Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.
When the mask contains a single CPU, directly re-use the unsigned field
predicate functions. Transform '&' into '==' beforehand.
Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
---
kernel/trace/trace_events_filter.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 2fe65ddeb34ef..54d642fabb7f1 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1750,7 +1750,7 @@ static int parse_pred(const char *str, void *data,
* then we can treat it as a scalar input.
*/
single = cpumask_weight(pred->mask) == 1;
- if (single && field->filter_type == FILTER_CPUMASK) {
+ if (single && field->filter_type != FILTER_CPU) {
pred->val = cpumask_first(pred->mask);
kfree(pred->mask);
}
@@ -1761,6 +1761,11 @@ static int parse_pred(const char *str, void *data,
FILTER_PRED_FN_CPUMASK;
} else if (field->filter_type == FILTER_CPU) {
pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
+ } else if (single) {
+ pred->op = pred->op == OP_BAND ? OP_EQ : pred->op;
+ pred->fn_num = select_comparison_fn(pred->op, field->size, false);
+ if (pred->op == OP_NE)
+ pred->not = 1;
} else {
switch (field->size) {
case 8:
--
2.31.1
