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| author | Oleg Nesterov <oleg@redhat.com> | 2013-08-06 18:08:44 +0200 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-08-13 21:05:57 -0400 |
| commit | 12473965c38a527a0c6f7a38d23edce60957f873 (patch) | |
| tree | 390d32b5ae485dda15302f370812bf668f5cdd87 /include/trace/ftrace.h | |
| parent | 36009d07b79d2a168d6037947357d96e5d8cebe7 (diff) | |
| download | op-kernel-dev-12473965c38a527a0c6f7a38d23edce60957f873.zip op-kernel-dev-12473965c38a527a0c6f7a38d23edce60957f873.tar.gz | |
tracing/perf: Reimplement TP_perf_assign() logic
The next patch tries to avoid the costly perf_trace_buf_* calls
when possible but there is a problem. We can only do this if
__task == NULL, perf_tp_event(task != NULL) has the additional
code for this case.
Unfortunately, TP_perf_assign/__perf_xxx which changes the default
values of __count/__task variables for perf_trace_buf_submit() is
called "too late", after we already did perf_trace_buf_prepare(),
and the optimization above can't work.
So this patch simply embeds __perf_xxx() into TP_ARGS(), this way
DECLARE_EVENT_CLASS() can use the result of assignments hidden in
"args" right after ftrace_get_offsets_##call() which is mostly
trivial. This allows us to have the fast-path "__task != NULL"
check at the start, see the next patch.
Link: http://lkml.kernel.org/r/20130806160844.GA2739@redhat.com
Tested-by: David Ahern <dsahern@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/trace/ftrace.h')
| -rw-r--r-- | include/trace/ftrace.h | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 618af05..4163d93 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -507,8 +507,14 @@ static inline notrace int ftrace_get_offsets_##call( \ #undef TP_fast_assign #define TP_fast_assign(args...) args -#undef TP_perf_assign -#define TP_perf_assign(args...) +#undef __perf_addr +#define __perf_addr(a) (a) + +#undef __perf_count +#define __perf_count(c) (c) + +#undef __perf_task +#define __perf_task(t) (t) #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -636,16 +642,13 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call #define __get_str(field) (char *)__get_dynamic_array(field) #undef __perf_addr -#define __perf_addr(a) __addr = (a) +#define __perf_addr(a) (__addr = (a)) #undef __perf_count -#define __perf_count(c) __count = (c) +#define __perf_count(c) (__count = (c)) #undef __perf_task -#define __perf_task(t) __task = (t) - -#undef TP_perf_assign -#define TP_perf_assign(args...) args +#define __perf_task(t) (__task = (t)) #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ |
