diff mbox series

[v2] mm, oom: make the calculation of oom badness more accurate

Message ID 1594309987-9919-1-git-send-email-laoar.shao@gmail.com (mailing list archive)
State New, archived
Headers show
Series [v2] mm, oom: make the calculation of oom badness more accurate | expand

Commit Message

Yafang Shao July 9, 2020, 3:53 p.m. UTC 
Recently we found an issue on our production environment that when memcg
oom is triggered the oom killer doesn't chose the process with largest
resident memory but chose the first scanned process. Note that all
processes in this memcg have the same oom_score_adj, so the oom killer
should chose the process with largest resident memory.

Bellow is part of the oom info, which is enough to analyze this issue.
[7516987.983223] memory: usage 16777216kB, limit 16777216kB, failcnt 52843037
[7516987.983224] memory+swap: usage 16777216kB, limit 9007199254740988kB, failcnt 0
[7516987.983225] kmem: usage 301464kB, limit 9007199254740988kB, failcnt 0
[...]
[7516987.983293] [ pid ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
[7516987.983510] [ 5740]     0  5740      257        1    32768        0          -998 pause
[7516987.983574] [58804]     0 58804     4594      771    81920        0          -998 entry_point.bas
[7516987.983577] [58908]     0 58908     7089      689    98304        0          -998 cron
[7516987.983580] [58910]     0 58910    16235     5576   163840        0          -998 supervisord
[7516987.983590] [59620]     0 59620    18074     1395   188416        0          -998 sshd
[7516987.983594] [59622]     0 59622    18680     6679   188416        0          -998 python
[7516987.983598] [59624]     0 59624  1859266     5161   548864        0          -998 odin-agent
[7516987.983600] [59625]     0 59625   707223     9248   983040        0          -998 filebeat
[7516987.983604] [59627]     0 59627   416433    64239   774144        0          -998 odin-log-agent
[7516987.983607] [59631]     0 59631   180671    15012   385024        0          -998 python3
[7516987.983612] [61396]     0 61396   791287     3189   352256        0          -998 client
[7516987.983615] [61641]     0 61641  1844642    29089   946176        0          -998 client
[7516987.983765] [ 9236]     0  9236     2642      467    53248        0          -998 php_scanner
[7516987.983911] [42898]     0 42898    15543      838   167936        0          -998 su
[7516987.983915] [42900]  1000 42900     3673      867    77824        0          -998 exec_script_vr2
[7516987.983918] [42925]  1000 42925    36475    19033   335872        0          -998 python
[7516987.983921] [57146]  1000 57146     3673      848    73728        0          -998 exec_script_J2p
[7516987.983925] [57195]  1000 57195   186359    22958   491520        0          -998 python2
[7516987.983928] [58376]  1000 58376   275764    14402   290816        0          -998 rosmaster
[7516987.983931] [58395]  1000 58395   155166     4449   245760        0          -998 rosout
[7516987.983935] [58406]  1000 58406 18285584  3967322 37101568        0          -998 data_sim
[7516987.984221] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=3aa16c9482ae3a6f6b78bda68a55d32c87c99b985e0f11331cddf05af6c4d753,mems_allowed=0-1,oom_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184,task_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184/1f246a3eeea8f70bf91141eeaf1805346a666e225f823906485ea0b6c37dfc3d,task=pause,pid=5740,uid=0
[7516987.984254] Memory cgroup out of memory: Killed process 5740 (pause) total-vm:1028kB, anon-rss:4kB, file-rss:0kB, shmem-rss:0kB
[7516988.092344] oom_reaper: reaped process 5740 (pause), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB

We can find that the first scanned process 5740 (pause) was killed, but its
rss is only one page. That is because, when we calculate the oom badness in
oom_badness(), we always ignore the negtive point and convert all of these
negtive points to 1. Now as oom_score_adj of all the processes in this
targeted memcg have the same value -998, the points of these processes are
all negtive value. As a result, the first scanned process will be killed.

The oom_socre_adj (-998) in this memcg is set by kubelet, because it is a
a Guaranteed pod, which has higher priority to prevent from being killed by
system oom.

To fix this issue, we should make the calculation of oom point more
accurate. We can achieve it by convert the chosen_point from 'unsigned
long' to 'long'.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 drivers/tty/sysrq.c |  1 +
 fs/proc/base.c      |  7 ++++++-
 include/linux/oom.h |  4 ++--
 mm/memcontrol.c     |  1 +
 mm/oom_kill.c       | 19 ++++++++-----------
 mm/page_alloc.c     |  1 +
 6 files changed, 19 insertions(+), 14 deletions(-)

Comments

Michal Hocko July 10, 2020, 12:10 p.m. UTC | #1 
On Thu 09-07-20 11:53:07, Yafang Shao wrote:
> Recently we found an issue on our production environment that when memcg
> oom is triggered the oom killer doesn't chose the process with largest
> resident memory but chose the first scanned process. Note that all
> processes in this memcg have the same oom_score_adj, so the oom killer
> should chose the process with largest resident memory.
> 
> Bellow is part of the oom info, which is enough to analyze this issue.
> [7516987.983223] memory: usage 16777216kB, limit 16777216kB, failcnt 52843037
> [7516987.983224] memory+swap: usage 16777216kB, limit 9007199254740988kB, failcnt 0
> [7516987.983225] kmem: usage 301464kB, limit 9007199254740988kB, failcnt 0
> [...]
> [7516987.983293] [ pid ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
> [7516987.983510] [ 5740]     0  5740      257        1    32768        0          -998 pause
> [7516987.983574] [58804]     0 58804     4594      771    81920        0          -998 entry_point.bas
> [7516987.983577] [58908]     0 58908     7089      689    98304        0          -998 cron
> [7516987.983580] [58910]     0 58910    16235     5576   163840        0          -998 supervisord
> [7516987.983590] [59620]     0 59620    18074     1395   188416        0          -998 sshd
> [7516987.983594] [59622]     0 59622    18680     6679   188416        0          -998 python
> [7516987.983598] [59624]     0 59624  1859266     5161   548864        0          -998 odin-agent
> [7516987.983600] [59625]     0 59625   707223     9248   983040        0          -998 filebeat
> [7516987.983604] [59627]     0 59627   416433    64239   774144        0          -998 odin-log-agent
> [7516987.983607] [59631]     0 59631   180671    15012   385024        0          -998 python3
> [7516987.983612] [61396]     0 61396   791287     3189   352256        0          -998 client
> [7516987.983615] [61641]     0 61641  1844642    29089   946176        0          -998 client
> [7516987.983765] [ 9236]     0  9236     2642      467    53248        0          -998 php_scanner
> [7516987.983911] [42898]     0 42898    15543      838   167936        0          -998 su
> [7516987.983915] [42900]  1000 42900     3673      867    77824        0          -998 exec_script_vr2
> [7516987.983918] [42925]  1000 42925    36475    19033   335872        0          -998 python
> [7516987.983921] [57146]  1000 57146     3673      848    73728        0          -998 exec_script_J2p
> [7516987.983925] [57195]  1000 57195   186359    22958   491520        0          -998 python2
> [7516987.983928] [58376]  1000 58376   275764    14402   290816        0          -998 rosmaster
> [7516987.983931] [58395]  1000 58395   155166     4449   245760        0          -998 rosout
> [7516987.983935] [58406]  1000 58406 18285584  3967322 37101568        0          -998 data_sim
> [7516987.984221] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=3aa16c9482ae3a6f6b78bda68a55d32c87c99b985e0f11331cddf05af6c4d753,mems_allowed=0-1,oom_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184,task_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184/1f246a3eeea8f70bf91141eeaf1805346a666e225f823906485ea0b6c37dfc3d,task=pause,pid=5740,uid=0
> [7516987.984254] Memory cgroup out of memory: Killed process 5740 (pause) total-vm:1028kB, anon-rss:4kB, file-rss:0kB, shmem-rss:0kB
> [7516988.092344] oom_reaper: reaped process 5740 (pause), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> 
> We can find that the first scanned process 5740 (pause) was killed, but its
> rss is only one page. That is because, when we calculate the oom badness in
> oom_badness(), we always ignore the negtive point and convert all of these
> negtive points to 1. Now as oom_score_adj of all the processes in this
> targeted memcg have the same value -998, the points of these processes are
> all negtive value. As a result, the first scanned process will be killed.
> 
> The oom_socre_adj (-998) in this memcg is set by kubelet, because it is a
> a Guaranteed pod, which has higher priority to prevent from being killed by
> system oom.
> 
> To fix this issue, we should make the calculation of oom point more
> accurate. We can achieve it by convert the chosen_point from 'unsigned
> long' to 'long'.
> 
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---
>  drivers/tty/sysrq.c |  1 +
>  fs/proc/base.c      |  7 ++++++-
>  include/linux/oom.h |  4 ++--
>  mm/memcontrol.c     |  1 +
>  mm/oom_kill.c       | 19 ++++++++-----------
>  mm/page_alloc.c     |  1 +
>  6 files changed, 19 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
> index 7c95afa9..e83fd46 100644
> --- a/drivers/tty/sysrq.c
> +++ b/drivers/tty/sysrq.c
> @@ -382,6 +382,7 @@ static void moom_callback(struct work_struct *ignored)
>  		.memcg = NULL,
>  		.gfp_mask = gfp_mask,
>  		.order = -1,
> +		.chosen_points = LONG_MIN,

It would be better to do the initialization only once when we start
evaluating tasks (select_bad_process).

