ltp or kvm triggerable lockdep alloc_pid() deadlock gripe
From: Mike Galbraith
Date: Thu Oct 22 2020 - 01:22:01 EST
Greetings,
The gripe below is repeatable in two ways here, boot with nomodeset so
nouveau doesn't steal the lockdep show when I then fire up one of my
(oink) full distro VM's, or from an ltp directory ./runltp -f cpuset
with the attached subset of controllers file placed in ./runtest dir.
Method2 may lead to a real deal deadlock, I've got a crashdump of one,
stack traces of uninterruptible sleepers attached.
[ 154.927302] ======================================================
[ 154.927303] WARNING: possible circular locking dependency detected
[ 154.927304] 5.9.1-rt18-rt #5 Tainted: G S E
[ 154.927305] ------------------------------------------------------
[ 154.927306] cpuset_inherit_/4992 is trying to acquire lock:
[ 154.927307] ffff9d334c5e64d8 (&s->seqcount){+.+.}-{0:0}, at: __slab_alloc.isra.87+0xad/0xc0
[ 154.927317]
but task is already holding lock:
[ 154.927317] ffffffffac4052d0 (pidmap_lock){+.+.}-{2:2}, at: alloc_pid+0x1fb/0x510
[ 154.927324]
which lock already depends on the new lock.
[ 154.927324]
the existing dependency chain (in reverse order) is:
[ 154.927325]
-> #1 (pidmap_lock){+.+.}-{2:2}:
[ 154.927328] lock_acquire+0x92/0x410
[ 154.927331] rt_spin_lock+0x2b/0xc0
[ 154.927335] free_pid+0x27/0xc0
[ 154.927338] release_task+0x34a/0x640
[ 154.927340] do_exit+0x6e9/0xcf0
[ 154.927342] kthread+0x11c/0x190
[ 154.927344] ret_from_fork+0x1f/0x30
[ 154.927347]
-> #0 (&s->seqcount){+.+.}-{0:0}:
[ 154.927350] validate_chain+0x981/0x1250
[ 154.927352] __lock_acquire+0x86f/0xbd0
[ 154.927354] lock_acquire+0x92/0x410
[ 154.927356] ___slab_alloc+0x71b/0x820
[ 154.927358] __slab_alloc.isra.87+0xad/0xc0
[ 154.927359] kmem_cache_alloc+0x700/0x8c0
[ 154.927361] radix_tree_node_alloc.constprop.22+0xa2/0xf0
[ 154.927365] idr_get_free+0x207/0x2b0
[ 154.927367] idr_alloc_u32+0x54/0xa0
[ 154.927369] idr_alloc_cyclic+0x4f/0xa0
[ 154.927370] alloc_pid+0x22b/0x510
[ 154.927372] copy_process+0xeb5/0x1de0
[ 154.927375] _do_fork+0x52/0x750
[ 154.927377] __do_sys_clone+0x64/0x70
[ 154.927379] do_syscall_64+0x33/0x40
[ 154.927382] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 154.927384]
other info that might help us debug this:
[ 154.927384] Possible unsafe locking scenario:
[ 154.927385] CPU0 CPU1
[ 154.927386] ---- ----
[ 154.927386] lock(pidmap_lock);
[ 154.927388] lock(&s->seqcount);
[ 154.927389] lock(pidmap_lock);
[ 154.927391] lock(&s->seqcount);
[ 154.927392]
*** DEADLOCK ***
[ 154.927393] 4 locks held by cpuset_inherit_/4992:
[ 154.927394] #0: ffff9d33decea5b0 ((lock).lock){+.+.}-{2:2}, at: __radix_tree_preload+0x52/0x3b0
[ 154.927399] #1: ffffffffac598fa0 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0x5/0xc0
[ 154.927405] #2: ffffffffac4052d0 (pidmap_lock){+.+.}-{2:2}, at: alloc_pid+0x1fb/0x510
[ 154.927409] #3: ffffffffac598fa0 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0x5/0xc0
[ 154.927414]
stack backtrace:
[ 154.927416] CPU: 3 PID: 4992 Comm: cpuset_inherit_ Kdump: loaded Tainted: G S E 5.9.1-rt18-rt #5
[ 154.927418] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013
