1:37 ` Fengguang Wu 2012-07-09 1:37 ` Fengguang Wu 2012-07-09 1:37 ` Fengguang Wu 2012-07-04 16:15 ` Michal Hocko 2012-07-04 16:15 ` Michal Hocko 2012-06-28 11:06 ` Sha Zhengju 2012-06-28 11:06 ` Sha Zhengju 2012-06-28 11:06 ` Sha Zhengju 2012-07-08 14:53 ` Fengguang Wu 2012-07-08 14:53 ` Fengguang Wu 2012-07-08 14:53 ` Fengguang Wu 2012-07-09 3:36 ` Sha Zhengju 2012-07-09 3:36 ` Sha Zhengju 2012-07-09 3:36 ` Sha Zhengju 2012-07-09 4:14 ` Fengguang Wu 2012-07-09 4:14 ` Fengguang Wu 2012-07-09 4:14 ` Fengguang Wu 2012-07-09 4:18 ` Kamezawa Hiroyuki 2012-07-09 4:18 ` Kamezawa Hiroyuki 2012-07-09 5:22 ` Sha Zhengju 2012-07-09 5:22 ` Sha Zhengju 2012-07-09 5:22 ` Sha Zhengju 2012-07-09 5:28 ` Fengguang Wu 2012-07-09 5:28 ` Fengguang Wu 2012-07-09 5:28 ` Fengguang Wu 2012-07-09 5:19 ` Sha Zhengju 2012-07-09 5:19 ` Sha Zhengju 2012-07-09 5:25 ` Fengguang Wu 2012-07-09 5:25 ` Fengguang Wu 2012-07-09 21:02 ` Greg Thelen 2012-07-09 21:02 ` Greg Thelen 2012-06-28 11:06 ` [PATCH 7/7] memcg: print more detailed info while memcg oom happening Sha Zhengju 2012-06-28 11:06 ` Sha Zhengju 2012-06-28 11:06 ` Sha Zhengju 2012-07-04 8:25 ` Sha Zhengju 2012-07-04 8:25 ` Sha Zhengju 2012-07-04 8:25 ` Sha Zhengju 2012-07-04 8:29 ` Kamezawa Hiroyuki 2012-07-04 8:29 ` Kamezawa Hiroyuki 2012-07-04 11:20 ` Sha Zhengju 2012-07-04 11:20 ` Sha Zhengju 2012-07-04 11:20 ` Sha Zhengju 2012-06-29 8:23 ` [PATCH 0/7] Per-cgroup page stat accounting Kamezawa Hiroyuki 2012-06-29 8:23 ` Kamezawa Hiroyuki 2012-07-02 7:51 ` Sha Zhengju 2012-07-02 7:51 ` Sha Zhengju 2012-07-02 7:51 ` Sha Zhengju
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20120707144228.GA24329@localhost \ --to=fengguang.wu@intel.com \ --cc=akpm@linux-foundation.org \ --cc=cgroups@vger.kernel.org \ --cc=gthelen@google.com \ --cc=handai.szj@gmail.com \ --cc=handai.szj@taobao.com \ --cc=kamezawa.hiroyu@jp.fujitsu.com \ --cc=linux-fsdevel@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=mhocko@suse.cz \ --cc=torvalds@linux-foundation.org \ --cc=viro@zeniv.linux.org.uk \ --cc=yinghan@google.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.