From: Ingo Molnar Sitsofe Wheeler reported a lockdep warning and bisected it down to: > commit c6531cce6e6e4b99bcda46b6268d6f2d9e30aea4 > Author: Ingo Molnar > Date: Mon May 12 21:21:14 2008 +0200 > > sched: do not trace sched_clock do not use raw irq flags in cpu_clock() as it causes lockdep to lose track of the true state of the IRQ flag. Reported-and-bisected-by: Sitsofe Wheeler Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton --- kernel/sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN kernel/sched.c~sched-sched_clock-lockdep-fix kernel/sched.c --- a/kernel/sched.c~sched-sched_clock-lockdep-fix +++ a/kernel/sched.c @@ -854,7 +854,7 @@ unsigned long long notrace cpu_clock(int unsigned long long prev_cpu_time, time, delta_time; unsigned long flags; - raw_local_irq_save(flags); + local_irq_save(flags); prev_cpu_time = per_cpu(prev_cpu_time, cpu); time = __cpu_clock(cpu) + per_cpu(time_offset, cpu); delta_time = time-prev_cpu_time; @@ -863,7 +863,7 @@ unsigned long long notrace cpu_clock(int time = __sync_cpu_clock(time, cpu); per_cpu(prev_cpu_time, cpu) = time; } - raw_local_irq_restore(flags); + local_irq_restore(flags); return time; } _