From: Ido Schimmel <idosch@idosch.org>
To: iommu@lists.linux.dev
Cc: dwmw2@infradead.org, baolu.lu@linux.intel.com,
tglx@linutronix.de, peterz@infradead.org
Subject: Suspicious RCU usage in enable_drhd_fault_handling()
Date: Mon, 28 Oct 2024 10:43:45 +0200 [thread overview]
Message-ID: <Zx9OwdLIc_VoQ0-a@shredder.mtl.com> (raw)
Hi,
I have recently enabled CONFIG_RCU_EXPERT and CONFIG_PROVE_RCU_LIST in
our debug configuration file and started observing the following splat
[1] on one of our machines during boot. Searched the archives, but did
not find a similar report.
Not sure what is the right fix as I am not familiar with this code, but
I can easily test patches.
Thanks
[1]
smp: Bringing up secondary CPUs ...
smpboot: x86: Booting SMP configuration:
.... node #0, CPUs: #1 #2 #3
numa_add_cpu cpu 1 node 0: mask now 0-1
=============================
WARNING: suspicious RCU usage
6.12.0-rc4-custom-ge7e8d9b44a86 #1 Not tainted
-----------------------------
drivers/iommu/intel/dmar.c:2059 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/22:
#0: ffffffff8454e340 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x17e/0x7b0
#1: ffffffff84550ae0 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x17e/0x7b0
stack backtrace:
CPU: 1 UID: 0 PID: 22 Comm: cpuhp/1 Not tainted 6.12.0-rc4-custom-ge7e8d9b44a86 #1
Hardware name: Mellanox Technologies Ltd. MSN3800/VMOD0007, BIOS 5.11 01/06/2019
Call Trace:
<TASK>
dump_stack_lvl+0xf4/0x120
lockdep_rcu_suspicious+0x215/0x3c0
enable_drhd_fault_handling+0x316/0x3d0
cpuhp_invoke_callback+0x3c3/0x9c0
cpuhp_thread_fun+0x500/0x7b0
smpboot_thread_fn+0x680/0xa80
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
</TASK>
numa_add_cpu cpu 2 node 0: mask now 0-2
numa_add_cpu cpu 3 node 0: mask now 0-3
#4 #5 #6 #7
numa_add_cpu cpu 4 node 0: mask now 0-4
[...]
numa_add_cpu cpu 5 node 0: mask now 0-5
numa_add_cpu cpu 6 node 0: mask now 0-6
numa_add_cpu cpu 7 node 0: mask now 0-7
smp: Brought up 1 node, 8 CPUs
smpboot: Total of 8 processors activated (35120.16 BogoMIPS)
next reply other threads:[~2024-10-28 8:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-28 8:43 Ido Schimmel [this message]
2024-10-29 1:15 ` Suspicious RCU usage in enable_drhd_fault_handling() Baolu Lu
2025-01-16 13:34 ` Breno Leitao
2025-01-17 1:20 ` Baolu Lu
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