[ 154.927419] Call Trace:
[ 154.927422] dump_stack+0x77/0x9b
[ 154.927425] check_noncircular+0x148/0x160
[ 154.927432] ? validate_chain+0x981/0x1250
[ 154.927435] validate_chain+0x981/0x1250
[ 154.927441] __lock_acquire+0x86f/0xbd0
[ 154.927446] lock_acquire+0x92/0x410
[ 154.927449] ? __slab_alloc.isra.87+0xad/0xc0
[ 154.927452] ? kmem_cache_alloc+0x648/0x8c0
[ 154.927453] ? lock_acquire+0x92/0x410
[ 154.927458] ___slab_alloc+0x71b/0x820
[ 154.927460] ? __slab_alloc.isra.87+0xad/0xc0
[ 154.927463] ? radix_tree_node_alloc.constprop.22+0xa2/0xf0
[ 154.927468] ? __slab_alloc.isra.87+0x83/0xc0
[ 154.927472] ? radix_tree_node_alloc.constprop.22+0xa2/0xf0
[ 154.927474] ? __slab_alloc.isra.87+0xad/0xc0
[ 154.927476] __slab_alloc.isra.87+0xad/0xc0
[ 154.927480] ? radix_tree_node_alloc.constprop.22+0xa2/0xf0
[ 154.927482] kmem_cache_alloc+0x700/0x8c0
[ 154.927487] radix_tree_node_alloc.constprop.22+0xa2/0xf0
[ 154.927491] idr_get_free+0x207/0x2b0
[ 154.927495] idr_alloc_u32+0x54/0xa0
[ 154.927500] idr_alloc_cyclic+0x4f/0xa0
[ 154.927503] alloc_pid+0x22b/0x510
[ 154.927506] ? copy_thread+0x88/0x200
[ 154.927512] copy_process+0xeb5/0x1de0
[ 154.927520] _do_fork+0x52/0x750
[ 154.927523] ? lock_acquire+0x92/0x410
[ 154.927525] ? __might_fault+0x3e/0x90
[ 154.927530] ? find_held_lock+0x2d/0x90
[ 154.927535] __do_sys_clone+0x64/0x70
[ 154.927541] do_syscall_64+0x33/0x40
[ 154.927544] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 154.927546] RIP: 0033:0x7f0b357356e3
[ 154.927548] Code: db 45 85 ed 0f 85 ad 01 00 00 64 4c 8b 04 25 10 00 00 00 31 d2 4d 8d 90 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f1 00 00 00 85 c0 41 89 c4 0f 85 fe 00 00
[ 154.927550] RSP: 002b:00007ffdfd6d15f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
[ 154.927552] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0b357356e3
[ 154.927554] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
[ 154.927555] RBP: 00007ffdfd6d1620 R08: 00007f0b36052b80 R09: 0000000000000072
[ 154.927556] R10: 00007f0b36052e50 R11: 0000000000000246 R12: 0000000000000000
[ 154.927557] R13: 0000000000000000 R14: 0000000000000000 R15: 00005614ef57ecf0
#DESCRIPTION:Resource Management testing
cpuset_base_ops cpuset_base_ops_testset.sh
cpuset_inherit cpuset_inherit_testset.sh
cpuset_exclusive cpuset_exclusive_test.sh
cpuset_hierarchy cpuset_hierarchy_test.sh
cpuset_syscall cpuset_syscall_testset.sh
cpuset_sched_domains cpuset_sched_domains_test.sh
cpuset_load_balance cpuset_load_balance_test.sh
cpuset_hotplug cpuset_hotplug_test.sh
cpuset_memory cpuset_memory_testset.sh
cpuset_memory_pressure cpuset_memory_pressure_testset.sh
cpuset_memory_spread cpuset_memory_spread_testset.sh
cpuset_regression_test cpuset_regression_test.sh
1 0 2 ffffa09c87fd0000 UN 0.1 221032 9368 systemd
627 1 0 ffffa09f733c0000 UN 0.0 68392 7004 systemd-udevd
3322 3247 7 ffffa09f512051c0 UN 0.0 167624 2732 gpg-agent
3841 3468 2 ffffa09f32250000 UN 0.1 19912 9828 bash
4209 3468 2 ffffa09dd070d1c0 UN 0.1 19912 9796 bash
4845 3335 3 ffffa09f2ffe1b40 UN 0.1 268172 24880 file.so
4846 3335 5 ffffa09f2d418000 UN 0.1 268172 24880 file.so
