ping ......
Shan Wei said, at 2012/11/19 13:21: > From: Shan Wei <davids...@tencent.com> > > __this_cpu_inc_return() or __this_cpu_dec generates a single instruction, > which is faster than __get_cpu_var operation. > > Signed-off-by: Shan Wei <davids...@tencent.com> > --- > kernel/trace/trace.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 18c0aa8..3795694 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -1313,7 +1313,7 @@ static void __ftrace_trace_stack(struct ring_buffer > *buffer, > */ > preempt_disable_notrace(); > > - use_stack = ++__get_cpu_var(ftrace_stack_reserve); > + use_stack = __this_cpu_inc_return(ftrace_stack_reserve); > /* > * We don't need any atomic variables, just a barrier. > * If an interrupt comes in, we don't care, because it would > @@ -1367,7 +1367,7 @@ static void __ftrace_trace_stack(struct ring_buffer > *buffer, > out: > /* Again, don't let gcc optimize things here */ > barrier(); > - __get_cpu_var(ftrace_stack_reserve)--; > + __this_cpu_dec(ftrace_stack_reserve); > preempt_enable_notrace(); > > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
