From patchwork Fri Oct 29 18:33:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kalesh Singh X-Patchwork-Id: 12593265 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4738AC433FE for ; Fri, 29 Oct 2021 18:34:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F88461037 for ; Fri, 29 Oct 2021 18:34:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230177AbhJ2Sgx (ORCPT ); Fri, 29 Oct 2021 14:36:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230319AbhJ2Sgv (ORCPT ); Fri, 29 Oct 2021 14:36:51 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADF77C0613F5 for ; Fri, 29 Oct 2021 11:34:22 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id v7-20020a25ab87000000b005c2130838beso583026ybi.0 for ; Fri, 29 Oct 2021 11:34:22 -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=aWdu1dWgU6LDlQT9WUgK1tbGyRaKD3AurTsATcx1ByY=; b=jtbbuakJZsRZNaPCbKbfFEJmOU9Uoi3SgTKnPTxiKpMGfnbaSlJy2stcE7VXQOgk3Y 8bE9sTwZB4gVvZSs1w9ZbFbvJ0t1unK6DB/gzmQgkm6HgAOJEHv968FbY7hJajgtUNoY 2BCnTRP2ZgFqaTEimHnrN4cHb3FYJnJ5ib+SWRJpS11KIYfX42ZpP9gP+7ctok3m4WCi zz6X2fY2YHn7qSqq5hKQ864OD25HPN/N2P2WJ6otYalY28oNO4h/iToCmZhKd39P8xPU aAfSZLHDuo6WjfoAbCXaTjT1jVku5v4UJomfxT54+0kxQMfJyGQQcUeYWtUq28iBayuR PxpA== 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=aWdu1dWgU6LDlQT9WUgK1tbGyRaKD3AurTsATcx1ByY=; b=t/ao4wcwe5in9WdxShFB2koLF03WOEc35+mZQbCHLIHZjFy3gYBFa9sVBxg9cHyUb9 UnE2fSuPArADJHeDSCvcJZB0ZUjMehwnRHfGfw9cbwziBDzIcmw0wY+Qs5YPrLfxO1L6 Kb9SYIUso9wtIx7tdOpUEhwsEFXA0pDg1azT73VfKvkkmTwEJhnWcXPtb0ObqFaCtt14 B9bG5y7q2kj9istautyr5SKoXgfclM5NF8egSuez3I72ods12++y2GSMK2SFUf9CQe63 cW+GdxOcdA+lr+8xMbe2Aj9SM9UENGYoSQa8nlMOChFIsOYnaZrNQ3kBLe0yuoZjqnJ5 54iA== X-Gm-Message-State: AOAM531q9e5h/fdeRRRdW2ARhfjxl9fsenUB/1mZ2k3TH/3f4RXOBZwP 3+kzqd5ZiGS9l3T1Jv8fjpUA2Wgik0ZqA23sFg== X-Google-Smtp-Source: ABdhPJxoOcfzYFe02j1Yvr53Nxi/e0BJwqCy7bwvJ5kG7TNG3tF0RFNwZgGROz2u207zvd8NZcELsX/MmPmadoPPMw== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:b03:1d88:1cf2:4973]) (user=kaleshsingh job=sendgmr) by 2002:a5b:402:: with SMTP id m2mr13884785ybp.422.1635532461875; Fri, 29 Oct 2021 11:34:21 -0700 (PDT) Date: Fri, 29 Oct 2021 11:33:29 -0700 In-Reply-To: <20211029183339.3216491-1-kaleshsingh@google.com> Message-Id: <20211029183339.3216491-4-kaleshsingh@google.com> Mime-Version: 1.0 References: <20211029183339.3216491-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.33.1.1089.g2158813163f-goog Subject: [PATCH v3 3/4] tracing/histogram: Document hist trigger variables From: Kalesh Singh Cc: surenb@google.com, hridya@google.com, namhyung@kernel.org, kernel-team@android.com, rostedt@goodmis.org, mhiramat@kernel.org, Kalesh Singh , Jonathan Corbet , Ingo Molnar , Shuah Khan , Tom Zanussi , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Update the tracefs README to describe how hist trigger variables can be created. Signed-off-by: Kalesh Singh Acked-by: Masami Hiramatsu --- Changes in v2: - Add Masami's Acked-by. kernel/trace/trace.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bc677cd64224..c41b3786401d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5628,6 +5628,7 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=\n" + "\t [:=[,=...]]\n" "\t [:values=]\n" "\t [:sort=]\n" "\t [:size=#entries]\n" @@ -5639,6 +5640,16 @@ static const char readme_msg[] = "\t common_timestamp - to record current timestamp\n" "\t common_cpu - to record the CPU the event happened on\n" "\n" + "\t A hist trigger variable can be:\n" + "\t - a reference to a field e.g. x=current_timestamp,\n" + "\t - a reference to another variable e.g. y=$x,\n" + "\t - a numeric literal: e.g. ms_per_sec=1000,\n" + "\t - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n" + "\n" + "\t hist trigger aritmethic expressions support addition(+), subtraction(-),\n" + "\t multiplication(*) and division(/) operators. An operand can be either a\n" + "\t variable reference, field or numeric literal.\n" + "\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" "\t sum called 'hitcount' is incremented. Keys and values\n"