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| author | Shan Wei <davidshan@tencent.com> | 2012-11-19 13:21:01 +0800 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-01-25 20:36:54 -0500 |
| commit | 821465295b36136998ef294fe176fba4e09c1cd9 (patch) | |
| tree | 241bf19a408130332b123780b55fc8303fee491b | |
| parent | d75f717e19fe595e7efbf67de195ada8d89dfbbe (diff) | |
| download | linux-stable-821465295b36136998ef294fe176fba4e09c1cd9.tar.gz linux-stable-821465295b36136998ef294fe176fba4e09c1cd9.tar.bz2 linux-stable-821465295b36136998ef294fe176fba4e09c1cd9.zip | |
tracing: Use __this_cpu_inc/dec operation instead of __get_cpu_var
__this_cpu_inc_return() or __this_cpu_dec generates a single instruction,
which is faster than __get_cpu_var operation.
Link: http://lkml.kernel.org/r/50A9C1BD.1060308@gmail.com
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | 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 ca9b7dfed8ef..07888e15c694 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1344,7 +1344,7 @@ 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 @@ -1398,7 +1398,7 @@ 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(); } |