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| author | Wanpeng Li <kernellwp@gmail.com> | 2016-10-14 01:48:53 (GMT) |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-10-14 12:14:20 (GMT) |
| commit | 1ec6ec14a2943f6f611fc1d5fb2d4eaa85bd9d72 (patch) | |
| tree | 3ada863d9c60928176cd62b5b255566497465022 | |
| parent | d4b05923f579c234137317cdf9a5eb69ddab76d1 (diff) | |
| download | linux-1ec6ec14a2943f6f611fc1d5fb2d4eaa85bd9d72.tar.xz | |
x86/smp: Add irq_enter/exit() in smp_reschedule_interrupt()
===============================
[ INFO: suspicious RCU usage. ]
4.8.0+ #24 Not tainted
-------------------------------
./arch/x86/include/asm/msr-trace.h:47 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
no locks held by swapper/1/0.
[<ffffffff9d492b95>] do_trace_write_msr+0x135/0x140
[<ffffffff9d06f860>] native_write_msr+0x20/0x30
[<ffffffff9d065fad>] native_apic_msr_eoi_write+0x1d/0x30
[<ffffffff9d05bd1d>] smp_reschedule_interrupt+0x1d/0x30
[<ffffffff9d8daec6>] reschedule_interrupt+0x96/0xa0
Reschedule interrupt may be called in cpu idle state. This causes lockdep
check warning above.
Add irq_enter/exit() in smp_reschedule_interrupt(), irq_enter() tells the RCU
subsystems to end the extended quiescent state, so the following trace call in
ack_APIC_irq() works correctly.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/1476409733-5133-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/kernel/smp.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 658777c..ac2ee87 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -259,8 +259,10 @@ static inline void __smp_reschedule_interrupt(void) __visible void smp_reschedule_interrupt(struct pt_regs *regs) { + irq_enter(); ack_APIC_irq(); __smp_reschedule_interrupt(); + irq_exit(); /* * KVM uses this interrupt to force a cpu out of guest mode */ |