From nobody Thu Dec 18 06:14:28 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 455B9EE49AB for ; Thu, 24 Aug 2023 02:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239388AbjHXCTR (ORCPT ); Wed, 23 Aug 2023 22:19:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239303AbjHXCSe (ORCPT ); Wed, 23 Aug 2023 22:18:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4842BE6D for ; Wed, 23 Aug 2023 19:18:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8D73F651F5 for ; Thu, 24 Aug 2023 02:18:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0A9AC433C9; Thu, 24 Aug 2023 02:18:30 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qYzvv-001hSK-1i; Wed, 23 Aug 2023 22:18:51 -0400 Message-ID: <20230824021851.347395220@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 23 Aug 2023 22:18:17 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , Jonathan Corbet , Juri Lelli , Daniel Bristot de Oliveira , Marcelo Tosatti , Leonardo Bras , Frederic Weisbecker , Valentin Schneider Subject: [for-next][PATCH 05/14] tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU References: <20230824021812.938245293@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Valentin Schneider 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 Cc: Jonathan Corbet Cc: Juri Lelli Cc: Daniel Bristot de Oliveira Cc: Marcelo Tosatti Cc: Leonardo Bras Cc: Frederic Weisbecker Suggested-by: Steven Rostedt Signed-off-by: Valentin Schneider Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_filter.c | 35 +++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events= _filter.c index 3009d0c61b53..2fe65ddeb34e 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -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 *pre= d, void *event) return do_filter_cpumask(pred->op, mask, cmp); } =20 +/* Filter predicate for cpumask field vs user-provided scalar */ +static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event) +{ + u32 item =3D *(u32 *)(event + pred->offset); + int loc =3D item & 0xffff; + const struct cpumask *mask =3D (event + loc); + unsigned int cpu =3D 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 *pr= ed, 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, =20 } else if (!strncmp(str + i, "CPUS", 4)) { unsigned int maskstart; + bool single; char *tmp; =20 switch (field->filter_type) { @@ -1724,8 +1744,21 @@ static int parse_pred(const char *str, void *data, =20 /* Move along */ i++; + + /* + * Optimisation: if the user-provided mask has a weight of one + * then we can treat it as a scalar input. + */ + single =3D cpumask_weight(pred->mask) =3D=3D 1; + if (single && field->filter_type =3D=3D FILTER_CPUMASK) { + pred->val =3D cpumask_first(pred->mask); + kfree(pred->mask); + } + if (field->filter_type =3D=3D FILTER_CPUMASK) { - pred->fn_num =3D FILTER_PRED_FN_CPUMASK; + pred->fn_num =3D single ? + FILTER_PRED_FN_CPUMASK_CPU : + FILTER_PRED_FN_CPUMASK; } else if (field->filter_type =3D=3D FILTER_CPU) { pred->fn_num =3D FILTER_PRED_FN_CPU_CPUMASK; } else { --=20 2.40.1