Hi, Thorsten here, the Linux kernel's regression tracker.
Frederic, I noticed a report about a regression in bugzilla.kernel.org
that appears to be caused by the following change of yours:
55d4669ef1b768 ("rcu: Fix rcu_barrier() VS post CPUHP_TEARDOWN_CPU
invocation")
As many (most?) kernel developers don't keep an eye on the bug tracker,
I decided to write this mail. To quote from
https://bugzilla.kernel.org/show_bug.cgi?id=219390:
> Mingcong Bai 2024-10-15 13:32:35 UTC
>
> Since aa162aa4aa383a0a714b1c36e8fcc77612ddd1a2 between v6.10.4 and
> v6.10.5, the Broadcom Tigon3 Ethernet interface (tg3) found on Apple
> MacBook Pro (15'', Mid 2010) would throw many rcu stall errors during
> boot up, causing peripherals such as the wireless card to misbehave:
>
> [ 24.153855] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 2-.... } 21 jiffies s: 973 root: 0x4/.
> [ 24.166938] rcu: blocking rcu_node structures (internal RCU debug):
> [ 24.177800] Sending NMI from CPU 3 to CPUs 2:
> [ 24.183113] NMI backtrace for cpu 2
> [ 24.183119] CPU: 2 PID: 1049 Comm: NetworkManager Not tainted 6.10.5-aosc-main #1
> [ 24.183123] Hardware name: Apple Inc. MacBookPro6,2/Mac-F22586C8, BIOS MBP61.88Z.005D.B00.1804100943 04/10/18
> [ 24.183125] RIP: 0010:__this_module+0x2d3d1/0x4f310 [tg3]
> [ 24.183135] Code: c3 cc cc cc cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 89 f6 48 03 77 30 8b 06 <31> f6 31 ff c3 cc cc cc cc 66 0f 1f 44 00 00 90 90 90 90 90 90 90
> [ 24.183138] RSP: 0018:ffffbf1a011d75e8 EFLAGS: 00000082
> [ 24.183141] RAX: 0000000000000000 RBX: ffffa04ec78f8a00 RCX: 0000000000000000
> [ 24.183143] RDX: 0000000000000000 RSI: ffffbf1a00fb007c RDI: ffffa04ec78f8a00
> [ 24.183145] RBP: 0000000000000b50 R08: 0000000000000000 R09: 0000000000000000
> [ 24.183147] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000216
> [ 24.183148] R13: ffffbf1a011d7624 R14: ffffa04ec78f8a08 R15: ffffa04ec78f8b40
> [ 24.183151] FS: 00007f4c524b2140(0000) GS:ffffa05007d00000(0000) knlGS:0000000000000000
> [ 24.183153] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 24.183155] CR2: 00007f7025eae3e8 CR3: 00000001040f8000 CR4: 00000000000006f0
> [ 24.183157] Call Trace:
> [ 24.183162] <NMI>
> [ 24.183167] ? nmi_cpu_backtrace+0xbf/0x140
> [ 24.183175] ? nmi_cpu_backtrace_handler+0x11/0x20
> [ 24.183181] ? nmi_handle+0x61/0x160
> [ 24.183186] ? default_do_nmi+0x42/0x110
> [ 24.183191] ? exc_nmi+0x1bd/0x290
> [ 24.183194] ? end_repeat_nmi+0xf/0x53
> [ 24.183203] ? __this_module+0x2d3d1/0x4f310 [tg3]
> [ 24.183207] ? __this_module+0x2d3d1/0x4f310 [tg3]
> [ 24.183210] ? __this_module+0x2d3d1/0x4f310 [tg3]
> [ 24.183213] </NMI>
> [ 24.183214] <TASK>
> [ 24.183215] __this_module+0x31828/0x4f310 [tg3]
> [ 24.183218] ? __this_module+0x2d390/0x4f310 [tg3]
> [ 24.183221] __this_module+0x398e6/0x4f310 [tg3]
> [ 24.183225] __this_module+0x3baf8/0x4f310 [tg3]
