Commit-ID: 821465295b36136998ef294fe176fba4e09c1cd9 Gitweb: http://git.kernel.org/tip/821465295b36136998ef294fe176fba4e09c1cd9 Author: Shan Wei <davids...@tencent.com> AuthorDate: Mon, 19 Nov 2012 13:21:01 +0800 Committer: Steven Rostedt <rost...@goodmis.org> CommitDate: Fri, 25 Jan 2013 20:36:54 -0500
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.1060...@gmail.com Reviewed-by: Christoph Lameter <c...@linux.com> Signed-off-by: Shan Wei <davids...@tencent.com> Signed-off-by: Steven Rostedt <rost...@goodmis.org> --- kernel/trace/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ca9b7df..07888e1 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(); } -- 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/