5657 1 3 ffffa09f222e3680 UN 1.5 2884604 260248 Thread (pooled)
6716 5797 3 ffffa09f30da1b40 UN 0.0 14128 4168 cpuset_hotplug_
6743 1 3 ffffa09f54151b40 UN 0.1 574864 18532 pool-/usr/lib/x
6744 1 4 ffffa09f357f9b40 UN 0.0 489516 6096 pool-/usr/lib/x
PID: 1 TASK: ffffa09c87fd0000 CPU: 2 COMMAND: "systemd"
#0 [ffffbfbb00033c50] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb00033cd8] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb00033ce8] __rt_mutex_slowlock+56 at ffffffffa59b3868
#3 [ffffbfbb00033d30] rt_mutex_slowlock_locked+207 at ffffffffa59b3abf
#4 [ffffbfbb00033d88] rt_mutex_slowlock.constprop.30+90 at ffffffffa59b3d3a
#5 [ffffbfbb00033e00] proc_cgroup_show+74 at ffffffffa5184a7a
#6 [ffffbfbb00033e48] proc_single_show+84 at ffffffffa53cd524
#7 [ffffbfbb00033e80] seq_read+206 at ffffffffa534c30e
#8 [ffffbfbb00033ed8] vfs_read+209 at ffffffffa531d281
#9 [ffffbfbb00033f08] ksys_read+135 at ffffffffa531d637
#10 [ffffbfbb00033f40] do_syscall_64+51 at ffffffffa59a35c3
#11 [ffffbfbb00033f50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f1bb97dd1d8 RSP: 00007ffd5f424ac0 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 000055e3b1224cc0 RCX: 00007f1bb97dd1d8
RDX: 0000000000000400 RSI: 000055e3b1224cc0 RDI: 0000000000000055
RBP: 0000000000000400 R8: 0000000000000000 R9: 0000000000000000
R10: 00007f1bbb1f9940 R11: 0000000000000246 R12: 00007f1bb9aa57a0
R13: 00007f1bb9aa62e0 R14: 0000000000000000 R15: 000055e3b1377f20
ORIG_RAX: 0000000000000000 CS: 0033 SS: 002b
PID: 627 TASK: ffffa09f733c0000 CPU: 0 COMMAND: "systemd-udevd"
#0 [ffffbfbb00b6fc38] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb00b6fcc0] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb00b6fcc8] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb00b6fd28] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb00b6fd40] cgroup_can_fork+1321 at ffffffffa5185e69
#5 [ffffbfbb00b6fd88] copy_process+4457 at ffffffffa508aab9
#6 [ffffbfbb00b6fe30] _do_fork+82 at ffffffffa508b882
#7 [ffffbfbb00b6fed0] __do_sys_clone+100 at ffffffffa508c054
#8 [ffffbfbb00b6ff40] do_syscall_64+51 at ffffffffa59a35c3
#9 [ffffbfbb00b6ff50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007fa6261286e3 RSP: 00007ffc0a16daf0 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007ffc0a16daf0 RCX: 00007fa6261286e3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffc0a16db40 R8: 00007fa6272cfd40 R9: 0000000000000001
R10: 00007fa6272d0010 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000557a3d4a9a10
ORIG_RAX: 0000000000000038 CS: 0033 SS: 002b
PID: 3322 TASK: ffffa09f512051c0 CPU: 7 COMMAND: "gpg-agent"
#0 [ffffbfbb00ef7c38] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb00ef7cc0] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb00ef7cc8] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb00ef7d28] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb00ef7d40] cgroup_can_fork+1321 at ffffffffa5185e69
#5 [ffffbfbb00ef7d88] copy_process+4457 at ffffffffa508aab9
#6 [ffffbfbb00ef7e30] _do_fork+82 at ffffffffa508b882
#7 [ffffbfbb00ef7ed0] __do_sys_clone+100 at ffffffffa508c054
