From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED37EC433F5 for ; Wed, 15 Sep 2021 19:56:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5F6E61056 for ; Wed, 15 Sep 2021 19:56:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230451AbhIOT53 (ORCPT ); Wed, 15 Sep 2021 15:57:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229732AbhIOT52 (ORCPT ); Wed, 15 Sep 2021 15:57:28 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDE63C061574 for ; Wed, 15 Sep 2021 12:56:08 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id ci14-20020a056214054e00b0037a75ff56f9so7919470qvb.23 for ; Wed, 15 Sep 2021 12:56:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:cc; bh=1D42zcUJP7Yd1OBpScfym6RyYgwjdXqxQ6ExRKg2hiA=; b=Qh0v9EKYh48K68psvZw/Otnu1Zajri6jZtVWAmAzRMbjKkXMNn7aUytL84TkGc35Zi jQkaUW8s37BO+r9+CjdYmuoh7FtOt1xKAj8a1JzrU3AwROGOoFkD8kB6uemU5my+CBSO 0OL2auP8TMx/9JFv4TCUyGCUqlM7LRyrHLCDbLHqtr+LLHQvR35GljwU1glAgjF0S83c wEoOzRecOUU9v83n0SU2CvxBeDGyTpjnoGaT/ZxSz5gXOEMEpq87pPp5df5kR6VR8dnt XyGdFE3sQ8LTIgxkHbltYDGsQ7scPikxhX1P8WIz5ihyIriym9+y4KmX/yrWgllYIoYC vjrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:cc; bh=1D42zcUJP7Yd1OBpScfym6RyYgwjdXqxQ6ExRKg2hiA=; b=ytkfZ5Cb8Z5fc/xN1vmRFCSk9BO3TMLciuOwj9uXc+GjxvyRM+mqKKujXxeGhBDSan 2zSi7mzPM8pI9KA8CJSkNHHle1pK74pqRbezfvsN/6jbBoD9h2LuHH7PwIQjKAsatxm2 f38Md240+yRbrCr9agFhfVu5A+pNu1pM379FJ6OQk8kFWZBI7B9wim/GThzIOMd8O91Z EFDS9Q+c11Nf5IwX1gwbLEuF+CZW7hAlfPKWUiPRoTgq/rOB0tQ72h8cbebRgyAM12dW AC7AM6F8r5eQz8pTL/grLFvVk/docG6JMPrOhr0rV0NdBYEE28Wh1Zz5MyTHna4pk+Pz 7hLg== X-Gm-Message-State: AOAM533STyRKT6AErv31tOctieP9hkqy7dvxcHqL+DZYfgdEEv1DtWHY VwZZwaoVgUiNumEu6OzaEURRlhIzy9Dq4gLbig== X-Google-Smtp-Source: ABdhPJwstirmxKy545qmG+7yGZJ8nD+HM/bCVTLS993GeQPljENqko1YZQK4YfHdcV2F9a4mLCkNhctIjasPMFiD3w== X-Received: from kaleshsingh.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2145]) (user=kaleshsingh job=sendgmr) by 2002:a05:6214:1142:: with SMTP id b2mr1799508qvt.0.1631735768059; Wed, 15 Sep 2021 12:56:08 -0700 (PDT) Date: Wed, 15 Sep 2021 19:52:49 +0000 In-Reply-To: <20210915195306.612966-1-kaleshsingh@google.com> Message-Id: <20210915195306.612966-6-kaleshsingh@google.com> Mime-Version: 1.0 References: <20210915195306.612966-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.33.0.309.g3052b89438-goog Subject: [PATCH 5/5] tracing/histogram: Document expression arithmetic and constants From: Kalesh Singh Cc: surenb@google.com, hridya@google.com, namhyung@kernel.org, Kalesh Singh , Jonathan Corbet , Steven Rostedt , Ingo Molnar , Shuah Khan , Masami Hiramatsu , Tom Zanussi , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Histogram expressions now support division, and multiplication in addition to the already supported subtraction and addition operators. Numeric constants can also be used in a hist trigger expressions or assigned to a variable and used by refernce in an expression. Signed-off-by: Kalesh Singh --- Documentation/trace/histogram.rst | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst index 533415644c54..e12699abaee8 100644 --- a/Documentation/trace/histogram.rst +++ b/Documentation/trace/histogram.rst @@ -1763,6 +1763,20 @@ using the same key and variable from yet another event:: # echo 'hist:key=pid:wakeupswitch_lat=$wakeup_lat+$switchtime_lat ...' >> event3/trigger +Expressions support the use of addition, subtraction, multiplication and +division operators (+-*/). + +Note that division by zero always returns -1. + +Numeric constants can also be used directly in an expression:: + + # echo 'hist:keys=next_pid:timestamp_secs=common_timestamp/1000000 ...' >> event/trigger + +or assigned to a variable and referenced in a subsequent expression:: + + # echo 'hist:keys=next_pid:us_per_sec=1000000 ...' >> event/trigger + # echo 'hist:keys=next_pid:timestamp_secs=common_timestamp/$us_per_sec ...' >> event/trigger + 2.2.2 Synthetic Events ---------------------- -- 2.33.0.309.g3052b89438-goog