>  	};
>  
>  	mutex_lock(&oom_lock);
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index d86c0af..bf16406 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -551,8 +551,13 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
>  {
>  	unsigned long totalpages = totalram_pages() + total_swap_pages;
>  	unsigned long points = 0;
> +	long badness;
>  
> -	points = oom_badness(task, totalpages) * 1000 / totalpages;
> +	badness = oom_badness(task, totalpages);
> +	if (badness != LONG_MIN) {
> +		/* Let's keep the range of points as [0, 2000]. */
> +		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
> +	}
>  	seq_printf(m, "%lu\n", points);

This doesn't really work for OOM_SCORE_ADJ_MIN cases because they
will simply print LONG_MIN rather than 0.

So you want
	/*
	 * Special case OOM_SCORE_ADJ_MIN for all others scale the
	 * badness value into [0, 2000] range which we have been
	 * exporting for a long time so userspace might depend on it
	 */
	if (badness == LONG_MIN)
		badness = 0;
	else
		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3

FTR. In my other email I was proposing to scale usage to the [-1000, 1000]
range by
	points = adj + usage * 1000/ totalpages

this would make the math slightly easier to follow but then I've
realized that this would be much less precise so what you have is
better. Btw. we used to do that in the past until a7f638f999ff4
which has changed that for this very reason.

> @@ -107,7 +107,7 @@ static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
>  
>  bool __oom_reap_task_mm(struct mm_struct *mm);
>  
> -extern unsigned long oom_badness(struct task_struct *p,
> +long oom_badness(struct task_struct *p,
>  		unsigned long totalpages);

This is not really necessary.
  
With that being addressed, you can add
Acked-by: Michal Hocko <mhocko@suse.com>

Thanks!
Qian Cai July 10, 2020, 12:42 p.m. UTC | #2 
On Thu, Jul 09, 2020 at 11:53:07AM -0400, Yafang Shao wrote:
> Recently we found an issue on our production environment that when memcg
> oom is triggered the oom killer doesn't chose the process with largest
> resident memory but chose the first scanned process. Note that all
> processes in this memcg have the same oom_score_adj, so the oom killer
> should chose the process with largest resident memory.
> 
> Bellow is part of the oom info, which is enough to analyze this issue.
> [7516987.983223] memory: usage 16777216kB, limit 16777216kB, failcnt 52843037
> [7516987.983224] memory+swap: usage 16777216kB, limit 9007199254740988kB, failcnt 0
> [7516987.983225] kmem: usage 301464kB, limit 9007199254740988kB, failcnt 0
> [...]
> [7516987.983293] [ pid ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
> [7516987.983510] [ 5740]     0  5740      257        1    32768        0          -998 pause
> [7516987.983574] [58804]     0 58804     4594      771    81920        0          -998 entry_point.bas
> [7516987.983577] [58908]     0 58908     7089      689    98304        0          -998 cron
> [7516987.983580] [58910]     0 58910    16235     5576   163840        0          -998 supervisord
> [7516987.983590] [59620]     0 59620    18074     1395   188416        0          -998 sshd
> [7516987.983594] [59622]     0 59622    18680     6679   188416        0          -998 python
> [7516987.983598] [59624]     0 59624  1859266     5161   548864        0          -998 odin-agent
> [7516987.983600] [59625]     0 59625   707223     9248   983040        0          -998 filebeat
> [7516987.983604] [59627]     0 59627   416433    64239   774144        0          -998 odin-log-agent
> [7516987.983607] [59631]     0 59631   180671    15012   385024        0          -998 python3
> [7516987.983612] [61396]     0 61396   791287     3189   352256        0          -998 client
> [7516987.983615] [61641]     0 61641  1844642    29089   946176        0          -998 client
> [7516987.983765] [ 9236]     0  9236     2642      467    53248        0          -998 php_scanner
> [7516987.983911] [42898]     0 42898    15543      838   167936        0          -998 su
> [7516987.983915] [42900]  1000 42900     3673      867    77824        0          -998 exec_script_vr2
> [7516987.983918] [42925]  1000 42925    36475    19033   335872        0          -998 python
> [7516987.983921] [57146]  1000 57146     3673      848    73728        0          -998 exec_script_J2p
> [7516987.983925] [57195]  1000 57195   186359    22958   491520        0          -998 python2
> [7516987.983928] [58376]  1000 58376   275764    14402   290816        0          -998 rosmaster
> [7516987.983931] [58395]  1000 58395   155166     4449   245760        0          -998 rosout
> [7516987.983935] [58406]  1000 58406 18285584  3967322 37101568        0          -998 data_sim
> [7516987.984221] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=3aa16c9482ae3a6f6b78bda68a55d32c87c99b985e0f11331cddf05af6c4d753,mems_allowed=0-1,oom_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184,task_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184/1f246a3eeea8f70bf91141eeaf1805346a666e225f823906485ea0b6c37dfc3d,task=pause,pid=5740,uid=0
> [7516987.984254] Memory cgroup out of memory: Killed process 5740 (pause) total-vm:1028kB, anon-rss:4kB, file-rss:0kB, shmem-rss:0kB
> [7516988.092344] oom_reaper: reaped process 5740 (pause), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> 
> We can find that the first scanned process 5740 (pause) was killed, but its
> rss is only one page. That is because, when we calculate the oom badness in
> oom_badness(), we always ignore the negtive point and convert all of these
> negtive points to 1. Now as oom_score_adj of all the processes in this
> targeted memcg have the same value -998, the points of these processes are
> all negtive value. As a result, the first scanned process will be killed.
> 
> The oom_socre_adj (-998) in this memcg is set by kubelet, because it is a
> a Guaranteed pod, which has higher priority to prevent from being killed by
> system oom.
> 
> To fix this issue, we should make the calculation of oom point more
> accurate. We can achieve it by convert the chosen_point from 'unsigned
> long' to 'long'.
> 
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>

Reverting this commit fixed the crash below while recovering from kenrel OOM,

Reproducer:

# git clone https://github.com/cailca/linux-mm
# cd linux-mm; make
# ./random 5 (just mmap and CoW)

[  261.362982][ T1770] Out of memory and no killable processes...
[  261.391982][ T1770] Kernel panic - not syncing: System is deadlocked on memory
[  261.428413][ T1770] CPU: 44 PID: 1770 Comm: random Not tainted 5.8.0-rc4-next-20200710 #1
[  261.467527][ T1770] Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018
[  261.501318][ T1770] Call Trace:
[  261.516258][ T1770]  dump_stack+0x9d/0xe0
[  261.534637][ T1770]  panic+0x2a1/0x522
[  261.551839][ T1770]  ? __warn_printk+0xd6/0xd6
[  261.572119][ T1770]  ? printk+0x9a/0xc0
[  261.589553][ T1770]  ? dump_header.cold.33+0x166/0x16b
[  261.613525][ T1770]  ? llist_add_batch+0x52/0x90
[  261.635103][ T1770]  out_of_memory.cold.42+0x3b/0x4f
[  261.657861][ T1770]  ? oom_killer_disable+0x210/0x210
[  261.681348][ T1770]  ? mutex_trylock+0x23a/0x2a0
[  261.703208][ T1770]  __alloc_pages_slowpath.constprop.73+0x19e8/0x2420
[  261.733036][ T1770]  ? rcu_read_lock_sched_held+0xaa/0xd0
[  261.757853][ T1770]  ? warn_alloc+0x120/0x120
[  261.777793][ T1770]  ? __alloc_pages_nodemask+0x3b7/0x7d0
[  261.802347][ T1770]  ? lock_downgrade+0x720/0x720
[  261.823934][ T1770]  __alloc_pages_nodemask+0x66b/0x7d0
[  261.847732][ T1770]  ? __alloc_pages_slowpath.constprop.73+0x2420/0x2420
[  261.878316][ T1770]  ? up_read+0x1b2/0x755
[  261.995886][ T1770]  pagecache_get_page+0x15e/0x550
[  262.017892][ T1770]  ? filemap_fault+0x1321/0x1dd0
[  262.039864][ T1770]  filemap_fault+0xafb/0x1dd0
[  262.060633][ T1770]  __xfs_filemap_fault.constprop.6+0x119/0x490
[  262.088029][ T1770]  __do_fault+0xf5/0x550
[  262.106738][ T1770]  ? handle_mm_fault+0x26ec/0x2ef0
[  262.129316][ T1770]  handle_mm_fault+0x21de/0x2ef0
[  262.151211][ T1770]  ? copy_page_range+0x580/0x580
[  262.173193][ T1770]  do_user_addr_fault+0x2af/0x824
[  262.195424][ T1770]  ? trace_hardirqs_off_finish+0x1e7/0x250
[  262.220967][ T1770]  exc_page_fault+0x56/0xa0
[  262.240805][ T1770]  ? asm_exc_page_fault+0x8/0x30
[  262.262230][ T1770]  asm_exc_page_fault+0x1e/0x30
[  262.283642][ T1770] RIP: 0033:0x7f3427adf120
[  262.303060][ T1770] Code: Bad RIP value.
[  262.321132][ T1770] RSP: 002b:00007f34279eaeb8 EFLAGS: 00010206
[  262.348422][ T1770] RAX: 00007f33ee9d5000 RBX: 0000000000000000 RCX: 00007f3427ae28c7
[  262.384779][ T1770] RDX: 00007f310353e000 RSI: 00000003234abf33 RDI: 0000000000000000
[  262.424217][ T1770] RBP: 00007f34279eaef0 R08: 00000000ffffffff R09: 0000000000000000
[  262.463773][ T1770] R10: 0000000000000004 R11: 00007f3427adf120 R12: 00007ffc762430ce
[  262.500186][ T1770] R13: 00007ffc762430cf R14: 0000000000000000 R15: 00007f34279eafc0
[  262.536172][ T1770] Kernel Offset: 0x31600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[  262.588968][ T1770] ---[ end Kernel panic - not syncing: System is deadlocked on memory ]---

