From: Mike Galbraith <efault@gmx.de>
To: Mel Gorman <mgorman@techsingularity.net>,
"Darrick J. Wong" <djwong@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
NeilBrown <neilb@suse.de>, Theodore Ts'o <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
Matthew Wilcox <willy@infradead.org>,
Michal Hocko <mhocko@suse.com>,
Dave Chinner <david@fromorbit.com>,
Rik van Riel <riel@surriel.com>, Vlastimil Babka <vbabka@suse.cz>,
Johannes Weiner <hannes@cmpxchg.org>,
Jonathan Corbet <corbet@lwn.net>, Linux-MM <linux-mm@kvack.org>,
Linux-fsdevel <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made
Date: Wed, 24 Nov 2021 18:24:21 +0100 [thread overview]
Message-ID: <2035e3e639ac13e4a3be770f3567f244e88b66f4.camel@gmx.de> (raw)
In-Reply-To: <20211124103221.GD3366@techsingularity.net>
On Wed, 2021-11-24 at 10:32 +0000, Mel Gorman wrote:
> On Tue, Nov 23, 2021 at 05:19:12PM -0800, Darrick J. Wong wrote:
>
> > AFAICT the system is mostly idle, but it's difficult to tell because ps
> > and top also get stuck waiting for this cgroup for whatever reason.
>
> But this is surprising because I expect that ps and top are not running
> within the cgroup. Was /proc/PID/stack readable?
Probably this.
crash> ps | grep UN
4418 4417 4 ffff8881cae66e40 UN 0.0 7620 980 memcg_test_1 <== the bad guy
4419 4417 6 ffff8881cae62f40 UN 0.0 7620 980 memcg_test_1
4420 4417 5 ffff8881cae65e80 UN 0.0 7620 980 memcg_test_1
4421 4417 7 ffff8881cae63f00 UN 0.0 7620 980 memcg_test_1
4422 4417 4 ffff8881cae60000 UN 0.0 7620 980 memcg_test_1
4423 4417 3 ffff888128985e80 UN 0.0 7620 980 memcg_test_1
4424 4417 7 ffff888117f79f80 UN 0.0 7620 980 memcg_test_1
4425 4417 2 ffff888117f7af40 UN 0.0 7620 980 memcg_test_1
4428 2791 6 ffff8881a8253f00 UN 0.0 38868 3568 ps
4429 2808 4 ffff888100c90000 UN 0.0 38868 3600 ps
crash> bt -sx 4429
PID: 4429 TASK: ffff888100c90000 CPU: 4 COMMAND: "ps"
#0 [ffff8881af1c3ce0] __schedule+0x285 at ffffffff817ae6c5
#1 [ffff8881af1c3d68] schedule+0x3a at ffffffff817aed4a
#2 [ffff8881af1c3d78] rwsem_down_read_slowpath+0x197 at ffffffff817b11a7
#3 [ffff8881af1c3e08] down_read_killable+0x5c at ffffffff817b142c
#4 [ffff8881af1c3e18] down_read_killable+0x5c at ffffffff817b142c
#5 [ffff8881af1c3e28] __access_remote_vm+0x3f at ffffffff8120131f
#6 [ffff8881af1c3e90] proc_pid_cmdline_read+0x148 at ffffffff812fc9a8
#7 [ffff8881af1c3ee8] vfs_read+0x92 at ffffffff8126a302
#8 [ffff8881af1c3f00] ksys_read+0x7d at ffffffff8126a72d
#9 [ffff8881af1c3f38] do_syscall_64+0x37 at ffffffff817a3f57
#10 [ffff8881af1c3f50] entry_SYSCALL_64_after_hwframe+0x44 at ffffffff8180007c
RIP: 00007f4b50fe8b5e RSP: 00007ffdd7f6fe38 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007f4b5186a010 RCX: 00007f4b50fe8b5e
RDX: 0000000000020000 RSI: 00007f4b5186a010 RDI: 0000000000000006
RBP: 0000000000020000 R8: 0000000000000007 R9: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4b5186a010
R13: 0000000000000000 R14: 0000000000000006 R15: 0000000000000000
ORIG_RAX: 0000000000000000 CS: 0033 SS: 002b
crash> mm_struct -x ffff8881021b4800
struct mm_struct {
{
mmap = 0xffff8881ccfe6a80,
mm_rb = {
rb_node = 0xffff8881ccfe61a0
},
...
