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authorValentin Schneider <vschneid@redhat.com>2023-07-07 18:21:52 +0100
committerSteven Rostedt (Google) <rostedt@goodmis.org>2023-08-22 05:13:29 -0400
commitca77dd8ce4658d1006d747dd1995ebb9375199c8 (patch)
treefe3e688acd19ee93bea4bbf1ea2585c8446dddbb
parentfe4fa4ec9b464f5a93b2010247822fdd3a2a2115 (diff)
tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU
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. Link: https://lkml.kernel.org/r/20230707172155.70873-7-vschneid@redhat.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Leonardo Bras <leobras@redhat.com> Cc: Frederic Weisbecker <frederic@kernel.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_events_filter.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 2fe65ddeb34e..54d642fabb7f 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: