diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2010-04-23 11:12:36 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-05-14 14:33:22 -0400 |
| commit | 553552ce1796c32cf4e3d4f45cd5b537de91dd1d (patch) | |
| tree | a65defc1055bcc3e9f34327d2cc59704e536948b /kernel/trace/trace_events.c | |
| parent | 32c0edaeaad74a7883e736ae0f3798784cfc2a80 (diff) | |
tracing: Combine event filter_active and enable into single flags field
The filter_active and enable both use an int (4 bytes each) to
set a single flag. We can save 4 bytes per event by combining the
two into a single integer.
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4894944 1018052 861512 6774508 675eec vmlinux.id
4894871 1012292 861512 6768675 674823 vmlinux.flags
This gives us another 5K in savings.
The modification of both the enable and filter fields are done
under the event_mutex, so it is still safe to combine the two.
Note: Although Mathieu gave his Acked-by, he would like it documented
that the reads of flags are not protected by the mutex. The way the
code works, these reads will not break anything, but will have a
residual effect. Since this behavior is the same even before this
patch, describing this situation is left to another patch, as this
patch does not change the behavior, but just brought it to Mathieu's
attention.
v2: Updated the event trace self test to for this change.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 8daaca5475b..53cffc0b080 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -137,8 +137,8 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call, switch (enable) { case 0: - if (call->enabled) { - call->enabled = 0; + if (call->flags & TRACE_EVENT_FL_ENABLED) { + call->flags &= ~TRACE_EVENT_FL_ENABLED; tracing_stop_cmdline_record(); if (call->class->reg) call->class->reg(call, TRACE_REG_UNREGISTER); @@ -149,7 +149,7 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call, } break; case 1: - if (!call->enabled) { + if (!(call->flags & TRACE_EVENT_FL_ENABLED)) { tracing_start_cmdline_record(); if (call->class->reg) ret = call->class->reg(call, TRACE_REG_REGISTER); @@ -163,7 +163,7 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call, "%s\n", call->name); break; } - call->enabled = 1; + call->flags |= TRACE_EVENT_FL_ENABLED; } break; } @@ -352,7 +352,7 @@ s_next(struct seq_file *m, void *v, loff_t *pos) (*pos)++; list_for_each_entry_continue(call, &ftrace_events, list) { - if (call->enabled) + if (call->flags & TRACE_EVENT_FL_ENABLED) return call; } @@ -411,7 +411,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, struct ftrace_event_call *call = filp->private_data; char *buf; - if (call->enabled) + if (call->flags & TRACE_EVENT_FL_ENABLED) buf = "1\n"; else buf = "0\n"; @@ -486,7 +486,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, * or if all events or cleared, or if we have * a mixture. */ - set |= (1 << !!call->enabled); + set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED)); /* * If we have a mixture, no need to look further. @@ -1447,7 +1447,7 @@ static __init void event_trace_self_tests(void) * If an event is already enabled, someone is using * it and the self test should not be on. */ - if (call->enabled) { + if (call->flags & TRACE_EVENT_FL_ENABLED) { pr_warning("Enabled event during self test!\n"); WARN_ON_ONCE(1); continue; |