#8 [ffffbfbb00ef7f40] do_syscall_64+51 at ffffffffa59a35c3
#9 [ffffbfbb00ef7f50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f4355ee7fb1 RSP: 00007ffdf3130358 RFLAGS: 00000202
RAX: ffffffffffffffda RBX: 00007f4355be7700 RCX: 00007f4355ee7fb1
RDX: 00007f4355be79d0 RSI: 00007f4355be6fb0 RDI: 00000000003d0f00
RBP: 00007ffdf3130760 R8: 00007f4355be7700 R9: 00007f4355be7700
R10: 00007f4355be79d0 R11: 0000000000000202 R12: 00007ffdf31303fe
R13: 00007ffdf31303ff R14: 000055667da0f9e0 R15: 00007ffdf3130760
ORIG_RAX: 0000000000000038 CS: 0033 SS: 002b
PID: 3841 TASK: ffffa09f32250000 CPU: 2 COMMAND: "bash"
#0 [ffffbfbb02d0fc38] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb02d0fcc0] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb02d0fcc8] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb02d0fd28] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb02d0fd40] cgroup_can_fork+1321 at ffffffffa5185e69
#5 [ffffbfbb02d0fd88] copy_process+4457 at ffffffffa508aab9
#6 [ffffbfbb02d0fe30] _do_fork+82 at ffffffffa508b882
#7 [ffffbfbb02d0fed0] __do_sys_clone+100 at ffffffffa508c054
#8 [ffffbfbb02d0ff40] do_syscall_64+51 at ffffffffa59a35c3
#9 [ffffbfbb02d0ff50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f023eaf36e3 RSP: 00007ffe80698a30 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f023eaf36e3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe80698a60 R8: 00007f023f410b80 R9: 0000000000000000
R10: 00007f023f410e50 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000562cd4ee6c90 R15: 0000562cd4ee6c90
ORIG_RAX: 0000000000000038 CS: 0033 SS: 002b
PID: 4209 TASK: ffffa09dd070d1c0 CPU: 2 COMMAND: "bash"
#0 [ffffbfbb0376fc38] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb0376fcc0] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb0376fcc8] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb0376fd28] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb0376fd40] cgroup_can_fork+1321 at ffffffffa5185e69
#5 [ffffbfbb0376fd88] copy_process+4457 at ffffffffa508aab9
#6 [ffffbfbb0376fe30] _do_fork+82 at ffffffffa508b882
#7 [ffffbfbb0376fed0] __do_sys_clone+100 at ffffffffa508c054
#8 [ffffbfbb0376ff40] do_syscall_64+51 at ffffffffa59a35c3
#9 [ffffbfbb0376ff50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f81a96426e3 RSP: 00007ffd97e5ebc0 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f81a96426e3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd97e5ebf0 R8: 00007f81a9f5fb80 R9: 0000000000000000
R10: 00007f81a9f5fe50 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 000055a56fcb9c90 R15: 000055a56fcb9c90
ORIG_RAX: 0000000000000038 CS: 0033 SS: 002b
PID: 4845 TASK: ffffa09f2ffe1b40 CPU: 3 COMMAND: "file.so"
#0 [ffffbfbb03223d88] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb03223e10] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb03223e18] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb03223e78] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb03223e90] exit_signals+711 at ffffffffa50a2f27
#5 [ffffbfbb03223ea8] do_exit+216 at ffffffffa5093ef8
#6 [ffffbfbb03223f10] do_group_exit+71 at ffffffffa5094bb7
#7 [ffffbfbb03223f38] __x64_sys_exit_group+20 at ffffffffa5094c34
