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authorWanpeng Li <kernellwp@gmail.com>2016-10-14 04:48:53 +0300
committerThomas Gleixner <tglx@linutronix.de>2016-10-14 15:14:20 +0300
commit1ec6ec14a2943f6f611fc1d5fb2d4eaa85bd9d72 (patch)
tree3ada863d9c60928176cd62b5b255566497465022 /arch/x86/kernel/smp.c
parentd4b05923f579c234137317cdf9a5eb69ddab76d1 (diff)
downloadlinux-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>
Diffstat (limited to 'arch/x86/kernel/smp.c')
-rw-r--r--arch/x86/kernel/smp.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 658777cf3851..ac2ee87deb55 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
*/