More Console outputs prior to the crash,

[  246.610518][ T1778] random invoked oom-killer: gfp_mask=0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), order=0, oom_score_adj=0
[  246.668114][ T1778] CPU: 16 PID: 1778 Comm: random Not tainted 5.8.0-rc4-next-20200710 #1
[  246.706299][ T1778] Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018
[  246.739649][ T1778] Call Trace:
[  246.754012][ T1778]  dump_stack+0x9d/0xe0
[  246.772361][ T1778]  dump_header+0x104/0x830
[  246.792033][ T1778]  ? ___ratelimit+0x1c6/0x400
[  246.812735][ T1778]  oom_kill_process+0x11f/0x330
[  246.834146][ T1778]  out_of_memory+0x63f/0x1320
[  246.856993][ T1778]  ? oom_killer_disable+0x210/0x210
[  246.883648][ T1778]  ? mutex_trylock+0x23a/0x2a0
[  246.907003][ T1778]  __alloc_pages_slowpath.constprop.73+0x19e8/0x2420
[  246.938698][ T1778]  ? __lock_acquire+0xc57/0x4da0
[  246.963601][ T1778]  ? warn_alloc+0x120/0x120
[  246.985262][ T1778]  ? __alloc_pages_nodemask+0x3b7/0x7d0
[  247.011387][ T1778]  ? lock_downgrade+0x720/0x720
[  247.034009][ T1778]  __alloc_pages_nodemask+0x66b/0x7d0
[  247.058147][ T1778]  ? handle_mm_fault+0x1f3/0x2ef0
[  247.080475][ T1778]  ? __alloc_pages_slowpath.constprop.73+0x2420/0x2420
[  247.111122][ T1778]  ? mark_held_locks+0xb0/0x110
[  247.133124][ T1778]  alloc_pages_vma+0xa5/0x4c0
[  247.156360][ T1778]  handle_mm_fault+0x1bdf/0x2ef0
[  247.179379][ T1778]  ? copy_page_range+0x580/0x580
[  247.200926][ T1778]  do_user_addr_fault+0x2af/0x824
[  247.223331][ T1778]  exc_page_fault+0x56/0xa0
[  247.243202][ T1778]  ? asm_exc_page_fault+0x8/0x30
[  247.265347][ T1778]  asm_exc_page_fault+0x1e/0x30
[  247.286788][ T1778] RIP: 0033:0x402cb9
[  247.303935][ T1778] Code: Bad RIP value.
[  247.321938][ T1778] RSP: 002b:00007f1e2c92eec0 EFLAGS: 00010206
[  247.349179][ T1778] RAX: 00007f1a7d0c6000 RBX: 0000000000000000 RCX: 00007f3427ae28c7
[  247.385115][ T1778] RDX: 00007f17e4fd6000 RSI: 00000003234abf33 RDI: 0000000000000000
[  247.420982][ T1778] RBP: 00007f1e2c92eef0 R08: 00000000ffffffff R09: 0000000000000000
[  247.456715][ T1778] R10: 0000000000000022 R11: 0000000000000246 R12: 00007ffc762430ce
[  247.492327][ T1778] R13: 00007ffc762430cf R14: 0000000000000000 R15: 00007f1e2c92efc0
[  247.528232][ T1778] Mem-Info:
[  247.541762][ T1778] active_anon:25261757 inactive_anon:2144151 isolated_anon:0
[  247.541762][ T1778]  active_file:138 inactive_file:81 isolated_file:21
[  247.541762][ T1778]  unevictable:0 dirty:0 writeback:0
[  247.541762][ T1778]  slab_reclaimable:26958 slab_unreclaimable:1049075
[  247.541762][ T1778]  mapped:1189 shmem:2353 pagetables:55339 bounce:0
[  247.541762][ T1778]  free:69553 free_pcp:1530 free_cma:0
[  247.716529][ T1778] Node 0 active_anon:12887656kB inactive_anon:1955060kB active_file:0kB inactive_file:24kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:8kB dirty:0kB writeback:0kB shmem:504kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 13785088kB writeback_tmp:0kB kernel_stack:5024kB all_unreclaimable? no
[  247.848980][ T1778] Node 1 active_anon:29008916kB inactive_anon:3085700kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:364kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 28985344kB writeback_tmp:0kB kernel_stack:4128kB all_unreclaimable? yes
[  247.980966][ T1778] Node 2 active_anon:29063680kB inactive_anon:1757120kB active_file:212kB inactive_file:296kB unevictable:0kB isolated(anon):0kB isolated(file):8kB mapped:4696kB dirty:0kB writeback:0kB shmem:8292kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 29159424kB writeback_tmp:0kB kernel_stack:5568kB all_unreclaimable? no
[  248.117727][ T1778] Node 3 active_anon:30090240kB inactive_anon:1778724kB active_file:268kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:252kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 30033920kB writeback_tmp:0kB kernel_stack:4480kB all_unreclaimable? yes
[  248.254628][ T1778] Node 0 DMA free:15904kB min:16kB low:28kB high:40kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15904kB mlocked:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[  248.378815][ T1778] lowmem_reserve[]: 0 1810 15429 15429
[  248.403362][ T1778] Node 0 DMA32 free:56160kB min:2180kB low:4032kB high:5884kB reserved_highatomic:0KB active_anon:1820964kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:1948156kB managed:1880848kB mlocked:0kB pagetables:8kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[  248.538800][ T1778] lowmem_reserve[]: 0 0 13619 13619
[  248.562446][ T1778] Node 0 Normal free:28424kB min:16404kB low:30348kB high:44292kB reserved_highatomic:12288KB active_anon:11066692kB inactive_anon:1955060kB active_file:0kB inactive_file:8kB unevictable:0kB writepending:0kB present:31457280kB managed:13951408kB mlocked:0kB pagetables:29868kB bounce:0kB free_pcp:828kB local_pcp:4kB free_cma:0kB
[  248.708696][ T1778] lowmem_reserve[]: 0 0 0 0
[  248.728635][ T1778] Node 1 Normal free:56784kB min:38852kB low:71876kB high:104900kB reserved_highatomic:18432KB active_anon:29008916kB inactive_anon:3085700kB active_file:40kB inactive_file:0kB unevictable:0kB writepending:0kB present:33554432kB managed:33027152kB mlocked:0kB pagetables:63652kB bounce:0kB free_pcp:500kB local_pcp:0kB free_cma:0kB
[  248.872458][ T1778] lowmem_reserve[]: 0 0 0 0
[  248.892503][ T1778] Node 2 Normal free:53868kB min:44996kB low:78020kB high:111044kB reserved_highatomic:10240KB active_anon:29071368kB inactive_anon:1757120kB active_file:644kB inactive_file:1132kB unevictable:0kB writepending:0kB present:33554432kB managed:33027156kB mlocked:0kB pagetables:63888kB bounce:0kB free_pcp:16036kB local_pcp:248kB free_cma:0kB
[  249.038452][ T1778] lowmem_reserve[]: 0 0 0 0
[  249.058650][ T1778] Node 3 Normal free:41936kB min:38852kB low:71876kB high:104900kB reserved_highatomic:4096KB active_anon:30090280kB inactive_anon:1778724kB active_file:248kB inactive_file:0kB unevictable:0kB writepending:0kB present:33554432kB managed:33026648kB mlocked:0kB pagetables:63992kB bounce:0kB free_pcp:2160kB local_pcp:508kB free_cma:0kB
[  249.205090][ T1778] lowmem_reserve[]: 0 0 0 0
[  249.226088][ T1778] Node 0 DMA: 2*4kB (U) 1*8kB (U) 1*16kB (U) 0*32kB 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15904kB
[  249.292333][ T1778] Node 0 DMA32: 2*4kB (U) 3*8kB (UM) 4*16kB (UM) 2*32kB (M) 3*64kB (UM) 2*128kB (UM) 5*256kB (UM) 6*512kB (M) 6*1024kB (UM) 0*2048kB 11*4096kB (M) = 56160kB
[  249.365090][ T1778] Node 0 Normal: 117*4kB (UE) 137*8kB (UE) 469*16kB (UME) 179*32kB (UE) 58*64kB (UE) 11*128kB (UE) 0*256kB 4*512kB (M) 6*1024kB (M) 0*2048kB 0*4096kB = 28108kB
[  249.437775][ T1778] Node 1 Normal: 162*4kB (UM) 83*8kB (U) 447*16kB (UME) 52*32kB (UME) 20*64kB (UME) 4*128kB (UME) 3*256kB (ME) 48*512kB (UM) 19*1024kB (M) 0*2048kB 0*4096kB = 56720kB
[  249.513107][ T1778] Node 2 Normal: 594*4kB (UM) 347*8kB (UM) 1014*16kB (UE) 99*32kB (UME) 79*64kB (UME) 144*128kB (UM) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 48032kB
[  249.583100][ T1778] Node 3 Normal: 225*4kB (U) 174*8kB (UM) 814*16kB (UME) 170*32kB (UE) 81*64kB (UE) 63*128kB (UE) 8*256kB (UE) 1*512kB (M) 5*1024kB (UM) 0*2048kB 0*4096kB = 41684kB
[  249.657751][ T1778] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  249.704216][ T1778] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  249.747344][ T1778] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  249.789951][ T1778] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  249.833177][ T1778] Node 2 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  249.876892][ T1778] Node 2 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  249.918701][ T1778] Node 3 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  249.961959][ T1778] Node 3 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  250.003640][ T1778] 830052 total pagecache pages
[  250.024344][ T1778] 827547 pages in swap cache
[  250.044627][ T1778] Swap cache stats: add 1048489, delete 221144, find 135/169
[  250.077908][ T1778] Free swap  = 0kB
[  250.094176][ T1778] Total swap = 4194300kB
[  250.112858][ T1778] 33521181 pages RAM
[  250.130761][ T1778] 0 pages HighMem/MovableOnly
[  250.152483][ T1778] 4788902 pages reserved
[  250.171254][ T1778] 0 pages hwpoisoned
[  250.189104][ T1778] Tasks state (memory values in pages):
[  250.216265][ T1778] [  pid  ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
[  250.260075][ T1778] [    893]     0   893    27572     1402   249856        0             0 systemd-journal
[  250.305110][ T1778] [    928]     0   928    26661      567   229376        0         -1000 systemd-udevd
[  250.349061][ T1778] [   1147]     0  1147    31227      173   143360       31             0 irqbalance
[  250.392400][ T1778] [   1155]    81  1155    18672      144   167936       53          -900 dbus-daemon
[  250.435855][ T1778] [   1157]   998  1157   508379     1349   385024      902             0 polkitd
