From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9AD116A94A; Tue, 29 Jul 2025 01:26:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753752401; cv=none; b=tfT9+NwtD92nZz7toEn29lknQ58/qEOYNx1943RYHL3weOxij1V9AW2aIyklkHGBcyy2fQ1Lo8s7Ep1SaAIATwWJNO9qdum/xGs0skAPWBc4lmI0lRfcV6Qrvh2WkaHe/KSdIiIqzambekq42DcD+miMnxPqo5DxOIr0I/Tvqlo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753752401; c=relaxed/simple; bh=AlK0rmaizb0Qu3szybRB7RrQ8xRaclMecsdPl07+WSM=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=nkdbASTleWdLfwQE+GH892cUHqOAn6nRxoQvx6s0mPr2SFuLUolZGBtp6KO0rkEncn2qdeKzmdNTbXoUOqPozREKnZRiwKEtWSYTJnM1nNISWnx1qlfhgcPWar/F8VHTNQAEL+fl91zh2V5UNbtju6GOHmqCk0xSUhQuJUCklaU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aijiz0tH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aijiz0tH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBC28C4CEE7; Tue, 29 Jul 2025 01:26:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753752401; bh=AlK0rmaizb0Qu3szybRB7RrQ8xRaclMecsdPl07+WSM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=aijiz0tH51LfkyJZWt6f2kO9J+42hoEan2sbTOooXTkRP56EsMwVmT+pKvvYa9XIs gHg3EwjOHzVvUp9teh8Ap1T1RI22WCiSOarBXrUZeiB3PyD8lYS2prZVLjbcN8+hBc RPmRp5SK7cG5QP87X0tdVtP5X0O6A7rF+Mi7R1sW4PWVPnh3KfgfWWd2TZ5yCQUtd2 PhEex/reRr7GMEL1KbCYQWqmJlriiHWGmvJA9uu+HPXaUN0CFmzCIWhP60ft2sQdAd Q9xYWFAmNSJ9x+ouQ0siF0MDhO4ve4yzTN6cDLGkECae0gjJXBXtwYyGVf5jtLDJyN TJ9T3whDK/0tw== Date: Tue, 29 Jul 2025 10:26:36 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: LKML , Linux trace kernel , linux-doc@vger.kernel.org, Masami Hiramatsu , Mathieu Desnoyers , Mark Rutland , Andrew Morton , Namhyung Kim , Jonathan Corbet Subject: Re: [PATCH] Documentation: tracing: Add documentation about eprobes Message-Id: <20250729102636.b7cce553e7cc263722b12365@kernel.org> In-Reply-To: <20250728171522.7d54e116@batman.local.home> References: <20250728171522.7d54e116@batman.local.home> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 28 Jul 2025 17:15:22 -0400 Steven Rostedt wrote: > From: Steven Rostedt > > Eprobes was added back in 5.15, but was never documented. It became a > "secret" interface even though it has been a topic of several > presentations. For some reason, when eprobes was added, documenting it > never became a priority, until now. > Thanks for the document! > Signed-off-by: Steven Rostedt (Google) > --- > Documentation/trace/eprobes.rst | 268 ++++++++++++++++++++++++++++++++ > Documentation/trace/index.rst | 1 + > 2 files changed, 269 insertions(+) > create mode 100644 Documentation/trace/eprobes.rst > > diff --git a/Documentation/trace/eprobes.rst b/Documentation/trace/eprobes.rst > new file mode 100644 > index 000000000000..c7aa7c867e9e > --- /dev/null > +++ b/Documentation/trace/eprobes.rst BTW, can't you rename it as 'eprobetrace.rst' as same as others? I usually name the doc of "a probe feature which provides only in-kernel APIs" as '*probe.rst' and the doc of "a probe *event* feature which can controlled via tracefs interface" as '*probetrace.rst'. > @@ -0,0 +1,268 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +===================== > +Eprobe - Event probes What about below title? Eprobe - Event-based Probe Tracing > +===================== > + > +:Author: Steven Rostedt > + > +- Written for v6.17 > + > +Overview > +======== > + > +Eprobes are dynamic events that are placed on existing events to eiter > +dereference a field that is a pointer, or simply to limit what fields get > +recorded in the trace event. > + > +Eprobes depend on kprobe events so to enable this feature, build your kernel > +with CONFIG_KPROBE_EVENTS=y. Is this correct? It seems that eprobe event only depends on event trigger (by implementation. Actually we should fix the kernel/trace/Kconfig.) https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git/tree/kernel/trace/trace_eprobe.c?h=trace-v6.16-rc5#n576 Thank you, -- Masami Hiramatsu (Google)