> [ 24.183229] __this_module+0x4733f/0x4f310 [tg3]
> [ 24.183233] ? _raw_spin_unlock_irqrestore+0x25/0x70
> [ 24.183237] ? __this_module+0x398e6/0x4f310 [tg3]
> [ 24.183241] __this_module+0x4b943/0x4f310 [tg3]
> [ 24.183244] ? delay_tsc+0x89/0xf0
> [ 24.183249] ? preempt_count_sub+0x51/0x60
> [ 24.183254] __this_module+0x4be4b/0x4f310 [tg3]
> [ 24.183258] __dev_open+0x103/0x1c0
> [ 24.183265] __dev_change_flags+0x1bd/0x230
> [ 24.183269] ? rtnl_getlink+0x362/0x400
> [ 24.183276] dev_change_flags+0x26/0x70
> [ 24.183280] do_setlink+0xe16/0x11f0
> [ 24.183286] ? __nla_validate_parse+0x61/0xd40
> [ 24.183295] __rtnl_newlink+0x63d/0x9f0
> [ 24.183301] ? kmem_cache_alloc_node_noprof+0x12b/0x360
> [ 24.183308] ? kmalloc_trace_noprof+0x11e/0x350
> [ 24.183312] ? rtnl_newlink+0x2e/0x70
> [ 24.183316] rtnl_newlink+0x47/0x70
> [ 24.183320] rtnetlink_rcv_msg+0x152/0x400
> [ 24.183324] ? __netlink_sendskb+0x68/0x90
> [ 24.183329] ? netlink_unicast+0x237/0x290
> [ 24.183333] ? __pfx_rtnetlink_rcv_msg+0x10/0x10
> [ 24.183336] netlink_rcv_skb+0x5b/0x110
> [ 24.183343] netlink_unicast+0x1a4/0x290
> [ 24.183347] netlink_sendmsg+0x222/0x4a0
> [ 24.183350] ? proc_get_long.constprop.0+0x116/0x210
> [ 24.183358] ____sys_sendmsg+0x379/0x3b0
> [ 24.183363] ? copy_msghdr_from_user+0x6d/0xb0
> [ 24.183368] ___sys_sendmsg+0x86/0xe0
> [ 24.183372] ? addrconf_sysctl_forward+0xf3/0x270
> [ 24.183378] ? _copy_from_iter+0x8b/0x570
> [ 24.183384] ? __pfx_addrconf_sysctl_forward+0x10/0x10
> [ 24.183388] ? _raw_spin_unlock+0x19/0x50
> [ 24.183392] ? proc_sys_call_handler+0xf3/0x2f0
> [ 24.183397] ? trace_hardirqs_on+0x29/0x90
> [ 24.183401] ? __fdget+0xc2/0xf0
> [ 24.183405] __sys_sendmsg+0x5b/0xc0
> [ 24.183410] ? syscall_trace_enter+0x110/0x1b0
> [ 24.183416] do_syscall_64+0x64/0x150
> [ 24.183423] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>
> I have bisected the error to this commit. Reverting it caused no new or
> perceivable issues on both the MacBook and a Zen4-based laptop.
[...]
>> Ohh, and when you say "causing peripherals such as the wireless card to
>> misbehave" what exactly do you mean?
>
> When the kernel throws rcu stall messages, the wireless card on the
> MacBook may fail to discover and/or connect to wireless networks - not a
> consistent behaviour but I suppose that something in the kernel got stuck.
See the ticket for more details and dmesg logs; the problem still
happens with 6.12-rc. The reporter is CCed.
Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.
P.S.: let me use this mail to also add the report to the list of tracked
regressions to ensure it's doesn't fall through the cracks:
#regzbot introduced: 55d4669ef1b76823083caecfab12a8bd2ccdcf64
#regzbot from: Mingcong Bai <jeffbai@xxxxxxx>
#regzbot duplicate: https://bugzilla.kernel.org/show_bug.cgi?id=219390
#regzbot title: rcu: wifi problems since tg3 started throwing rcu stall
warnings
#regzbot ignore-activity
