tracing/filter: Remove synchronize_sched() from __alloc_preds()

Because the filters are processed first and then activated
(added to the call), we no longer need to worry about the preds
of the filter in __alloc_preds() being used. As the filter that
is allocating preds is not activated yet.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f5d335d..3249b4f 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -795,33 +795,17 @@ static int __alloc_preds(struct event_filter *filter, int n_preds)
        struct filter_pred *pred;
        int i;
 
-       if (filter->preds) {
-               if (filter->a_preds < n_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.
-                        */
-                       if (WARN_ON_ONCE(filter->n_preds)) {
-                               /* We need to reset it now */
-                               filter->n_preds = 0;
-                               synchronize_sched();
-                       }
-                       __free_preds(filter);
-               }
-       }
+       if (filter->preds)
+               __free_preds(filter);
+
+       filter->preds =
+               kzalloc(sizeof(*filter->preds) * n_preds, GFP_KERNEL);
 
-       if (!filter->preds) {
-               filter->preds =
-                       kzalloc(sizeof(*filter->preds) * n_preds, GFP_KERNEL);
-               filter->a_preds = n_preds;
-       }
        if (!filter->preds)
                return -ENOMEM;
 
-       if (WARN_ON(filter->a_preds < n_preds))
-               return -EINVAL;
+       filter->a_preds = n_preds;
+       filter->n_preds = 0;
 
        for (i = 0; i < n_preds; i++) {
                pred = &filter->preds[i];