From c142b15dc56ee6d55cb97a062e3c8e9c61e384c0 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 8 May 2009 10:32:05 +0800 Subject: [PATCH] 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 Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker LKML-Reference: <4A0399A5.2080603@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_events.c | 40 ++++++------------------------------- 1 file 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 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { + const char set_to_char[4] = { '?', '0', '1', 'X' }; const char *system = filp->private_data; struct ftrace_event_call *call; char buf[2]; - int set = -1; + int set = 0; int ret; mutex_lock(&event_mutex); @@ -433,47 +434,18 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, * or if all events or cleared, or if we have * a mixture. */ - if (call->enabled) { - switch (set) { - case -1: - set = 1; - break; - case 0: - set = 2; - break; - } - } else { - switch (set) { - case -1: - set = 0; - break; - case 1: - set = 2; - break; - } - } + set |= (1 << !!call->enabled); + /* * If we have a mixture, no need to look further. */ - if (set == 2) + if (set == 3) break; } mutex_unlock(&event_mutex); + buf[0] = set_to_char[set]; buf[1] = '\n'; - switch (set) { - case 0: - buf[0] = '0'; - break; - case 1: - buf[0] = '1'; - break; - case 2: - buf[0] = 'X'; - break; - default: - buf[0] = '?'; - } ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); -- GitLab