diff options
| author |   Qian Cai <cai@redhat.com> | 2020-10-28 14:26:14 -0400 |
|---|---|---|
| committer |   Will Deacon <will@kernel.org> | 2020-10-30 08:13:18 +0000 |
| commit | ce3d31ad3cac765484463b4f5a0b6b1f8f1a963e (patch) | |
| tree | 52d2d66433766f2cc4f0ba90bad4b551137f657a /arch/arm64/kernel/smp.c | |
| parent | arm64: Add workaround for Arm Cortex-A77 erratum 1508412 (diff) | |
| download | linux-dev-ce3d31ad3cac765484463b4f5a0b6b1f8f1a963e.tar.xz linux-dev-ce3d31ad3cac765484463b4f5a0b6b1f8f1a963e.zip | |
arm64/smp: Move rcu_cpu_starting() earlier
The call to rcu_cpu_starting() in secondary_start_kernel() is not early
enough in the CPU-hotplug onlining process, which results in lockdep
splats as follows:
WARNING: suspicious RCU usage
-----------------------------
kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
no locks held by swapper/1/0.
Call trace:
dump_backtrace+0x0/0x3c8
show_stack+0x14/0x60
dump_stack+0x14c/0x1c4
lockdep_rcu_suspicious+0x134/0x14c
__lock_acquire+0x1c30/0x2600
lock_acquire+0x274/0xc48
_raw_spin_lock+0xc8/0x140
vprintk_emit+0x90/0x3d0
vprintk_default+0x34/0x40
vprintk_func+0x378/0x590
printk+0xa8/0xd4
__cpuinfo_store_cpu+0x71c/0x868
cpuinfo_store_cpu+0x2c/0xc8
secondary_start_kernel+0x244/0x318
This is avoided by moving the call to rcu_cpu_starting up near the
beginning of the secondary_start_kernel() function.
Signed-off-by: Qian Cai <cai@redhat.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
Link: https://lore.kernel.org/r/20201028182614.13655-1-cai@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/smp.c')
| -rw-r--r-- | arch/arm64/kernel/smp.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 82e75fc2c903..09c96f57818c 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -222,6 +222,7 @@ asmlinkage notrace void secondary_start_kernel(void) if (system_uses_irq_prio_masking()) init_gic_priority_masking(); + rcu_cpu_starting(cpu); preempt_disable(); trace_hardirqs_off(); |