| Message ID | 20230720163056.2564824-7-vschneid@redhat.com |
|---|---|
| State | Accepted |
| Commit | ca77dd8ce4658d1006d747dd1995ebb9375199c8 |
| Headers | show |
| Series | context_tracking,x86: Defer some IPIs until a user->kernel transition | expand |
On Thu, 20 Jul 2023 17:30:42 +0100 Valentin Schneider <vschneid@redhat.com> wrote: > 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@goodmis.org> > Signed-off-by: Valentin Schneider <vschneid@redhat.com> > --- > 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; Nit, the above can be written as: pred->op = pret->op != OP_BAND ? : OP_EQ; -- Steve > + 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:
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:
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@goodmis.org> Signed-off-by: Valentin Schneider <vschneid@redhat.com> --- kernel/trace/trace_events_filter.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)