#8 [ffffbfbb03223f40] do_syscall_64+51 at ffffffffa59a35c3
#9 [ffffbfbb03223f50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f0ca6b20998 RSP: 00007ffc5e1eef48 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0ca6b20998
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00007f0ca6e0d510 R8: 00000000000000e7 R9: ffffffffffffff60
R10: 00007f0ca5fd10f8 R11: 0000000000000246 R12: 00007f0ca6e0d510
R13: 00007f0ca6e0d8c0 R14: 00007ffc5e1eefe0 R15: 0000000000000020
ORIG_RAX: 00000000000000e7 CS: 0033 SS: 002b
PID: 4846 TASK: ffffa09f2d418000 CPU: 5 COMMAND: "file.so"
#0 [ffffbfbb0396fd88] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb0396fe10] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb0396fe18] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb0396fe78] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb0396fe90] exit_signals+711 at ffffffffa50a2f27
#5 [ffffbfbb0396fea8] do_exit+216 at ffffffffa5093ef8
#6 [ffffbfbb0396ff10] do_group_exit+71 at ffffffffa5094bb7
#7 [ffffbfbb0396ff38] __x64_sys_exit_group+20 at ffffffffa5094c34
#8 [ffffbfbb0396ff40] do_syscall_64+51 at ffffffffa59a35c3
#9 [ffffbfbb0396ff50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f0ca6b20998 RSP: 00007ffc5e1eef48 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0ca6b20998
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00007f0ca6e0d510 R8: 00000000000000e7 R9: ffffffffffffff60
R10: 00007f0ca5fd10f8 R11: 0000000000000246 R12: 00007f0ca6e0d510
R13: 00007f0ca6e0d8c0 R14: 00007ffc5e1eefe0 R15: 0000000000000020
ORIG_RAX: 00000000000000e7 CS: 0033 SS: 002b
PID: 5657 TASK: ffffa09f222e3680 CPU: 3 COMMAND: "Thread (pooled)"
#0 [ffffbfbb03a07db0] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb03a07e38] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb03a07e40] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb03a07ea0] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb03a07eb8] exit_signals+711 at ffffffffa50a2f27
#5 [ffffbfbb03a07ed0] do_exit+216 at ffffffffa5093ef8
#6 [ffffbfbb03a07f38] __x64_sys_exit+23 at ffffffffa5094b67
#7 [ffffbfbb03a07f40] do_syscall_64+51 at ffffffffa59a35c3
#8 [ffffbfbb03a07f50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f1f2f9265b6 RSP: 00007f1e95057d50 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007f1e95058700 RCX: 00007f1f2f9265b6
RDX: 000000000000003c RSI: 00007f1f2fb38010 RDI: 0000000000000000
RBP: 0000000000000000 R8: 00007f1e880029c0 R9: 0000000000000000
R10: 0000000000000020 R11: 0000000000000246 R12: 00007ffd7582f27e
R13: 00007ffd7582f27f R14: 000055fce0818180 R15: 00007ffd7582f350
ORIG_RAX: 000000000000003c CS: 0033 SS: 002b
PID: 6716 TASK: ffffa09f30da1b40 CPU: 3 COMMAND: "cpuset_hotplug_"
#0 [ffffbfbb03ac79d8] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb03ac7a60] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb03ac7a70] schedule_timeout+495 at ffffffffa59b4cbf
#3 [ffffbfbb03ac7b08] wait_for_completion+165 at ffffffffa59b2f25
#4 [ffffbfbb03ac7b48] affine_move_task+705 at ffffffffa50cc231
#5 [ffffbfbb03ac7c88] __set_cpus_allowed_ptr+274 at ffffffffa50cc562
