[PATCH 12/21] tracing/filter: Change filter_match_preds function to use

Steven Rostedt
2011-09-22T22:12:37Z

[-- Attachment #1: 0012-tracing-filter-Change-filter_match_preds-function-to.patch walk_pred_tree --]
[-- Type: text/plain, Size: 4481 bytes --]

From: Jiri Olsa <jolsa@redhat.com>

Changing filter_match_preds function to use unified predicates tree
processing.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1313072754-4620-10-git-send-email-jolsa@redhat.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 124 +++++++++++++++++-------------------
1 files changed, 58 insertions(+), 66 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f44e68b..319c3ca 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -467,99 +467,91 @@ static int process_ops(struct filter_pred *preds,

for (i = 0; i < op->val; i++) {
pred = &preds[op->ops[i]];
- match = pred->fn(pred, rec);
+ if (!WARN_ON_ONCE(!pred->fn))
+ match = pred->fn(pred, rec);
if (!!match == type)
return match;
}
return match;
}

+struct filter_match_preds_data {
+ struct filter_pred *preds;
+ int match;
+ void *rec;
+};
+
+static int filter_match_preds_cb(enum move_type move, struct filter_pred *pred,
+ int *err, void *data)
+{
+ struct filter_match_preds_data *d = data;
+
+ *err = 0;
+ switch (move) {
+ case MOVE_DOWN:
+ /* only AND and OR have children */
+ if (pred->left != FILTER_PRED_INVALID) {
+ /* If ops is set, then it was folded. */
+ if (!pred->ops)
+ return WALK_PRED_DEFAULT;
+ /* We can treat folded ops as a leaf node */
+ d->match = process_ops(d->preds, pred, d->rec);
+ } else {
+ if (!WARN_ON_ONCE(!pred->fn))
+ d->match = pred->fn(pred, d->rec);
+ }
+
+ return WALK_PRED_PARENT;
+ case MOVE_UP_FROM_LEFT:
+ /*
+ * Check for short circuits.
+ *
+ * Optimization: !!match == (pred->op == OP_OR)
+ * is the same as:
+ * if ((match && pred->op == OP_OR) ||
+ * (!match && pred->op == OP_AND))
+ */
+ if (!!d->match == (pred->op == OP_OR))
+ return WALK_PRED_PARENT;
+ break;
+ case MOVE_UP_FROM_RIGHT:
+ break;
+ }
+
+ return WALK_PRED_DEFAULT;
+}
+
/* return 1 if event matches, 0 otherwise (discard) */
int filter_match_preds(struct event_filter *filter, void *rec)
{
- int match = -1;
- enum move_type move = MOVE_DOWN;
struct filter_pred *preds;
- struct filter_pred *pred;
struct filter_pred *root;
- int n_preds;
- int done = 0;
+ struct filter_match_preds_data data = {
+ /* match is currently meaningless */
+ .match = -1,
+ .rec = rec,
+ };
+ int n_preds, ret;

/* no filter is considered a match */
if (!filter)
return 1;

n_preds = filter->n_preds;
-
if (!n_preds)
return 1;

/*
* n_preds, root and filter->preds are protect with preemption disabled.
*/
- preds = rcu_dereference_sched(filter->preds);
root = rcu_dereference_sched(filter->root);
if (!root)
return 1;

- pred = root;
-
- /* match is currently meaningless */
- match = -1;
-
- do {
- switch (move) {
- case MOVE_DOWN:
- /* only AND and OR have children */
- if (pred->left != FILTER_PRED_INVALID) {
- /* If ops is set, then it was folded. */
- if (!pred->ops) {
- /* keep going to down the left side */
- pred = &preds[pred->left];
- continue;
- }
- /* We can treat folded ops as a leaf node */
- match = process_ops(preds, pred, rec);
- } else
- match = pred->fn(pred, rec);
- /* If this pred is the only pred */
- if (pred == root)
- break;
- pred = get_pred_parent(pred, preds,
- pred->parent, &move);
- continue;
- case MOVE_UP_FROM_LEFT:
- /*
- * Check for short circuits.
- *
- * Optimization: !!match == (pred->op == OP_OR)
- * is the same as:
- * if ((match && pred->op == OP_OR) ||
- * (!match && pred->op == OP_AND))
- */
- if (!!match == (pred->op == OP_OR)) {
- if (pred == root)
- break;
- pred = get_pred_parent(pred, preds,
- pred->parent, &move);
- continue;
- }
- /* now go down the right side of the tree. */
- pred = &preds[pred->right];
- move = MOVE_DOWN;
- continue;
- case MOVE_UP_FROM_RIGHT:
- /* We finished this equation. */
- if (pred == root)
- break;
- pred = get_pred_parent(pred, preds,
- pred->parent, &move);
- continue;
- }
- done = 1;
- } while (!done);
-
- return match;
+ data.preds = preds = rcu_dereference_sched(filter->preds);
+ ret = walk_pred_tree(preds, root, filter_match_preds_cb, &data);
+ WARN_ON(ret);
+ return data.match;
}
EXPORT_SYMBOL_GPL(filter_match_preds);

--
1.7.5.4