From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f171.google.com (mail-pf1-f171.google.com [209.85.210.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CFBE2DA77F for ; Tue, 16 Sep 2025 05:42:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758001348; cv=none; b=Hj6NIQ5t4X6VU1r2QWMQy9ztcSz8KYX1pfT9J9HAv/SvtsrOxxUkMMA789C10nSwBXZmJKAPg1tsTIFwXdtFv9BgAsoYU92iftLmgNVmib9W1CIxBij7RZQ92aJrsFAqJBX0Sg/8qVfROfCKd+ihB9bGbnFN3wfzDML8DMkwj08= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758001348; c=relaxed/simple; bh=iFycX2BAN7hX0KeER10Qq/N2vEd9PT/ZiaaR3gB9rS8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BTyajyjfpoXzElNchp+FhM2GpDP1FmpDWuZipsPtE4XiEni+KZ/WQyTop0pbngk4O+Je56vXcYMj3mElqy3AlhIf3RMWSVhnMZloyq4RbDLqXSYZ4++bjvJ8tKlPrHgRvxpbE/gTbcuer6Kih8BqnwLr9eLghevOR0+86ALjoFY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bsNFmpGu; arc=none smtp.client-ip=209.85.210.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bsNFmpGu" Received: by mail-pf1-f171.google.com with SMTP id d2e1a72fcca58-77256e75eacso4037234b3a.0 for ; Mon, 15 Sep 2025 22:42:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1758001345; x=1758606145; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Dzt8jm8JhxQa9RfhdOFYy8EQflQhajk0iYv+kw4cn4Y=; b=bsNFmpGuhpveB8vqd07bVKPNvhXh0l2DosaqQLnTylV0S5jwdoTxpNkcSrzpFAUdMm 5FiY7z4YHNNGjxtB8d/PjeYoSol3yYnW7OYDEV65Karn6shyE4xtTc9m6KRycE3cy3Ly w3m1Sx+qBkHuagV2Gzy/U33cfqw4aFzesuDhEYv3Dm6wHgGLDO8UKCIBx/qLAY0J8oLs G7kEHvdVhMhQO00jN6ZeIl4rl7uAbRMoyA2Pc5QnBfKeATzegTOTqxy+vMjOrehZEzIZ NzU3GEadBbTgS2fUm/uYLdHZQiHdCa3a+FZjrK6p5Pzytgr/DijgJwHkiW52XU66KSyY OnGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758001345; x=1758606145; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Dzt8jm8JhxQa9RfhdOFYy8EQflQhajk0iYv+kw4cn4Y=; b=HseWyRZ3LKSop0jO7HtsbhxauXq6bdwP32u4CQfwXx5a1QYc08b+dNe4I4rSETBWkK PPmQTnyf+7qUxp1FJb2WMMhE3Hn9X1prAhpBgentN8CmNMsGXzpkMZStz34gHbY7BTp3 EyxAvOy3tAJja/cD71SD6hgvdib66q299G9Cop8KjDtLp0u2CGs5dVGbHoQUnr7rcThq rKVFFE4bj9an2qyIC9QIOlpJFRS87JBYIS3JinNkx3sS9U9/Uo/M93y4MUSRx+iWVsWI 9tFI5ZYznQS3PxnAcwJOjDlokW/iszYnQCCwXfDWK78xvnpdQRo57zjYzEOGTDIOtqk4 PyJw== X-Forwarded-Encrypted: i=1; AJvYcCVLoAgv3IB7oVDcEL1nmiZsn5Oc4hUpp4Dq185ERi4uaTZC8XKZJZVf1sArpS0wp1Fd1zTRDT3SepY=@vger.kernel.org X-Gm-Message-State: AOJu0YyneFcf2OOL6Qi3eF5p6aqB47i04gXVXURKyci6HEFCqxbdcu5l 5DproPH5Li73VEdxTDN9cIi8aEkIE+8Brix3q62CujpnEBb6FxvBi5nx X-Gm-Gg: ASbGncvD0wBUjOZQ3KWJylZTvXv/qZtY19yvLx8fvEj5CsOsse7LP8M62jUKQdtY1Ju gBLUleypxjrZ+GD6jnxuD29D8ea9towbrkeDAt67BOxlowT2xROF9EaXTRzcMAZ9UTL+6R4nk35 aznPhuuDMV41+4Uql1h73zHIiDjHHFvi6THoZhhlsavlMdnRi0pbTU6D6NT+CQZ13Ta+jK18eAi HsTibm4u4tWIH65HQ65KcpTHZ8o4+YIVxtPos4CVdXNFcg5Znhl5U5gkqdsr+YN4Qp+kJvHWIyE t1Ppn6cx15Hn7bLcGJMCpEeVeJq/eEUc75XHvEHW8L16OcOUuCuxqOdkDZaEF5ICBfvDJ+cb8rf rtsX1r5yM0vVHvUhNTHyEOM95aQ== X-Google-Smtp-Source: AGHT+IERvIDfQ9i3bIonnATiSRpxkSuZxnxy4IiIBGBcwTK6cxHQPmYWEwl6AsIZqqsEIp8yGjYcmQ== X-Received: by 2002:a05:6a21:998e:b0:24a:b2eb:6675 with SMTP id adf61e73a8af0-2602a59332bmr18403353637.13.1758001345194; Mon, 15 Sep 2025 22:42:25 -0700 (PDT) Received: from archie.me ([103.124.138.155]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-b54dd63d5e5sm1155741a12.4.2025.09.15.22.42.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Sep 2025 22:42:23 -0700 (PDT) Received: by archie.me (Postfix, from userid 1000) id 27C9C41FA3A1; Tue, 16 Sep 2025 12:42:18 +0700 (WIB) From: Bagas Sanjaya To: Linux Kernel Mailing List , Linux Documentation , Linux Kernel Tracing Cc: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Tom Zanussi , Bagas Sanjaya Subject: [PATCH v2 1/5] Documentation: trace: histogram: Fix histogram trigger subsection number order Date: Tue, 16 Sep 2025 12:41:59 +0700 Message-ID: <20250916054202.582074-3-bagasdotme@gmail.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250916054202.582074-2-bagasdotme@gmail.com> References: <20250916054202.582074-2-bagasdotme@gmail.