Commit-ID: 0fc3ca9a10a61a77f18710fb708b41fd99c79a56
Gitweb: http://git.kernel.org/tip/0fc3ca9a10a61a77f18710fb708b41fd99c79a56
Author: Steven Rostedt <srostedt@xxxxxxxxxx>
AuthorDate: Thu, 27 Jan 2011 22:46:46 -0500
Committer: Steven Rostedt <rostedt@xxxxxxxxxxx>
CommitDate: Mon, 7 Feb 2011 20:56:18 -0500
tracing/filter: Call synchronize_sched() just once for system filters
By separating out the reseting of the filter->n_preds to zero from
the reallocation of preds for the filter, we can reset groups of
filters first, call synchronize_sched() just once, and then reallocate
each of the filters in the system group.
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_events_filter.c | 80 ++++++++++++++++++++++++++++--------
1 files changed, 63 insertions(+), 17 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index aac6a61..8f00a11 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -570,17 +570,28 @@ static void __free_preds(struct event_filter *filter)
filter->n_preds = 0;
}
+static void reset_preds(struct event_filter *filter)
+{
+ struct filter_pred *pred;
+ int n_preds = filter->n_preds;
+ int i;
+
+ filter->n_preds = 0;
+ if (!filter->preds)
+ return;
+
+ for (i = 0; i < n_preds; i++) {
+ pred = filter->preds[i];
+ pred->fn = filter_pred_none;
+ }
+}
+
static void filter_disable_preds(struct ftrace_event_call *call)
{
struct event_filter *filter = call->filter;
- int i;
call->flags &= ~TRACE_EVENT_FL_FILTERED;
- if (filter->preds) {
- for (i = 0; i < filter->n_preds; i++)
- filter->preds[i]->fn = filter_pred_none;
- }
- filter->n_preds = 0;
+ reset_preds(filter);
}
static void __free_filter(struct event_filter *filter)
@@ -620,15 +631,17 @@ static int __alloc_preds(struct event_filter *filter, int n_preds)
if (filter->preds) {
if (filter->a_preds < n_preds) {
- /* We need to reallocate */
- filter->n_preds = 0;
/*
- * It is possible that the filter is currently
- * being used. We need to zero out the number
- * of preds, wait on preemption and then free
- * the preds.
+ * We need to reallocate.
+ * We should have already have zeroed out
+ * the pred count and called synchronized_sched()
+ * to make sure no one is using the preds.
*/
- synchronize_sched();
+ if (WARN_ON_ONCE(filter->n_preds)) {
+ /* We need to reset it now */
+ filter->n_preds = 0;
+ synchronize_sched();
+ }
__free_preds(filter);
}
}
@@ -1328,6 +1341,30 @@ static int replace_system_preds(struct event_subsystem *system,
/* try to see if the filter can be applied */
err = replace_preds(call, filter, ps, filter_string, true);
if (err)
+ goto fail;
+ }
+
+ /* set all filter pred counts to zero */
+ list_for_each_entry(call, &ftrace_events, list) {
+ struct event_filter *filter = call->filter;
+
+ if (strcmp(call->class->system, system->name) != 0)
+ continue;
+
+ reset_preds(filter);
+ }
+
+ /*
+ * Since some of the preds may be used under preemption
+ * we need to wait for them to finish before we may
+ * reallocate them.
+ */
+ synchronize_sched();
+
+ list_for_each_entry(call, &ftrace_events, list) {
+ struct event_filter *filter = call->filter;
+
+ if (strcmp(call->class->system, system->name) != 0)
continue;
/* really apply the filter */
@@ -1342,11 +1379,13 @@ static int replace_system_preds(struct event_subsystem *system,
fail = false;
}
- if (fail) {
- parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
- return -EINVAL;
- }
+ if (fail)
+ goto fail;
+
return 0;
+ fail:
+ parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ return -EINVAL;
}
int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
@@ -1381,6 +1420,13 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
goto out;
}
+ /*
+ * Make sure all the pred counts are zero so that
+ * no task is using it when we reallocate the preds array.
+ */
+ reset_preds(call->filter);
+ synchronize_sched();
+
err = replace_preds(call, call->filter, ps, filter_string, false);
if (err)
append_filter_err(ps, call->filter);
--
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