[  250.477995][ T1778] [   1158]     0  1158    53104      391   421888      101             0 sssd
[  250.518371][ T1778] [   1159]     0  1159    97608      478   368640      129             0 NetworkManager
[  250.562804][ T1778] [   1162]   994  1162    95357      173   229376       35             0 rngd
[  250.604826][ T1778] [   1164]   995  1164     7366       48    94208       19             0 chronyd
[  250.648036][ T1778] [   1169]     0  1169     7337      374    86016      742             0 ksmtuned
[  250.690923][ T1778] [   1200]     0  1200    23773      130   204800       98         -1000 sshd
[  250.736317][ T1778] [   1203]     0  1203   106493     3161   434176     1244             0 tuned
[  250.777240][ T1778] [   1219]     0  1219    10394      100   106496       32             0 rhsmcertd
[  250.819134][ T1778] [   1238]     0  1238    54766      421   438272      216             0 sssd_be
[  250.861075][ T1778] [   1246]     0  1246    55309      406   462848        0             0 sssd_nss
[  250.903953][ T1778] [   1255]     0  1255    24020      219   208896       29             0 systemd-logind
[  250.947724][ T1778] [   1263]     0  1263     3918       25    77824        8             0 agetty
[  250.987890][ T1778] [   1272]     0  1272    23433      337   225280       17             0 systemd
[  251.029612][ T1778] [   1285]     0  1285    37329      427   299008      259             0 (sd-pam)
[  251.072439][ T1778] [   1517]     0  1517    54398      193   184320       46             0 rsyslogd
[  251.116327][ T1778] [   1527]     0  1527     9024      196   102400       25             0 crond
[  251.158985][ T1778] [   1531]     0  1531    63396      180   118784       24         -1000 restraintd
[  251.204944][ T1778] [   1541]     0  1541     6312       71    81920       17         -1000 10_bash_login
[  251.254455][ T1778] [   1568]     0  1568     2425        6    61440       49             0 make
[  251.296110][ T1778] [   1572]     0  1572     6312       92    81920       10             0 runtest.sh
[  251.340690][ T1778] [   1658]     0  1658    38227      293   299008       19             0 sshd
[  251.382404][ T1778] [   1674]     0  1674    38227      264   294912       51             0 sshd
[  251.424319][ T1778] [   1686]     0  1686     6346       45    94208      105             0 bash
[  251.466076][ T1778] [   1768]     0  1768     1639        0    61440       28             0 random
[  251.508756][ T1778] [   1769]     0  1769 32924969 26568800 221474816  1042033             0 random
[  251.551728][ T1778] [   1793]     0  1793     1821       25    61440        0             0 sleep
[  251.593685][ T1778] [   1798]     0  1798     1821       15    57344        0             0 sleep
[  251.635656][ T1778] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0-3,global_oom,task_memcg=/system.slice/dbus.service,task=dbus-daemon,pid=1155,uid=81
[  251.716666][ T1778] Out of memory: Killed process 1155 (dbus-daemon) total-vm:74688kB, anon-rss:572kB, file-rss:4kB, shmem-rss:0kB, UID:81 pgtables:164kB oom_score_adj:-900
[  251.795110][  T353] oom_reaper: reaped process 1155 (dbus-daemon), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
[  251.877615][ T1793] sleep (1793) used greatest stack depth: 18696 bytes left
[  256.237437][ T1770] random invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
[  256.289783][ T1770] CPU: 44 PID: 1770 Comm: random Not tainted 5.8.0-rc4-next-20200710 #1
[  256.329061][ T1770] Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018
[  256.363958][ T1770] Call Trace:
[  256.378672][ T1770]  dump_stack+0x9d/0xe0
[  256.397817][ T1770]  dump_header+0x104/0x830
[  256.418135][ T1770]  ? oom_evaluate_task+0x2fb/0x550
[  256.441580][ T1770]  out_of_memory+0xf17/0x1320
[  256.463209][ T1770]  ? oom_killer_disable+0x210/0x210
[  256.486890][ T1770]  ? mutex_trylock+0x23a/0x2a0
[  256.509086][ T1770]  __alloc_pages_slowpath.constprop.73+0x19e8/0x2420
[  256.539952][ T1770]  ? rcu_read_lock_sched_held+0xaa/0xd0
[  256.565885][ T1770]  ? warn_alloc+0x120/0x120
[  256.586540][ T1770]  ? __alloc_pages_nodemask+0x3b7/0x7d0
[  256.611648][ T1770]  ? lock_downgrade+0x720/0x720
[  256.633613][ T1770]  __alloc_pages_nodemask+0x66b/0x7d0
[  256.658355][ T1770]  ? __alloc_pages_slowpath.constprop.73+0x2420/0x2420
[  256.690335][ T1770]  ? up_read+0x1b2/0x755
[  256.709484][ T1770]  pagecache_get_page+0x15e/0x550
[  256.732772][ T1770]  ? filemap_fault+0x1321/0x1dd0
[  256.755246][ T1770]  filemap_fault+0xafb/0x1dd0
[  256.778313][ T1770]  __xfs_filemap_fault.constprop.6+0x119/0x490
[  256.808802][ T1770]  __do_fault+0xf5/0x550
[  256.828058][ T1770]  ? handle_mm_fault+0x26ec/0x2ef0
[  256.851543][ T1770]  handle_mm_fault+0x21de/0x2ef0
[  256.874265][ T1770]  ? copy_page_range+0x580/0x580
[  256.897346][ T1770]  do_user_addr_fault+0x2af/0x824
[  256.919942][ T1770]  ? trace_hardirqs_off_finish+0x1e7/0x250
[  256.947004][ T1770]  exc_page_fault+0x56/0xa0
[  256.967920][ T1770]  ? asm_exc_page_fault+0x8/0x30
[  256.991703][ T1770]  asm_exc_page_fault+0x1e/0x30
[  257.013863][ T1770] RIP: 0033:0x7f3427adf120
[  257.034132][ T1770] Code: Bad RIP value.
[  257.053045][ T1770] RSP: 002b:00007f34279eaeb8 EFLAGS: 00010206
[  257.081173][ T1770] RAX: 00007f33ee9d5000 RBX: 0000000000000000 RCX: 00007f3427ae28c7
[  257.118606][ T1770] RDX: 00007f310353e000 RSI: 00000003234abf33 RDI: 0000000000000000
[  257.155693][ T1770] RBP: 00007f34279eaef0 R08: 00000000ffffffff R09: 0000000000000000
[  257.192771][ T1770] R10: 0000000000000004 R11: 00007f3427adf120 R12: 00007ffc762430ce
[  257.229803][ T1770] R13: 00007ffc762430cf R14: 0000000000000000 R15: 00007f34279eafc0
[  257.267345][ T1770] Mem-Info:
[  257.282676][ T1770] active_anon:25449780 inactive_anon:1965016 isolated_anon:0
[  257.282676][ T1770]  active_file:65 inactive_file:0 isolated_file:0
[  257.282676][ T1770]  unevictable:0 dirty:0 writeback:0
[  257.282676][ T1770]  slab_reclaimable:27023 slab_unreclaimable:1048444
[  257.282676][ T1770]  mapped:392 shmem:2334 pagetables:55543 bounce:0
[  257.282676][ T1770]  free:62065 free_pcp:554 free_cma:0
[  257.461086][ T1770] Node 0 active_anon:12935916kB inactive_anon:1909368kB active_file:36kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:12kB dirty:0kB writeback:0kB shmem:504kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 13744128kB writeback_tmp:0kB kernel_stack:5056kB all_unreclaimable? yes
[  257.596604][ T1770] Node 1 active_anon:29673204kB inactive_anon:2420336kB active_file:0kB inactive_file:16kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:352kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 28454912kB writeback_tmp:0kB kernel_stack:4128kB all_unreclaimable? yes
[  257.729603][ T1770] Node 2 active_anon:29105592kB inactive_anon:1743448kB active_file:80kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:1664kB dirty:0kB writeback:0kB shmem:8244kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 28469248kB writeback_tmp:0kB kernel_stack:5568kB all_unreclaimable? yes
[  257.869589][ T1770] Node 3 active_anon:30084408kB inactive_anon:1786912kB active_file:172kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:236kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 29853696kB writeback_tmp:0kB kernel_stack:4448kB all_unreclaimable? yes
[  258.002724][ T1770] Node 0 DMA free:15904kB min:16kB low:28kB high:40kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15904kB mlocked:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[  258.125796][ T1770] lowmem_reserve[]: 0 1810 15429 15429
[  258.150081][ T1770] Node 0 DMA32 free:56160kB min:2180kB low:4032kB high:5884kB reserved_highatomic:0KB active_anon:1820964kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:1948156kB managed:1880848kB mlocked:0kB pagetables:8kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[  258.282380][ T1770] lowmem_reserve[]: 0 0 13619 13619
[  258.306345][ T1770] Node 0 Normal free:27708kB min:16404kB low:30348kB high:44292kB reserved_highatomic:12288KB active_anon:11114952kB inactive_anon:1909368kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:31457280kB managed:13951408kB mlocked:0kB pagetables:29840kB bounce:0kB free_pcp:1100kB local_pcp:0kB free_cma:0kB
[  258.451411][ T1770] lowmem_reserve[]: 0 0 0 0
[  258.471323][ T1770] Node 1 Normal free:56716kB min:38852kB low:71876kB high:104900kB reserved_highatomic:18432KB active_anon:29673208kB inactive_anon:2420336kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:33554432kB managed:33027152kB mlocked:0kB pagetables:63984kB bounce:0kB free_pcp:724kB local_pcp:0kB free_cma:0kB
[  258.611278][ T1770] lowmem_reserve[]: 0 0 0 0
[  258.631152][ T1770] Node 2 Normal free:48984kB min:38852kB low:71876kB high:104900kB reserved_highatomic:10240KB active_anon:29105592kB inactive_anon:1743448kB active_file:108kB inactive_file:0kB unevictable:0kB writepending:0kB present:33554432kB managed:33027156kB mlocked:0kB pagetables:64248kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[  258.771172][ T1770] lowmem_reserve[]: 0 0 0 0
