From patchwork Wed Oct 27 20:59:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kalesh Singh X-Patchwork-Id: 12588077 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 A905DC433EF for ; Wed, 27 Oct 2021 21:00:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 823F760EFE for ; Wed, 27 Oct 2021 21:00:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239220AbhJ0VCZ (ORCPT ); Wed, 27 Oct 2021 17:02:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238798AbhJ0VCZ (ORCPT ); Wed, 27 Oct 2021 17:02:25 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AD02C061745 for ; Wed, 27 Oct 2021 13:59:59 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id v14-20020a05620a0f0e00b0043355ed67d1so2531316qkl.7 for ; Wed, 27 Oct 2021 13:59:59 -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=0GIbMz2nXytWEz1I//ilSEDA+vtJktC6KJwGcIeR3HQ=; b=WqC05lhqiNrvpuMTIPv4xuxZe1CYBGBTK/Dju6//MpTCOO3cE9JTJQS8+4MSbiH4ne fF+WTJ6eQ9HYI08zSQQERMu3qFzou499RsN2dcG97QC3ryg+rstVgT3ac+cAOsJo4t6/ fkQ24AbgXBerzeKy1TLX2fSKIjhvUQ05W7ZlSsC2YzKBhwuEikTYo65yhsIJW/OIkznQ CwzQP2KjtCDpEQp8Q7JIwoNjguJJDnLF1tnyuR51QARzXnltts3q4KvHf3LUxt1Z2Yl1 OjHoZEoaw+Mah+eIxDsaxViRL2GifZNf6GUL75xKTN2ftJ+9L4mrz7zsxADz6UnoSgV5 GytA== 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=0GIbMz2nXytWEz1I//ilSEDA+vtJktC6KJwGcIeR3HQ=; b=TwKjA5sbVNLZd8XUJGH0QPvlqdQiH5BbG2hHVJccAXjVYpBULkVIdhO6uUHTUM3aCD RHlAhFSE5nTnEbLs2H+6BOt4agDUcwFLa6/4YRgtPj1VQ1ZDPa8UfF+IKMmEAXdgmwTO DY001d2FRViDA4nWNkvDYl9XqqcpJy2rV/O4vx39WEYDgjB9HDHCdJCxn2aKsNXhFqEV CzDPUj5Fztu86nQr5ixxI96RpozZ0e8Py2k6842/o5o1DpN79NMVFZexepxaHeyyqKp4 FW1QBPcpty0hOCf+X3yUdwl5gC7jjX/JBlMmPZi0YV3zKpuhqA2Ti2XP4cuqkbFw6yj4 SXqg== X-Gm-Message-State: AOAM530fDx+YYzLbRW3ql9L0BfjhvtYwnY1wfdoPi3hh8NWxc2klzLLq H/lUJfdsOHXK0sFAy9S4Z8lCM4wUj9qK/7J10Q== X-Google-Smtp-Source: ABdhPJxDwW2S7YdUya+jCM5lkK9C0VdJjk4Vq1uieuMPS+sXbR9F9YxF+rPyacRwAxu4kvLVzDCY1qBTzybkFJvdvw== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:ac51:b6be:9b51:3a7c]) (user=kaleshsingh job=sendgmr) by 2002:a05:622a:50a:: with SMTP id l10mr127848qtx.73.1635368398653; Wed, 27 Oct 2021 13:59:58 -0700 (PDT) Date: Wed, 27 Oct 2021 13:59:08 -0700 In-Reply-To: <20211027205919.1648553-1-kaleshsingh@google.com> Message-Id: <20211027205919.1648553-2-kaleshsingh@google.com> Mime-Version: 1.0 References: <20211027205919.1648553-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.33.0.1079.g6e70778dc9-goog Subject: [PATCH 1/3] 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 , Ingo Molnar , Shuah Khan , 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 --- 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"