Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-10-23 13:40:56 +00:00
Code Issues Packages Projects Releases Wiki Activity

tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU

Browse Source 
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.

Reuse do_filter_scalar_cpumask() when the input mask has a weight of one.

Link: https://lkml.kernel.org/r/20230707172155.70873-6-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>
This commit is contained in:
Valentin Schneider 2023-07-07 18:21:51 +01:00 committed by Steven Rostedt (Google)
parent 347d24fc82
commit fe4fa4ec9b
1 changed files with 34 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
kernel/trace/trace_events_filter.c
View File

@ -70,6 +70,7 @@ enum filter_pred_fn {
FILTER_PRED_FN_CPU,
FILTER_PRED_FN_CPU_CPUMASK,
FILTER_PRED_FN_CPUMASK,
FILTER_PRED_FN_CPUMASK_CPU,
FILTER_PRED_FN_FUNCTION,
FILTER_PRED_FN_,
FILTER_PRED_TEST_VISITED,
@ -957,6 +958,22 @@ static int filter_pred_cpumask(struct filter_pred *pred, void *event)
return do_filter_cpumask(pred->op, mask, cmp);
}
/* Filter predicate for cpumask field vs user-provided scalar */
static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event)
{
u32 item = *(u32 *)(event + pred->offset);
int loc = item & 0xffff;
const struct cpumask *mask = (event + loc);
unsigned int cpu = pred->val;
/*
* This inverts the usual usage of the function (field is first element,
* user parameter is second), but that's fine because the (scalar, mask)
* operations used are symmetric.
*/
return do_filter_scalar_cpumask(pred->op, cpu, mask);
}
/* Filter predicate for COMM. */
static int filter_pred_comm(struct filter_pred *pred, void *event)
{
@ -1453,6 +1470,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
return filter_pred_cpu_cpumask(pred, event);
case FILTER_PRED_FN_CPUMASK:
return filter_pred_cpumask(pred, event);
case FILTER_PRED_FN_CPUMASK_CPU:
return filter_pred_cpumask_cpu(pred, event);
case FILTER_PRED_FN_FUNCTION:
return filter_pred_function(pred, event);
case FILTER_PRED_TEST_VISITED:
@ -1666,6 +1685,7 @@ static int parse_pred(const char *str, void *data,
} else if (!strncmp(str + i, "CPUS", 4)) {
unsigned int maskstart;
bool single;
char *tmp;
switch (field->filter_type) {
@ -1724,8 +1744,21 @@ static int parse_pred(const char *str, void *data,
/* Move along */
i++;
/*
* Optimisation: if the user-provided mask has a weight of one
* then we can treat it as a scalar input.
*/
single = cpumask_weight(pred->mask) == 1;
if (single && field->filter_type == FILTER_CPUMASK) {
pred->val = cpumask_first(pred->mask);
kfree(pred->mask);
}
if (field->filter_type == FILTER_CPUMASK) {
pred->fn_num = FILTER_PRED_FN_CPUMASK;
pred->fn_num = single ?
FILTER_PRED_FN_CPUMASK_CPU :
FILTER_PRED_FN_CPUMASK;
} else if (field->filter_type == FILTER_CPU) {
pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
} else {