[  258.791140][ T1770] Node 3 Normal free:42624kB min:38852kB low:71876kB high:104900kB reserved_highatomic:4096KB active_anon:30084408kB inactive_anon:1786912kB active_file:220kB inactive_file:0kB unevictable:0kB writepending:0kB present:33554432kB managed:33026648kB mlocked:0kB pagetables:64092kB bounce:0kB free_pcp:356kB local_pcp:40kB free_cma:0kB
[  258.939974][ T1770] lowmem_reserve[]: 0 0 0 0
[  258.959555][ T1770] Node 0 DMA: 2*4kB (U) 1*8kB (U) 1*16kB (U) 0*32kB 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15904kB
[  259.026918][ T1770] Node 0 DMA32: 2*4kB (U) 3*8kB (UM) 4*16kB (UM) 2*32kB (M) 3*64kB (UM) 2*128kB (UM) 5*256kB (UM) 6*512kB (M) 6*1024kB (UM) 0*2048kB 11*4096kB (M) = 56160kB
[  259.099706][ T1770] Node 0 Normal: 69*4kB (UME) 142*8kB (UME) 472*16kB (UME) 203*32kB (UME) 68*64kB (UME) 14*128kB (UME) 0*256kB 0*512kB 6*1024kB (M) 0*2048kB 0*4096kB = 27748kB
[  259.175171][ T1770] Node 1 Normal: 105*4kB (UME) 77*8kB (UME) 438*16kB (UME) 28*32kB (UME) 12*64kB (UME) 3*128kB (UE) 2*256kB (E) 20*512kB (UM) 35*1024kB (M) 0*2048kB 0*4096kB = 56684kB
[  259.252959][ T1770] Node 2 Normal: 526*4kB (UM) 406*8kB (UM) 1107*16kB (UME) 156*32kB (UME) 159*64kB (UME) 82*128kB (UM) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 48984kB
[  259.326006][ T1770] Node 3 Normal: 282*4kB (UM) 199*8kB (UM) 828*16kB (UME) 167*32kB (UME) 83*64kB (UME) 75*128kB (UME) 9*256kB (UME) 0*512kB 4*1024kB (UM) 0*2048kB 0*4096kB = 42624kB
[  259.406007][ T1770] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  259.452447][ T1770] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  259.496823][ T1770] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  259.539971][ T1770] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  259.581942][ T1770] Node 2 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  259.625200][ T1770] Node 2 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  259.666879][ T1770] Node 3 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[  259.709798][ T1770] Node 3 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  259.751068][ T1770] 742508 total pagecache pages
[  259.772116][ T1770] 740154 pages in swap cache
[  259.792405][ T1770] Swap cache stats: add 1048884, delete 308889, find 186/397
[  259.825548][ T1770] Free swap  = 0kB
[  259.843259][ T1770] Total swap = 4194300kB
[  259.863815][ T1770] 33521181 pages RAM
[  259.882683][ T1770] 0 pages HighMem/MovableOnly
[  259.904128][ T1770] 4788902 pages reserved
[  259.922912][ T1770] 0 pages hwpoisoned
[  259.940059][ T1770] Tasks state (memory values in pages):
[  259.964779][ T1770] [  pid  ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
[  260.007423][ T1770] [    893]     0   893    27572      680   249856        0             0 systemd-journal
[  260.052192][ T1770] [    928]     0   928    26661      555   229376       12         -1000 systemd-udevd
[  260.096152][ T1770] [   1147]     0  1147    31227      169   143360       35             0 irqbalance
[  260.138753][ T1770] [   1157]   998  1157   508379     1412   385024      867             0 polkitd
[  260.181125][ T1770] [   1158]     0  1158    53104      384   421888      108             0 sssd
[  260.222429][ T1770] [   1159]     0  1159    97608      531   368640      106             0 NetworkManager
[  260.267509][ T1770] [   1162]   994  1162    95357      172   229376       36             0 rngd
[  260.308103][ T1770] [   1164]   995  1164     7366       45    94208       22             0 chronyd
[  260.350334][ T1770] [   1169]     0  1169     7337      371    86016      745             0 ksmtuned
[  260.395957][ T1770] [   1200]     0  1200    23773      128   204800      100         -1000 sshd
[  260.436408][ T1770] [   1203]     0  1203   106493     3196   434176     1214             0 tuned
[  260.476988][ T1770] [   1219]     0  1219    10394       99   106496       33             0 rhsmcertd
[  260.519120][ T1770] [   1238]     0  1238    54766      420   438272      217             0 sssd_be
[  260.560519][ T1770] [   1246]     0  1246    55309      406   462848        0             0 sssd_nss
[  260.602315][ T1770] [   1255]     0  1255    24020      226   208896       23             0 systemd-logind
[  260.646396][ T1770] [   1263]     0  1263     3918       23    77824       10             0 agetty
[  260.687288][ T1770] [   1272]     0  1272    23433      342   225280       16             0 systemd
[  260.728686][ T1770] [   1285]     0  1285    37329      420   299008      266             0 (sd-pam)
[  260.770420][ T1770] [   1517]     0  1517    54398      166   184320       46             0 rsyslogd
[  260.812273][ T1770] [   1527]     0  1527     9024      190   102400       31             0 crond
[  260.853747][ T1770] [   1531]     0  1531    63396      179   118784       25         -1000 restraintd
[  260.901574][ T1770] [   1541]     0  1541     6312       71    81920       17         -1000 10_bash_login
[  260.945269][ T1770] [   1568]     0  1568     2425        6    61440       49             0 make
[  260.985486][ T1770] [   1572]     0  1572     6312       89    81920       12             0 runtest.sh
[  261.028161][ T1770] [   1658]     0  1658    38227      291   299008       21             0 sshd
[  261.068328][ T1770] [   1674]     0  1674    38227      262   294912       53             0 sshd
[  261.108488][ T1770] [   1686]     0  1686     6346       45    94208      105             0 bash
[  261.148602][ T1770] [   1768]     0  1768     1639        0    61440       28             0 random
[  261.189874][ T1770] [   1769]     0  1769 32924969 26661064 222212096  1042153             0 random
[  261.233064][ T1770] [   1798]     0  1798     1821       15    57344        0             0 sleep
[  261.274004][ T1770] [   1799]     0  1799    15922       63   143360        0             0 systemd-cgroups
[  261.320765][ T1770] [   1801]     0  1801     1090       23    53248        0             0 sleep
[  261.362982][ T1770] Out of memory and no killable processes...
[  261.391982][ T1770] Kernel panic - not syncing: System is deadlocked on memory
[  261.428413][ T1770] CPU: 44 PID: 1770 Comm: random Not tainted 5.8.0-rc4-next-20200710 #1
[  261.467527][ T1770] Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018
[  261.501318][ T1770] Call Trace:
[  261.516258][ T1770]  dump_stack+0x9d/0xe0
[  261.534637][ T1770]  panic+0x2a1/0x522
[  261.551839][ T1770]  ? __warn_printk+0xd6/0xd6
[  261.572119][ T1770]  ? printk+0x9a/0xc0
[  261.589553][ T1770]  ? dump_header.cold.33+0x166/0x16b
[  261.613525][ T1770]  ? llist_add_batch+0x52/0x90
[  261.635103][ T1770]  out_of_memory.cold.42+0x3b/0x4f
[  261.657861][ T1770]  ? oom_killer_disable+0x210/0x210
[  261.681348][ T1770]  ? mutex_trylock+0x23a/0x2a0
[  261.703208][ T1770]  __alloc_pages_slowpath.constprop.73+0x19e8/0x2420
[  261.733036][ T1770]  ? rcu_read_lock_sched_held+0xaa/0xd0
[  261.757853][ T1770]  ? warn_alloc+0x120/0x120
[  261.777793][ T1770]  ? __alloc_pages_nodemask+0x3b7/0x7d0
[  261.802347][ T1770]  ? lock_downgrade+0x720/0x720
[  261.823934][ T1770]  __alloc_pages_nodemask+0x66b/0x7d0
[  261.847732][ T1770]  ? __alloc_pages_slowpath.constprop.73+0x2420/0x2420
[  261.878316][ T1770]  ? up_read+0x1b2/0x755
[  261.995886][ T1770]  pagecache_get_page+0x15e/0x550
[  262.017892][ T1770]  ? filemap_fault+0x1321/0x1dd0
[  262.039864][ T1770]  filemap_fault+0xafb/0x1dd0
[  262.060633][ T1770]  __xfs_filemap_fault.constprop.6+0x119/0x490
[  262.088029][ T1770]  __do_fault+0xf5/0x550
[  262.106738][ T1770]  ? handle_mm_fault+0x26ec/0x2ef0
[  262.129316][ T1770]  handle_mm_fault+0x21de/0x2ef0
[  262.151211][ T1770]  ? copy_page_range+0x580/0x580
[  262.173193][ T1770]  do_user_addr_fault+0x2af/0x824
[  262.195424][ T1770]  ? trace_hardirqs_off_finish+0x1e7/0x250
[  262.220967][ T1770]  exc_page_fault+0x56/0xa0
[  262.240805][ T1770]  ? asm_exc_page_fault+0x8/0x30
[  262.262230][ T1770]  asm_exc_page_fault+0x1e/0x30
[  262.283642][ T1770] RIP: 0033:0x7f3427adf120
[  262.303060][ T1770] Code: Bad RIP value.
[  262.321132][ T1770] RSP: 002b:00007f34279eaeb8 EFLAGS: 00010206
[  262.348422][ T1770] RAX: 00007f33ee9d5000 RBX: 0000000000000000 RCX: 00007f3427ae28c7
[  262.384779][ T1770] RDX: 00007f310353e000 RSI: 00000003234abf33 RDI: 0000000000000000
[  262.424217][ T1770] RBP: 00007f34279eaef0 R08: 00000000ffffffff R09: 0000000000000000
[  262.463773][ T1770] R10: 0000000000000004 R11: 00007f3427adf120 R12: 00007ffc762430ce
[  262.500186][ T1770] R13: 00007ffc762430cf R14: 0000000000000000 R15: 00007f34279eafc0
[  262.536172][ T1770] Kernel Offset: 0x31600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[  262.588968][ T1770] ---[ end Kernel panic - not syncing: System is deadlocked on memory ]---

