Re: INFO: rcu_preempt detected expedited stalls on CPUs/tasks (6.1.0-rc3): in cat /sys/kernel/debug/kmemleak

From: Mirsad Goran Todorovac
Date: Mon Nov 07 2022 - 04:53:34 EST

On 05. 11. 2022. 00:39, Mirsad Goran Todorovac wrote:

On 05. 11. 2022. 00:00, srinivas pandruvada wrote:

On Fri, 2022-11-04 at 23:01 +0100, Mirsad Goran Todorovac wrote:
Dear all,

When investigating thermald kmemleak, it occurred that the "cat
/sys/kernel/debug/kmemleak"
and "tail -20 /sys/kernel/debug/kmemleak" commands take unusual
amount
of time.

This memleak occurred because of bad element in the BIOS configuration
of _OSC method.
Unfortunately fixing this in ACPI interpreter can have other side
effects as this is not expected. So the ACPICA team
(https://acpica.org/community) is looking further.

Thanks,
Srinivas

Dear Mr. Srinivas,

Thank you for the update.

However, the investigation on thermald memleak had lead to discovery of the RCU stalls
in the kmemleak itself. I felt it correct to include you in Cc: because thermald caused the
leaks in question. I suspected myself it is the problem specific to my Lenovo Ideapad 3 Intel core
i5 laptop's BIOS, because I couldn't reproduce it on the other (desktop Lenovo) computer.

Thank you very much,
Mirsad

I felt it prudent to report that the issue is still present in 6.1.0-rc4 kernel:

Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004752] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 5-.... } 6 jiffies s: 1021 root: 0x20/.
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004777] rcu: blocking rcu_node structures (internal RCU debug):
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004782] Sending NMI from CPU 3 to CPUs 5:
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004796] NMI backtrace for cpu 5
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004802] CPU: 5 PID: 11912 Comm: tail Not tainted 6.1.0-rc4 #1
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004808] Hardware name: LENOVO 82H8/LNVNB161216, BIOS GGCN34WW 03/08/2022
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004810] RIP: 0010:kmemleak_seq_start+0x41/0x80
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004821] Code: e5 f5 a5 00 4c 63 e0 85 c0 78 40 e8 09 81 db ff 48 8b 05 d2 fe 88 01 4c 8d 60 f8 48 3d b0 63 03 ad 75 17 eb 32 49 8b 44 24 08 <48> 83 eb 01 4c 8d 60 f8 48 3d b0 63 03 ad 74 1d 48 85 db 7f e6 4c
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004825] RSP: 0018:ffffa7e621bc7cd8 EFLAGS: 00000202
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004829] RAX: ffff8efb493ae008 RBX: 00000000000418cd RCX: 0000000000000001
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004833] RDX: ffff8efc709da000 RSI: ffff8efb415937a8 RDI: ffffffffad036340
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004835] RBP: ffffa7e621bc7ce8 R08: 0000000000002000 R09: ffff8efb44502f80
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004837] R10: 0000000000020000 R11: 0000000000000000 R12: ffff8efb493af0a0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004839] R13: ffff8efb5c6d6200 R14: ffff8efb41593780 R15: ffffa7e621bc7ed8
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004841] FS:  00007f55020df740(0000) GS:ffff8efce8940000(0000) knlGS:0000000000000000
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004844] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004847] CR2: 00001d8300d0c000 CR3: 0000000266aaa003 CR4: 0000000000770ee0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004850] PKRU: 55555554
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004851] Call Trace:
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004853] <TASK>
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004856] seq_read_iter+0x169/0x420
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004862]  ? seq_read+0xad/0xe0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004867] seq_read+0xad/0xe0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004871] full_proxy_read+0x59/0x90
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004880] vfs_read+0xb2/0x2e0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004887] ksys_read+0x61/0xe0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004893] __x64_sys_read+0x1a/0x20
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004898] do_syscall_64+0x58/0x80
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004905]  ? common_interrupt+0x54/0xa0
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004911] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004917] RIP: 0033:0x7f5501f14992
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004922] Code: c0 e9 b2 fe ff ff 50 48 8d 3d fa b2 0c 00 e8 c5 1d 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004925] RSP: 002b:00007ffef4b4ce18 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004929] RAX: ffffffffffffffda RBX: 0000000000002000 RCX: 00007f5501f14992
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004931] RDX: 0000000000002000 RSI: 000055f43da40160 RDI: 0000000000000003
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004933] RBP: 000055f43da40160 R08: 000055f43da40fba R09: 000055f43da42180
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004935] R10: 0000000000000077 R11: 0000000000000246 R12: 0000000000000e5a
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004937] R13: 0000000000000003 R14: 000055f43da42180 R15: 0000000000000003
Nov  7 10:50:08 marvin-IdeaPad-3-15ITL6 kernel: [ 2369.004943] </TASK>

Thank you,
Mirsad

--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
--
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union