mmap_lock = {
count = {
counter = 0x3
},
owner = {
counter = 0xffff8881cae66e40
...
crash> bt 0xffff8881cae66e40
PID: 4418 TASK: ffff8881cae66e40 CPU: 4 COMMAND: "memcg_test_1"
#0 [ffff888154097a88] __schedule at ffffffff817ae6c5
#1 [ffff888154097b10] schedule at ffffffff817aed4a
#2 [ffff888154097b20] schedule_timeout at ffffffff817b311f
#3 [ffff888154097b90] reclaim_throttle at ffffffff811d802b
#4 [ffff888154097bf0] do_try_to_free_pages at ffffffff811da206
#5 [ffff888154097c40] try_to_free_mem_cgroup_pages at ffffffff811db522
#6 [ffff888154097cd0] try_charge_memcg at ffffffff81256440
#7 [ffff888154097d60] obj_cgroup_charge_pages at ffffffff81256c97
#8 [ffff888154097d88] obj_cgroup_charge at ffffffff8125898c
#9 [ffff888154097da8] kmem_cache_alloc at ffffffff81242099
#10 [ffff888154097de0] vm_area_alloc at ffffffff8106c87a
#11 [ffff888154097df0] mmap_region at ffffffff812082b2
#12 [ffff888154097e58] do_mmap at ffffffff81208922
#13 [ffff888154097eb0] vm_mmap_pgoff at ffffffff811e259f
#14 [ffff888154097f38] do_syscall_64 at ffffffff817a3f57
#15 [ffff888154097f50] entry_SYSCALL_64_after_hwframe at
ffffffff8180007c
RIP: 00007f211c36b743 RSP: 00007ffeaac1bd58 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f211c36b743
RDX: 0000000000000003 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000000
R10: 0000000000002022 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000001000 R14: 0000000000002022 R15: 0000000000000000
ORIG_RAX: 0000000000000009 CS: 0033 SS: 002b
crash>
next prev parent reply other threads:[~2021-11-24 17:24 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-22 14:46 [PATCH v5 0/8] Remove dependency on congestion_wait in mm/ Mel Gorman
2021-10-22 14:46 ` [PATCH 1/8] mm/vmscan: Throttle reclaim until some writeback completes if congested Mel Gorman
2021-10-22 14:46 ` [PATCH 2/8] mm/vmscan: Throttle reclaim and compaction when too may pages are isolated Mel Gorman
2021-10-22 14:46 ` [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made Mel Gorman
2021-11-24 1:19 ` Darrick J. Wong
2021-11-24 1:49 ` Darrick J. Wong
2021-11-24 14:35 ` Mel Gorman
2021-11-24 18:02 ` Darrick J. Wong
2021-11-24 10:32 ` Mel Gorman
2021-11-24 10:43 ` Vlastimil Babka
2021-11-24 10:53 ` Mel Gorman
2021-11-24 17:24 ` Mike Galbraith [this message]
2021-10-22 14:46 ` [PATCH 4/8] mm/writeback: Throttle based on page writeback instead of congestion Mel Gorman
2021-10-22 14:46 ` [PATCH 5/8] mm/page_alloc: Remove the throttling logic from the page allocator Mel Gorman
2021-10-25 10:07 ` Vlastimil Babka
2021-10-22 14:46 ` [PATCH 6/8] mm/vmscan: Centralise timeout values for reclaim_throttle Mel Gorman
2021-10-22 14:46 ` [PATCH 7/8] mm/vmscan: Increase the timeout if page reclaim is not making progress Mel Gorman
2021-10-22 14:46 ` [PATCH 8/8] mm/vmscan: Delay waking of tasks throttled on NOPROGRESS Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2021-10-19 9:01 [PATCH v4 0/8] Remove dependency on congestion_wait in mm/ Mel Gorman
2021-10-19 9:01 ` [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made Mel Gorman
2021-10-08 13:53 [PATCH v3 0/8] Remove dependency on congestion_wait in mm/ Mel Gorman
2021-10-08 13:53 ` [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made Mel Gorman
2021-10-14 12:31 ` Vlastimil Babka
2021-10-14 13:03 ` Mel Gorman
2021-10-14 15:45 ` Vlastimil Babka
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