> ---
>  drivers/tty/sysrq.c |  1 +
>  fs/proc/base.c      |  7 ++++++-
>  include/linux/oom.h |  4 ++--
>  mm/memcontrol.c     |  1 +
>  mm/oom_kill.c       | 19 ++++++++-----------
>  mm/page_alloc.c     |  1 +
>  6 files changed, 19 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
> index 7c95afa9..e83fd46 100644
> --- a/drivers/tty/sysrq.c
> +++ b/drivers/tty/sysrq.c
> @@ -382,6 +382,7 @@ static void moom_callback(struct work_struct *ignored)
>  		.memcg = NULL,
>  		.gfp_mask = gfp_mask,
>  		.order = -1,
> +		.chosen_points = LONG_MIN,
>  	};
>  
>  	mutex_lock(&oom_lock);
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index d86c0af..bf16406 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -551,8 +551,13 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
>  {
>  	unsigned long totalpages = totalram_pages() + total_swap_pages;
>  	unsigned long points = 0;
> +	long badness;
>  
> -	points = oom_badness(task, totalpages) * 1000 / totalpages;
> +	badness = oom_badness(task, totalpages);
> +	if (badness != LONG_MIN) {
> +		/* Let's keep the range of points as [0, 2000]. */
> +		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
> +	}
>  	seq_printf(m, "%lu\n", points);
>  
>  	return 0;
> diff --git a/include/linux/oom.h b/include/linux/oom.h
> index c696c26..f022f58 100644
> --- a/include/linux/oom.h
> +++ b/include/linux/oom.h
> @@ -48,7 +48,7 @@ struct oom_control {
>  	/* Used by oom implementation, do not set */
>  	unsigned long totalpages;
>  	struct task_struct *chosen;
> -	unsigned long chosen_points;
> +	long chosen_points;
>  
>  	/* Used to print the constraint info. */
>  	enum oom_constraint constraint;
> @@ -107,7 +107,7 @@ static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
>  
>  bool __oom_reap_task_mm(struct mm_struct *mm);
>  
> -extern unsigned long oom_badness(struct task_struct *p,
> +long oom_badness(struct task_struct *p,
>  		unsigned long totalpages);
>  
>  extern bool out_of_memory(struct oom_control *oc);
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 1962232..df73b30 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1559,6 +1559,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
>  		.memcg = memcg,
>  		.gfp_mask = gfp_mask,
>  		.order = order,
> +		.chosen_points = LONG_MIN,
>  	};
>  	bool ret;
>  
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 6e94962..2dd5a90 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -196,17 +196,17 @@ static bool is_dump_unreclaim_slabs(void)
>   * predictable as possible.  The goal is to return the highest value for the
>   * task consuming the most memory to avoid subsequent oom failures.
>   */
> -unsigned long oom_badness(struct task_struct *p, unsigned long totalpages)
> +long oom_badness(struct task_struct *p, unsigned long totalpages)
>  {
>  	long points;
>  	long adj;
>  
>  	if (oom_unkillable_task(p))
> -		return 0;
> +		return LONG_MIN;
>  
>  	p = find_lock_task_mm(p);
>  	if (!p)
> -		return 0;
> +		return LONG_MIN;
>  
>  	/*
>  	 * Do not even consider tasks which are explicitly marked oom
> @@ -218,7 +218,7 @@ unsigned long oom_badness(struct task_struct *p, unsigned long totalpages)
>  			test_bit(MMF_OOM_SKIP, &p->mm->flags) ||
>  			in_vfork(p)) {
>  		task_unlock(p);
> -		return 0;
> +		return LONG_MIN;
>  	}
>  
>  	/*
> @@ -233,11 +233,7 @@ unsigned long oom_badness(struct task_struct *p, unsigned long totalpages)
>  	adj *= totalpages / 1000;
>  	points += adj;
>  
> -	/*
> -	 * Never return 0 for an eligible task regardless of the root bonus and
> -	 * oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here).
> -	 */
> -	return points > 0 ? points : 1;
> +	return points;
>  }
>  
>  static const char * const oom_constraint_text[] = {
> @@ -336,12 +332,12 @@ static int oom_evaluate_task(struct task_struct *task, void *arg)
>  	 * killed first if it triggers an oom, then select it.
>  	 */
>  	if (oom_task_origin(task)) {
> -		points = ULONG_MAX;
> +		points = LONG_MAX;
>  		goto select;
>  	}
>  
>  	points = oom_badness(task, oc->totalpages);
> -	if (!points || points < oc->chosen_points)
> +	if (points == LONG_MIN || points < oc->chosen_points)
>  		goto next;
>  
>  select:
> @@ -1128,6 +1124,7 @@ void pagefault_out_of_memory(void)
>  		.memcg = NULL,
>  		.gfp_mask = 0,
>  		.order = 0,
> +		.chosen_points = LONG_MIN,
>  	};
>  
>  	if (mem_cgroup_oom_synchronize(true))
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e028b87c..8eec9d65 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3896,6 +3896,7 @@ void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
>  		.memcg = NULL,
>  		.gfp_mask = gfp_mask,
>  		.order = order,
> +		.chosen_points = LONG_MIN,
>  	};
>  	struct page *page;
>  
> -- 
> 1.8.3.1
> 
>
Michal Hocko July 10, 2020, 12:58 p.m. UTC | #3 
On Fri 10-07-20 08:42:53, Qian Cai wrote:
> On Thu, Jul 09, 2020 at 11:53:07AM -0400, Yafang Shao wrote:
> > Recently we found an issue on our production environment that when memcg
> > oom is triggered the oom killer doesn't chose the process with largest
> > resident memory but chose the first scanned process. Note that all
> > processes in this memcg have the same oom_score_adj, so the oom killer
> > should chose the process with largest resident memory.
> > 
> > Bellow is part of the oom info, which is enough to analyze this issue.
> > [7516987.983223] memory: usage 16777216kB, limit 16777216kB, failcnt 52843037
> > [7516987.983224] memory+swap: usage 16777216kB, limit 9007199254740988kB, failcnt 0
> > [7516987.983225] kmem: usage 301464kB, limit 9007199254740988kB, failcnt 0
> > [...]
> > [7516987.983293] [ pid ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
> > [7516987.983510] [ 5740]     0  5740      257        1    32768        0          -998 pause
> > [7516987.983574] [58804]     0 58804     4594      771    81920        0          -998 entry_point.bas
> > [7516987.983577] [58908]     0 58908     7089      689    98304        0          -998 cron
> > [7516987.983580] [58910]     0 58910    16235     5576   163840        0          -998 supervisord
> > [7516987.983590] [59620]     0 59620    18074     1395   188416        0          -998 sshd
> > [7516987.983594] [59622]     0 59622    18680     6679   188416        0          -998 python
> > [7516987.983598] [59624]     0 59624  1859266     5161   548864        0          -998 odin-agent
> > [7516987.983600] [59625]     0 59625   707223     9248   983040        0          -998 filebeat
> > [7516987.983604] [59627]     0 59627   416433    64239   774144        0          -998 odin-log-agent
> > [7516987.983607] [59631]     0 59631   180671    15012   385024        0          -998 python3
> > [7516987.983612] [61396]     0 61396   791287     3189   352256        0          -998 client
> > [7516987.983615] [61641]     0 61641  1844642    29089   946176        0          -998 client
> > [7516987.983765] [ 9236]     0  9236     2642      467    53248        0          -998 php_scanner
> > [7516987.983911] [42898]     0 42898    15543      838   167936        0          -998 su
> > [7516987.983915] [42900]  1000 42900     3673      867    77824        0          -998 exec_script_vr2
> > [7516987.983918] [42925]  1000 42925    36475    19033   335872        0          -998 python
> > [7516987.983921] [57146]  1000 57146     3673      848    73728        0          -998 exec_script_J2p
> > [7516987.983925] [57195]  1000 57195   186359    22958   491520        0          -998 python2
> > [7516987.983928] [58376]  1000 58376   275764    14402   290816        0          -998 rosmaster
> > [7516987.983931] [58395]  1000 58395   155166     4449   245760        0          -998 rosout
> > [7516987.983935] [58406]  1000 58406 18285584  3967322 37101568        0          -998 data_sim
> > [7516987.984221] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=3aa16c9482ae3a6f6b78bda68a55d32c87c99b985e0f11331cddf05af6c4d753,mems_allowed=0-1,oom_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184,task_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184/1f246a3eeea8f70bf91141eeaf1805346a666e225f823906485ea0b6c37dfc3d,task=pause,pid=5740,uid=0
> > [7516987.984254] Memory cgroup out of memory: Killed process 5740 (pause) total-vm:1028kB, anon-rss:4kB, file-rss:0kB, shmem-rss:0kB
> > [7516988.092344] oom_reaper: reaped process 5740 (pause), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> > 
> > We can find that the first scanned process 5740 (pause) was killed, but its
> > rss is only one page. That is because, when we calculate the oom badness in
> > oom_badness(), we always ignore the negtive point and convert all of these
> > negtive points to 1. Now as oom_score_adj of all the processes in this
> > targeted memcg have the same value -998, the points of these processes are
> > all negtive value. As a result, the first scanned process will be killed.
> > 
> > The oom_socre_adj (-998) in this memcg is set by kubelet, because it is a
> > a Guaranteed pod, which has higher priority to prevent from being killed by
> > system oom.
> > 
> > To fix this issue, we should make the calculation of oom point more
> > accurate. We can achieve it by convert the chosen_point from 'unsigned
> > long' to 'long'.
> > 
> > Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> 
> Reverting this commit fixed the crash below while recovering from kenrel OOM,

