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authorLi Zefan <lizf@cn.fujitsu.com>2009-05-07 22:32:05 -0400
committerIngo Molnar <mingo@elte.hu>2009-05-08 08:00:36 -0400
commitc142b15dc56ee6d55cb97a062e3c8e9c61e384c0 (patch)
treed273ba8c5ce28bea224e4f48b9704e47ed68a2b4 /kernel/trace/trace_events.c
parent8f31bfe538ebafac187d2d4465a92e1d9ee6d8c2 (diff)
tracing/events: simplify system_enable_read()
A smarter way to figure out the output of an enable file. [ Impact: clean up ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A0399A5.2080603@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c40
1 files changed, 6 insertions, 34 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 45f1099386b6..df394bc6d54b 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -414,10 +414,11 @@ static ssize_t
414system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, 414system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
415 loff_t *ppos) 415 loff_t *ppos)
416{ 416{
417 const char set_to_char[4] = { '?', '0', '1', 'X' };
417 const char *system = filp->private_data; 418 const char *system = filp->private_data;
418 struct ftrace_event_call *call; 419 struct ftrace_event_call *call;
419 char buf[2]; 420 char buf[2];
420 int set = -1; 421 int set = 0;
421 int ret; 422 int ret;
422 423
423 mutex_lock(&event_mutex); 424 mutex_lock(&event_mutex);
@@ -433,47 +434,18 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
433 * or if all events or cleared, or if we have 434 * or if all events or cleared, or if we have
434 * a mixture. 435 * a mixture.
435 */ 436 */
436 if (call->enabled) { 437 set |= (1 << !!call->enabled);
437 switch (set) { 438
438 case -1:
439 set = 1;
440 break;
441 case 0:
442 set = 2;
443 break;
444 }
445 } else {
446 switch (set) {
447 case -1:
448 set = 0;
449 break;
450 case 1:
451 set = 2;
452 break;
453 }
454 }
455 /* 439 /*
456 * If we have a mixture, no need to look further. 440 * If we have a mixture, no need to look further.
457 */ 441 */
458 if (set == 2) 442 if (set == 3)
459 break; 443 break;
460 } 444 }
461 mutex_unlock(&event_mutex); 445 mutex_unlock(&event_mutex);
462 446
447 buf[0] = set_to_char[set];
463 buf[1] = '\n'; 448 buf[1] = '\n';
464 switch (set) {
465 case 0:
466 buf[0] = '0';
467 break;
468 case 1:
469 buf[0] = '1';
470 break;
471 case 2:
472 buf[0] = 'X';
473 break;
474 default:
475 buf[0] = '?';
476 }
477 449
478 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); 450 ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
479 451