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5050; i=bagasdotme@gmail.com; h=from:subject; bh=iFycX2BAN7hX0KeER10Qq/N2vEd9PT/ZiaaR3gB9rS8=; b=owGbwMvMwCX2bWenZ2ig32LG02pJDBknfpglNjptrzyX3jn74zxGyanyl11lQifv9qu+If2Br +pY0t/cjlIWBjEuBlkxRZZJiXxNp3cZiVxoX+sIM4eVCWQIAxenAEzEyYCRYU76nXPz/mb+fH3F ++EcZvnZeaXh+YdVnUTyOjYsXJT8pJKR4YhJQHeT/mn5no+CkT8lPTPPnbbyWJvTt679SPPj8G0 lzAA= X-Developer-Key: i=bagasdotme@gmail.com; a=openpgp; fpr=701B806FDCA5D3A58FFB8F7D7C276C64A5E44A1D Content-Transfer-Encoding: 8bit Section numbering in subsections of "Histogram Trigger Command" sections is inconsistent in order. In particular, "'hist' trigger examples" is erroneously numbered as 6.2, which is a leftover from b8df4a3634e08a ("tracing: Move hist trigger Documentation to histogram.txt"). Fix the order. Reviewed-by: Tom Zanussi Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Bagas Sanjaya --- Documentation/trace/histogram.rst | 34 +++++++++++++++---------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst index af6d2e15568ebd..d158dadaa42447 100644 --- a/Documentation/trace/histogram.rst +++ b/Documentation/trace/histogram.rst @@ -186,8 +186,8 @@ Documentation written by Tom Zanussi The examples below provide a more concrete illustration of the concepts and typical usage patterns discussed above. -'special' event fields ------------------------- +2.1. 'special' event fields +--------------------------- There are a number of 'special event fields' available for use as keys or values in a hist trigger. These look like and behave as if @@ -204,16 +204,16 @@ Documentation written by Tom Zanussi common_cpu int the cpu on which the event occurred. ====================== ==== ======================================= -Extended error information --------------------------- +2.2. Extended error information +------------------------------- For some error conditions encountered when invoking a hist trigger command, extended error information is available via the tracing/error_log file. See Error Conditions in :file:`Documentation/trace/ftrace.rst` for details. -6.2 'hist' trigger examples ---------------------------- +2.3. 'hist' trigger examples +---------------------------- The first set of examples creates aggregations using the kmalloc event. The fields that can be used for the hist trigger are listed @@ -1608,8 +1608,8 @@ Extended error information Entries: 7 Dropped: 0 -2.2 Inter-event hist triggers ------------------------------ +2.4. Inter-event hist triggers +------------------------------ Inter-event hist triggers are hist triggers that combine values from one or more other events and create a histogram using that data. Data @@ -1685,8 +1685,8 @@ pseudo-file. These features are described in more detail in the following sections. -2.2.1 Histogram Variables -------------------------- +2.5. Histogram Variables +------------------------ Variables are simply named locations used for saving and retrieving values between matching events. A 'matching' event is defined as an @@ -1789,8 +1789,8 @@ or assigned to a variable and referenced in a subsequent expression:: Variables can even hold stacktraces, which are useful with synthetic events. -2.2.2 Synthetic Events ----------------------- +2.6. Synthetic Events +--------------------- Synthetic events are user-defined events generated from hist trigger variables or fields associated with one or more other events. Their @@ -1846,7 +1846,7 @@ the command that defined it with a '!':: At this point, there isn't yet an actual 'wakeup_latency' event instantiated in the event subsystem - for this to happen, a 'hist trigger action' needs to be instantiated and bound to actual fields -and variables defined on other events (see Section 2.2.3 below on +and variables defined on other events (see Section 2.7. below on how that is done using hist trigger 'onmatch' action). Once that is done, the 'wakeup_latency' synthetic event instance is created. @@ -2094,8 +2094,8 @@ histogram:: Entries: 7 Dropped: 0 -2.2.3 Hist trigger 'handlers' and 'actions' -------------------------------------------- +2.7. Hist trigger 'handlers' and 'actions' +------------------------------------------ A hist trigger 'action' is a function that's executed (in most cases conditionally) whenever a histogram entry is added or updated. @@ -2526,8 +2526,8 @@ The following commonly-used handler.action pairs are available: kworker/3:2-135 [003] d..3 49.823123: sched_switch: prev_comm=kworker/3:2 prev_pid=135 prev_prio=120 prev_state=T ==> next_comm=swapper/3 next_pid=0 next_prio=120 -0 [004] ..s7 49.823798: tcp_probe: src=10.0.0.10:54326 dest=23.215.104.193:80 mark=0x0 length=32 snd_nxt=0xe3ae2ff5 snd_una=0xe3ae2ecd snd_cwnd=10 ssthresh=2147483647 snd_wnd=28960 srtt=19604 rcv_wnd=29312 -3. User space creating a trigger --------------------------------- +2.8. User space creating a trigger +---------------------------------- Writing into /sys/kernel/tracing/trace_marker writes into the ftrace ring buffer. This can also act like an event, by writing into the trigger -- An old man doll... just what I always wanted! - Clara