I suspect that the previous version of the patch has been tested (in
Linux next). Does this version exhibit the same problem?

I will have a closer look. Is the full dmesg available somewhere?
Michal Hocko July 10, 2020, 1:07 p.m. UTC | #4 
On Fri 10-07-20 14:58:54, Michal Hocko wrote:
[...]
> I will have a closer look. Is the full dmesg available somewhere?

Ups, I have missed this:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 2dd5a90f2f81..7f01835862f4 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -306,7 +306,7 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
 static int oom_evaluate_task(struct task_struct *task, void *arg)
 {
 	struct oom_control *oc = arg;
-	unsigned long points;
+	long points;
 
 	if (oom_unkillable_task(task))
 		goto next;

Does it help?
Yafang Shao July 10, 2020, 2:04 p.m. UTC | #5 
On Fri, Jul 10, 2020 at 9:07 PM Michal Hocko <mhocko@kernel.org> wrote:
>
> On Fri 10-07-20 14:58:54, Michal Hocko wrote:
> [...]
> > I will have a closer look. Is the full dmesg available somewhere?
>
> Ups, I have missed this:
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 2dd5a90f2f81..7f01835862f4 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -306,7 +306,7 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
>  static int oom_evaluate_task(struct task_struct *task, void *arg)
>  {
>         struct oom_control *oc = arg;
> -       unsigned long points;
> +       long points;
>
>         if (oom_unkillable_task(task))
>                 goto next;
>
> Does it help?
> --

Thanks Michal. This should be the fix.
I did it in our in-house kernel, but when I posted it to upstream I
missed it. That's my fault.
Yafang Shao July 10, 2020, 2:10 p.m. UTC | #6 
On Fri, Jul 10, 2020 at 8:10 PM Michal Hocko <mhocko@kernel.org> wrote:
>
> On Thu 09-07-20 11:53:07, Yafang Shao wrote:
> > Recently we found an issue on our production environment that when memcg
> > oom is triggered the oom killer doesn't chose the process with largest
> > resident memory but chose the first scanned process. Note that all
> > processes in this memcg have the same oom_score_adj, so the oom killer
> > should chose the process with largest resident memory.
> >
> > Bellow is part of the oom info, which is enough to analyze this issue.
> > [7516987.983223] memory: usage 16777216kB, limit 16777216kB, failcnt 52843037
> > [7516987.983224] memory+swap: usage 16777216kB, limit 9007199254740988kB, failcnt 0
> > [7516987.983225] kmem: usage 301464kB, limit 9007199254740988kB, failcnt 0
> > [...]
> > [7516987.983293] [ pid ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
> > [7516987.983510] [ 5740]     0  5740      257        1    32768        0          -998 pause
> > [7516987.983574] [58804]     0 58804     4594      771    81920        0          -998 entry_point.bas
> > [7516987.983577] [58908]     0 58908     7089      689    98304        0          -998 cron
> > [7516987.983580] [58910]     0 58910    16235     5576   163840        0          -998 supervisord
> > [7516987.983590] [59620]     0 59620    18074     1395   188416        0          -998 sshd
> > [7516987.983594] [59622]     0 59622    18680     6679   188416        0          -998 python
> > [7516987.983598] [59624]     0 59624  1859266     5161   548864        0          -998 odin-agent
> > [7516987.983600] [59625]     0 59625   707223     9248   983040        0          -998 filebeat
> > [7516987.983604] [59627]     0 59627   416433    64239   774144        0          -998 odin-log-agent
> > [7516987.983607] [59631]     0 59631   180671    15012   385024        0          -998 python3
> > [7516987.983612] [61396]     0 61396   791287     3189   352256        0          -998 client
> > [7516987.983615] [61641]     0 61641  1844642    29089   946176        0          -998 client
> > [7516987.983765] [ 9236]     0  9236     2642      467    53248        0          -998 php_scanner
> > [7516987.983911] [42898]     0 42898    15543      838   167936        0          -998 su
> > [7516987.983915] [42900]  1000 42900     3673      867    77824        0          -998 exec_script_vr2
> > [7516987.983918] [42925]  1000 42925    36475    19033   335872        0          -998 python
> > [7516987.983921] [57146]  1000 57146     3673      848    73728        0          -998 exec_script_J2p
> > [7516987.983925] [57195]  1000 57195   186359    22958   491520        0          -998 python2
> > [7516987.983928] [58376]  1000 58376   275764    14402   290816        0          -998 rosmaster
> > [7516987.983931] [58395]  1000 58395   155166     4449   245760        0          -998 rosout
> > [7516987.983935] [58406]  1000 58406 18285584  3967322 37101568        0          -998 data_sim
> > [7516987.984221] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=3aa16c9482ae3a6f6b78bda68a55d32c87c99b985e0f11331cddf05af6c4d753,mems_allowed=0-1,oom_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184,task_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184/1f246a3eeea8f70bf91141eeaf1805346a666e225f823906485ea0b6c37dfc3d,task=pause,pid=5740,uid=0
> > [7516987.984254] Memory cgroup out of memory: Killed process 5740 (pause) total-vm:1028kB, anon-rss:4kB, file-rss:0kB, shmem-rss:0kB
> > [7516988.092344] oom_reaper: reaped process 5740 (pause), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> >
> > We can find that the first scanned process 5740 (pause) was killed, but its
> > rss is only one page. That is because, when we calculate the oom badness in
> > oom_badness(), we always ignore the negtive point and convert all of these
> > negtive points to 1. Now as oom_score_adj of all the processes in this
> > targeted memcg have the same value -998, the points of these processes are
> > all negtive value. As a result, the first scanned process will be killed.
> >
> > The oom_socre_adj (-998) in this memcg is set by kubelet, because it is a
> > a Guaranteed pod, which has higher priority to prevent from being killed by
> > system oom.
> >
> > To fix this issue, we should make the calculation of oom point more
> > accurate. We can achieve it by convert the chosen_point from 'unsigned
> > long' to 'long'.
> >
> > Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> > ---
> >  drivers/tty/sysrq.c |  1 +
> >  fs/proc/base.c      |  7 ++++++-
> >  include/linux/oom.h |  4 ++--
> >  mm/memcontrol.c     |  1 +
> >  mm/oom_kill.c       | 19 ++++++++-----------
> >  mm/page_alloc.c     |  1 +
> >  6 files changed, 19 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
> > index 7c95afa9..e83fd46 100644
> > --- a/drivers/tty/sysrq.c
> > +++ b/drivers/tty/sysrq.c
> > @@ -382,6 +382,7 @@ static void moom_callback(struct work_struct *ignored)
> >               .memcg = NULL,
> >               .gfp_mask = gfp_mask,
> >               .order = -1,
> > +             .chosen_points = LONG_MIN,
>
> It would be better to do the initialization only once when we start
> evaluating tasks (select_bad_process).
>