#6 [ffffbfbb03ac7cc8] cpuset_attach+195 at ffffffffa518df73
#7 [ffffbfbb03ac7d00] cgroup_migrate_execute+1133 at ffffffffa518075d
#8 [ffffbfbb03ac7d58] cgroup_attach_task+524 at ffffffffa5180abc
#9 [ffffbfbb03ac7e28] __cgroup1_procs_write.constprop.21+243 at ffffffffa5187843
#10 [ffffbfbb03ac7e68] cgroup_file_write+126 at ffffffffa517b07e
#11 [ffffbfbb03ac7ea0] kernfs_fop_write+275 at ffffffffa53e1c13
#12 [ffffbfbb03ac7ed8] vfs_write+240 at ffffffffa531d470
#13 [ffffbfbb03ac7f08] ksys_write+135 at ffffffffa531d737
#14 [ffffbfbb03ac7f40] do_syscall_64+51 at ffffffffa59a35c3
#15 [ffffbfbb03ac7f50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f0176b84244 RSP: 00007ffffcf7e2b8 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f0176b84244
RDX: 0000000000000005 RSI: 000055b15203d890 RDI: 0000000000000001
RBP: 000055b15203d890 R8: 000000000000000a R9: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000005
R13: 0000000000000001 R14: 00007f0176e4c5a0 R15: 0000000000000005
ORIG_RAX: 0000000000000001 CS: 0033 SS: 002b
PID: 6743 TASK: ffffa09f54151b40 CPU: 3 COMMAND: "pool-/usr/lib/x"
#0 [ffffbfbb08657db0] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb08657e38] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb08657e40] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb08657ea0] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb08657eb8] exit_signals+711 at ffffffffa50a2f27
#5 [ffffbfbb08657ed0] do_exit+216 at ffffffffa5093ef8
#6 [ffffbfbb08657f38] __x64_sys_exit+23 at ffffffffa5094b67
#7 [ffffbfbb08657f40] do_syscall_64+51 at ffffffffa59a35c3
#8 [ffffbfbb08657f50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007f0176d6b5b6 RSP: 00007f015d540dd0 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007f015d541700 RCX: 00007f0176d6b5b6
RDX: 000000000000003c RSI: 00007f0176f7d010 RDI: 0000000000000000
RBP: 0000000000000000 R8: 00007f01500008c0 R9: 0000000000000004
R10: 000055ee65f185d0 R11: 0000000000000246 R12: 00007ffc71eef56e
R13: 00007ffc71eef56f R14: 00007f01640038f0 R15: 00007ffc71eef600
ORIG_RAX: 000000000000003c CS: 0033 SS: 002b
PID: 6744 TASK: ffffa09f357f9b40 CPU: 4 COMMAND: "pool-/usr/lib/x"
#0 [ffffbfbb0865fdb0] __schedule+837 at ffffffffa59b15f5
#1 [ffffbfbb0865fe38] schedule+86 at ffffffffa59b1d96
#2 [ffffbfbb0865fe40] percpu_rwsem_wait+181 at ffffffffa5101b75
#3 [ffffbfbb0865fea0] __percpu_down_read+114 at ffffffffa5101ec2
#4 [ffffbfbb0865feb8] exit_signals+711 at ffffffffa50a2f27
#5 [ffffbfbb0865fed0] do_exit+216 at ffffffffa5093ef8
#6 [ffffbfbb0865ff38] __x64_sys_exit+23 at ffffffffa5094b67
#7 [ffffbfbb0865ff40] do_syscall_64+51 at ffffffffa59a35c3
#8 [ffffbfbb0865ff50] entry_SYSCALL_64_after_hwframe+68 at ffffffffa5a0008c
RIP: 00007ff49b0c85b6 RSP: 00007ff493ffedd0 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007ff493fff700 RCX: 00007ff49b0c85b6
RDX: 000000000000003c RSI: 00007ff49b2da010 RDI: 0000000000000000
RBP: 0000000000000000 R8: 00007ff488001600 R9: 0000000000000000
R10: 0000000000000050 R11: 0000000000000246 R12: 00007ffdc88c817e
R13: 00007ffdc88c817f R14: 00007ff48c0069e0 R15: 00007ffdc88c8210
ORIG_RAX: 000000000000003c CS: 0033 SS: 002b