Commit 38c6f680 authored by Valentin Schneider's avatar Valentin Schneider Committed by Steven Rostedt (Google)
Browse files

tracing/filters: Further optimise scalar vs cpumask comparison 

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: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarValentin Schneider <vschneid@redhat.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 1cffbe6c

kernel/trace/trace_events_filter.c

+20 −6
Original line number Diff line number Diff line
@@ -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. */