I used to initialize it in constrained_alloc() in the previous
version, but I found that is not proper, so I change the
initialization in the definitions of each oom_control.
select_bad_process() should be a better choice. I will update it.

> >       };
> >
> >       mutex_lock(&oom_lock);
> > diff --git a/fs/proc/base.c b/fs/proc/base.c
> > index d86c0af..bf16406 100644
> > --- a/fs/proc/base.c
> > +++ b/fs/proc/base.c
> > @@ -551,8 +551,13 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
> >  {
> >       unsigned long totalpages = totalram_pages() + total_swap_pages;
> >       unsigned long points = 0;
> > +     long badness;
> >
> > -     points = oom_badness(task, totalpages) * 1000 / totalpages;
> > +     badness = oom_badness(task, totalpages);
> > +     if (badness != LONG_MIN) {
> > +             /* Let's keep the range of points as [0, 2000]. */
> > +             points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
> > +     }
> >       seq_printf(m, "%lu\n", points);
>
> This doesn't really work for OOM_SCORE_ADJ_MIN cases because they
> will simply print LONG_MIN rather than 0.
>

The point has be initlialize to 0:
unsigned long points = 0;

So for OOM_SCORE_ADJ_MIN cases, it will print 0,
seq_printf(m, "%lu\n", points);

But..

> So you want
>         /*
>          * Special case OOM_SCORE_ADJ_MIN for all others scale the
>          * badness value into [0, 2000] range which we have been
>          * exporting for a long time so userspace might depend on it
>          */

the comment is useful, I will update it with your comment.
Thanks.

>         if (badness == LONG_MIN)
>                 badness = 0;
>         else
>                 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3
>
> FTR. In my other email I was proposing to scale usage to the [-1000, 1000]
> range by
>         points = adj + usage * 1000/ totalpages
>
> this would make the math slightly easier to follow but then I've
> realized that this would be much less precise so what you have is
> better. Btw. we used to do that in the past until a7f638f999ff4
> which has changed that for this very reason.
>
> > @@ -107,7 +107,7 @@ static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
> >
> >  bool __oom_reap_task_mm(struct mm_struct *mm);
> >
> > -extern unsigned long oom_badness(struct task_struct *p,
> > +long oom_badness(struct task_struct *p,
> >               unsigned long totalpages);
>
> This is not really necessary.
>
> With that being addressed, you can add
> Acked-by: Michal Hocko <mhocko@suse.com>
>

Thanks for the review.
diff mbox series

Patch

diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 7c95afa9..e83fd46 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -382,6 +382,7 @@  static void moom_callback(struct work_struct *ignored)
 		.memcg = NULL,
 		.gfp_mask = gfp_mask,
 		.order = -1,
+		.chosen_points = LONG_MIN,
 	};
 
 	mutex_lock(&oom_lock);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d86c0af..bf16406 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -551,8 +551,13 @@  static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
 {
 	unsigned long totalpages = totalram_pages() + total_swap_pages;
 	unsigned long points = 0;
+	long badness;
 
-	points = oom_badness(task, totalpages) * 1000 / totalpages;
+	badness = oom_badness(task, totalpages);
+	if (badness != LONG_MIN) {
+		/* Let's keep the range of points as [0, 2000]. */
+		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
+	}
 	seq_printf(m, "%lu\n", points);
 
 	return 0;
diff --git a/include/linux/oom.h b/include/linux/oom.h
index c696c26..f022f58 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -48,7 +48,7 @@  struct oom_control {
 	/* Used by oom implementation, do not set */
 	unsigned long totalpages;
 	struct task_struct *chosen;
-	unsigned long chosen_points;
+	long chosen_points;
 
 	/* Used to print the constraint info. */
 	enum oom_constraint constraint;
@@ -107,7 +107,7 @@  static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
 
 bool __oom_reap_task_mm(struct mm_struct *mm);
 
-extern unsigned long oom_badness(struct task_struct *p,
+long oom_badness(struct task_struct *p,
 		unsigned long totalpages);
 
 extern bool out_of_memory(struct oom_control *oc);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1962232..df73b30 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1559,6 +1559,7 @@  static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 		.memcg = memcg,
 		.gfp_mask = gfp_mask,
 		.order = order,
+		.chosen_points = LONG_MIN,
 	};
 	bool ret;
 
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 6e94962..2dd5a90 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -196,17 +196,17 @@  static bool is_dump_unreclaim_slabs(void)
  * predictable as possible.  The goal is to return the highest value for the
  * task consuming the most memory to avoid subsequent oom failures.
  */
-unsigned long oom_badness(struct task_struct *p, unsigned long totalpages)
+long oom_badness(struct task_struct *p, unsigned long totalpages)
 {
 	long points;
 	long adj;
 
 	if (oom_unkillable_task(p))
-		return 0;
+		return LONG_MIN;
 
 	p = find_lock_task_mm(p);
 	if (!p)
-		return 0;
+		return LONG_MIN;
 
 	/*
 	 * Do not even consider tasks which are explicitly marked oom
@@ -218,7 +218,7 @@  unsigned long oom_badness(struct task_struct *p, unsigned long totalpages)
 			test_bit(MMF_OOM_SKIP, &p->mm->flags) ||
 			in_vfork(p)) {
 		task_unlock(p);
-		return 0;
+		return LONG_MIN;
 	}
 
 	/*
@@ -233,11 +233,7 @@  unsigned long oom_badness(struct task_struct *p, unsigned long totalpages)
 	adj *= totalpages / 1000;
 	points += adj;
 
-	/*
-	 * Never return 0 for an eligible task regardless of the root bonus and
-	 * oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here).
-	 */
-	return points > 0 ? points : 1;
+	return points;
 }
 
 static const char * const oom_constraint_text[] = {
@@ -336,12 +332,12 @@  static int oom_evaluate_task(struct task_struct *task, void *arg)
 	 * killed first if it triggers an oom, then select it.
 	 */
 	if (oom_task_origin(task)) {
-		points = ULONG_MAX;
+		points = LONG_MAX;
 		goto select;
 	}
 
 	points = oom_badness(task, oc->totalpages);
-	if (!points || points < oc->chosen_points)
+	if (points == LONG_MIN || points < oc->chosen_points)
 		goto next;
 
 select:
@@ -1128,6 +1124,7 @@  void pagefault_out_of_memory(void)
 		.memcg = NULL,
 		.gfp_mask = 0,
 		.order = 0,
+		.chosen_points = LONG_MIN,
 	};
 
 	if (mem_cgroup_oom_synchronize(true))
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e028b87c..8eec9d65 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3896,6 +3896,7 @@  void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
 		.memcg = NULL,
 		.gfp_mask = gfp_mask,
 		.order = order,
+		.chosen_points = LONG_MIN,
 	};
 	struct page *page;