diff options
| author | Alexei Starovoitov <ast@fb.com> | 2016-04-06 18:43:22 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-07 21:04:26 -0400 |
| commit | ec5e099d6e941668d121ea9ca7057f4fa00830b0 (patch) | |
| tree | 4ec273d88501a68ce23eb53649530161a7fa8440 /include | |
| parent | b33b0a1bf69faff89693df49519fa7b459f5d807 (diff) | |
perf: optimize perf_fetch_caller_regs
avoid memset in perf_fetch_caller_regs, since it's the critical path of all tracepoints.
It's called from perf_sw_event_sched, perf_event_task_sched_in and all of perf_trace_##call
with this_cpu_ptr(&__perf_regs[..]) which are zero initialized by perpcu init logic and
subsequent call to perf_arch_fetch_caller_regs initializes the same fields on all archs,
so we can safely drop memset from all of the above cases and move it into
perf_ftrace_function_call that calls it with stack allocated pt_regs.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/perf_event.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index f291275ffd71..e89f7199c223 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -882,8 +882,6 @@ static inline void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned lo */ static inline void perf_fetch_caller_regs(struct pt_regs *regs) { - memset(regs, 0, sizeof(*regs)); - perf_arch_fetch_caller_regs(regs, CALLER_ADDR0); } |