lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

perf/ftrace: Optimize perf/tracepoint interaction for single events

Browse Source 
When we've got but a single event per tracepoint
there is no reason to try and multiplex it so don't.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2010-05-18 18:08:32 +02:00
committed by Ingo Molnar
parent ef4f30f54e
commit 4f41c013f5
7 changed files with 31 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
kernel/trace/trace_event_perf.c
View File

@@ -27,13 +27,15 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
/* Count the events in use (per event id, not per instance) */
static int total_ref_count;
static int perf_trace_event_enable(struct ftrace_event_call *event)
static int perf_trace_event_enable(struct ftrace_event_call *event, void *data)
{
char *buf;
int ret = -ENOMEM;
if (event->perf_refcount++ > 0)
if (event->perf_refcount++ > 0) {
event->perf_data = NULL;
return 0;
}
if (!total_ref_count) {
buf = (char *)alloc_percpu(perf_trace_t);
@@ -51,6 +53,7 @@ static int perf_trace_event_enable(struct ftrace_event_call *event)
ret = event->perf_event_enable(event);
if (!ret) {
event->perf_data = data;
total_ref_count++;
return 0;
}
@@ -68,7 +71,7 @@ fail_buf:
return ret;
}
int perf_trace_enable(int event_id)
int perf_trace_enable(int event_id, void *data)
{
struct ftrace_event_call *event;
int ret = -EINVAL;
@@ -77,7 +80,7 @@ int perf_trace_enable(int event_id)
list_for_each_entry(event, &ftrace_events, list) {
if (event->id == event_id && event->perf_event_enable &&
try_module_get(event->mod)) {
ret = perf_trace_event_enable(event);
ret = perf_trace_event_enable(event, data);
break;
}
}