From: John Ogness <john.ogness@linutronix.de>
To: paulmck@kernel.org
Cc: Frederic Weisbecker <frederic@kernel.org>,
rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-team@fb.com, rostedt@goodmis.org, tglx@linutronix.de,
pmladek@suse.com
Subject: Re: [PATCH v2 rcu 0/8] NMI-safe SRCU reader API
Date: Thu, 27 Oct 2022 11:37:46 +0206 [thread overview]
Message-ID: <874jvpehod.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <20221024134727.GV5600@paulmck-ThinkPad-P17-Gen-1>
Hi Paul,
I am running some tests using srcunmisafe.2022.10.21a and I am hitting
the WARN_ONCE in srcu_check_nmi_safety():
[ 1.836703][ T1] rcu: Hierarchical SRCU implementation.
[ 1.836707][ T1] rcu: Max phase no-delay instances is 1000.
[ 1.836844][ T15] ------------[ cut here ]------------
[ 1.836846][ T15] CPU 0 old state 1 new state 2
[ 1.836885][ T15] WARNING: CPU: 0 PID: 15 at kernel/rcu/srcutree.c:652 srcu_check_nmi_safety+0x79/0x90
[ 1.836897][ T15] Modules linked in:
[ 1.836903][ T15] CPU: 0 PID: 15 Comm: pr/bkl Not tainted 6.1.0-rc1+ #9
[ 1.836909][ T15] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[ 1.836912][ T15] RIP: 0010:srcu_check_nmi_safety+0x79/0x90
[ 1.836919][ T15] Code: d3 80 3d 9f 76 d3 01 00 75 e5 55 8b b0 c8 01 00 00 44 89 c1 48 c7 c7 d0 1f 87 82 c6 05 850
[ 1.836923][ T15] RSP: 0000:ffffc90000083e98 EFLAGS: 00010282
[ 1.836929][ T15] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 1.836933][ T15] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000ffffffff
[ 1.836936][ T15] RBP: ffffc90000083e98 R08: 0000000000000000 R09: 0000000000000001
[ 1.836940][ T15] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[ 1.836943][ T15] R13: ffffc90000013d70 R14: ffff888004073900 R15: 0000000000000000
[ 1.836946][ T15] FS: 0000000000000000(0000) GS:ffff888019600000(0000) knlGS:0000000000000000
[ 1.836951][ T15] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.836954][ T15] CR2: ffff888003c01000 CR3: 0000000002c22001 CR4: 0000000000370ef0
[ 1.836962][ T15] Call Trace:
[ 1.836964][ T15] <TASK>
[ 1.836970][ T15] console_bkl_kthread_func+0x27a/0x590
[ 1.836981][ T15] ? _raw_spin_unlock_irqrestore+0x3c/0x60
[ 1.836998][ T15] ? console_fill_outbuf+0x210/0x210
[ 1.837003][ T15] kthread+0x108/0x130
[ 1.837012][ T15] ? kthread_complete_and_exit+0x20/0x20
[ 1.837025][ T15] ret_from_fork+0x1f/0x30
[ 1.837059][ T15] </TASK>
[ 1.837062][ T15] irq event stamp: 71
[ 1.837065][ T15] hardirqs last enabled at (73): [<ffffffff81106f99>] vprintk_store+0x1b9/0x5e0
[ 1.837070][ T15] hardirqs last disabled at (74): [<ffffffff811071fb>] vprintk_store+0x41b/0x5e0
[ 1.837075][ T15] softirqs last enabled at (0): [<ffffffff8107ce22>] copy_process+0x952/0x1dd0
[ 1.837081][ T15] softirqs last disabled at (0): [<0000000000000000>] 0x0
[ 1.837085][ T15] ---[ end trace 0000000000000000 ]---
[ 1.945054][ T12] Callback from call_rcu_tasks_rude() invoked.
My code is calling srcu_read_lock_nmisafe() from task context, in a
dedicated kthread. I am using DEFINE_STATIC_SRCU() to define/initialize
the srcu struct.
What does the warning imply?
John Ogness
next prev parent reply other threads:[~2022-10-27 9:33 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-21 14:46 [PATCH rcu 0/4] NMI-safe SRCU reader API Paul E. McKenney
2022-09-21 14:46 ` [PATCH RFC rcu 1/4] srcu: Convert ->srcu_lock_count and ->srcu_unlock_count to atomic Paul E. McKenney
2022-09-21 14:46 ` [PATCH RFC rcu 2/4] srcu: Create and srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe() Paul E. McKenney
2022-09-21 14:46 ` [PATCH RFC rcu 3/4] srcu: Check for consistent per-CPU per-srcu_struct NMI safety Paul E. McKenney
2022-09-21 14:46 ` [PATCH RFC rcu 4/4] srcu: Check for consistent global " Paul E. McKenney
2022-09-29 18:07 ` [PATCH v2 rcu 0/8] NMI-safe SRCU reader API Paul E. McKenney
2022-09-29 18:07 ` [PATCH RFC v2 rcu 1/8] srcu: Convert ->srcu_lock_count and ->srcu_unlock_count to atomic Paul E. McKenney
2022-09-30 15:02 ` John Ogness
2022-09-30 15:35 ` Paul E. McKenney
2022-09-30 20:37 ` John Ogness
2022-10-01 16:51 ` Paul E. McKenney
2022-09-29 18:07 ` [PATCH RFC v2 rcu 2/8] srcu: Create an srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe() Paul E. McKenney
2022-10-02 15:55 ` Frederic Weisbecker
2022-10-02 15:57 ` Frederic Weisbecker
2022-10-02 16:10 ` Paul E. McKenney
2022-10-02 16:09 ` Paul E. McKenney
2022-10-02 21:47 ` Frederic Weisbecker
2022-10-02 23:46 ` Paul E. McKenney
2022-10-03 9:55 ` Frederic Weisbecker
2022-10-03 11:52 ` Paul E. McKenney
2022-10-18 14:31 ` John Ogness
2022-10-18 15:18 ` Paul E. McKenney
2022-09-29 18:07 ` [PATCH RFC v2 rcu 3/8] srcu: Check for consistent per-CPU per-srcu_struct NMI safety Paul E. McKenney
2022-10-02 22:06 ` Frederic Weisbecker
2022-10-02 23:51 ` Paul E. McKenney
2022-10-03 10:13 ` Frederic Weisbecker
2022-10-03 11:57 ` Paul E. McKenney
2022-10-03 12:37 ` Frederic Weisbecker
2022-10-03 13:32 ` Paul E. McKenney
2022-10-03 13:36 ` Frederic Weisbecker
2022-09-29 18:07 ` [PATCH RFC v2 rcu 4/8] srcu: Check for consistent global " Paul E. McKenney
2022-09-29 18:07 ` [PATCH RFC v2 rcu 5/8] arch/x86: Add ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option Paul E. McKenney
2022-09-29 18:07 ` [PATCH RFC v2 rcu 6/8] arch/arm64: " Paul E. McKenney
2022-09-29 18:07 ` Paul E. McKenney
2022-10-05 11:12 ` Mark Rutland
2022-10-05 11:12 ` Mark Rutland
2022-09-29 18:07 ` [PATCH RFC v2 rcu 7/8] arch/loongarch: " Paul E. McKenney
2022-09-29 18:07 ` [PATCH RFC v2 rcu 8/8] arch/s390: " Paul E. McKenney
2022-10-03 14:11 ` [PATCH v2 rcu 0/8] NMI-safe SRCU reader API Frederic Weisbecker
2022-10-03 16:38 ` Paul E. McKenney
2022-10-14 22:47 ` Joel Fernandes
2022-10-14 22:52 ` Joel Fernandes
2022-10-18 10:33 ` John Ogness
2022-10-18 15:24 ` Paul E. McKenney
2022-10-18 18:44 ` John Ogness
2022-10-18 18:59 ` Paul E. McKenney
2022-10-18 21:57 ` Paul E. McKenney
2022-10-19 11:13 ` John Ogness
2022-10-19 19:14 ` Paul E. McKenney
2022-10-19 21:38 ` John Ogness
2022-10-19 22:05 ` Frederic Weisbecker
2022-10-20 22:27 ` Paul E. McKenney
2022-10-20 22:41 ` Paul E. McKenney
2022-10-21 12:27 ` John Ogness
2022-10-21 13:59 ` Paul E. McKenney
2022-10-21 18:41 ` Paul E. McKenney
2022-10-24 6:15 ` John Ogness
2022-10-24 13:47 ` Paul E. McKenney
2022-10-27 9:31 ` John Ogness [this message]
2022-10-27 14:10 ` Paul E. McKenney
2022-10-27 14:39 ` John Ogness
2022-10-27 16:01 ` Paul E. McKenney
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