From patchwork Fri Jul 7 17:21:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Valentin Schneider X-Patchwork-Id: 13305132 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 AC934EB64DA for ; Fri, 7 Jul 2023 17:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232699AbjGGRYG (ORCPT ); Fri, 7 Jul 2023 13:24:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232747AbjGGRXu (ORCPT ); Fri, 7 Jul 2023 13:23:50 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 801792685 for ; Fri, 7 Jul 2023 10:22:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688750545; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=07XsHvqnmvZKa7o2IK/zebs5uLAhltI+FwSlNCiWefo=; b=CFo8gUiBA8NbpA4kO9pls7atKlFMmiEULa7o4Kr1YlVt23BkFuoffAfeyiisaymhP5yZ8X nhHTleIkBJdUOkNHJCME2HO988BYgG3mCde3OLPZenZvJiBdPy9OYBXa3jpn8LEIMOP/lc Xmmw9q4Qk/RJIKgHnjiFjKwfcEmmUo8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-482-T692DJ9FPqK6du0vkEWOmw-1; Fri, 07 Jul 2023 13:22:22 -0400 X-MC-Unique: T692DJ9FPqK6du0vkEWOmw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 119CB185A794; Fri, 7 Jul 2023 17:22:22 +0000 (UTC) Received: from vschneid.remote.csb (unknown [10.42.28.164]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B97211454142; Fri, 7 Jul 2023 17:22:20 +0000 (UTC) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org Cc: Steven Rostedt , Masami Hiramatsu , Jonathan Corbet , Juri Lelli , Daniel Bristot de Oliveira , Marcelo Tosatti , Leonardo Bras , Frederic Weisbecker Subject: [PATCH v2 5/9] tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU Date: Fri, 7 Jul 2023 18:21:51 +0100 Message-Id: <20230707172155.70873-6-vschneid@redhat.com> In-Reply-To: <20230707172155.70873-1-vschneid@redhat.com> References: <20230707172155.70873-1-vschneid@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org 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. Suggested-by: Steven Rostedt Signed-off-by: Valentin Schneider --- 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 3009d0c61b532..2fe65ddeb34ef 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 *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 {