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tracing/filters: Further optimise scalar vs cpumask comparison

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Per the previous commits, we now only enter do_filter_scalar_cpumask() with
a mask of weight greater than one. Optimise the equality checks.

Link: https://lkml.kernel.org/r/20230707172155.70873-9-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 18:21:54 +01:00 committed by Steven Rostedt (Google)
parent 1cffbe6c62
commit 38c6f68083
1 changed files with 20 additions and 6 deletions
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26
kernel/trace/trace_events_filter.c
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@ -667,6 +667,25 @@ do_filter_cpumask(int op, const struct cpumask *mask, const struct cpumask *cmp)
/* Optimisation of do_filter_cpumask() for scalar fields */
static inline int
do_filter_scalar_cpumask(int op, unsigned int cpu, const struct cpumask *mask)
{
/*
* Per the weight-of-one cpumask optimisations, the mask passed in this
* function has a weight >= 2, so it is never equal to a single scalar.
*/
switch (op) {
case OP_EQ:
return false;
case OP_NE:
return true;
case OP_BAND:
return cpumask_test_cpu(cpu, mask);
default:
return 0;
}
}
static inline int
do_filter_cpumask_scalar(int op, const struct cpumask *mask, unsigned int cpu)
{
switch (op) {
case OP_EQ:
@ -966,12 +985,7 @@ static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event)
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);
return do_filter_cpumask_scalar(pred->op, mask, cpu);
}
/* Filter predicate for COMM. */