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 5914B7FD; Wed, 29 Jan 2025 00:14:10 +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=1738109651; cv=none; b=MN3veys9omkcvRCWA67veQHnMh3Ba7s1XGAOrqUJ01xq+8vs+UWNJsAMZHkwznuyFutfWAQudfva8yM9edNkfKyXr50gbACOjLWVw5j0DbVt/42B6NzxsEII0H7+Efrvzk5aKGhprEFQ74SfO+nTpGdNJwV9+DNmZnMDA2akkhY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738109651; c=relaxed/simple; bh=OMFJc0JoBQ8IgFwPGAsl7WSzObXZ/0rzZ211wDUhOYQ=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=hL7LYY5j/Y8AeRWkM5BUNQ4f//v5nnyN7zUpXMAtLFIqk+jk7/a7kdldtB4cyrRPoexL+9PtLFa7fIc0NK79aBAl+Q0UNjfifQ1k3Z2B2+eNMnqcIoydv9CQTkzqqhaQdfmpQnvsjtA9CSsbZPuw3ZqfLEeLtIFkKGxi5a1DDq8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ReIz/VrD; 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="ReIz/VrD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C442C4CED3; Wed, 29 Jan 2025 00:14:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738109650; bh=OMFJc0JoBQ8IgFwPGAsl7WSzObXZ/0rzZ211wDUhOYQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ReIz/VrDzk8E5pTA01lmaQFR9x+gIZBmib5bTe61wEhdLcB55KI9gJJ5l/ui0iqya gv++mPuACKRBkqBy2hpxH9jXdOymlX3RnyrPvWsG3tP3hO5DtnyXdYzxDj+akJ1siS 2DIdaCrfCBb9sZ1jx7iGDWR9anyEiGYeVQ9hDtDyQClHM0nDG/giT0xFLZwm24WZGO ygM2Ds1sAJXGoEjFQwz9B3oayzJwhmyGImED6aMty02XkWXW91h65eCbVTe1CKiVis 3lcSEzNmPxESHw6DHzy/VvPQqHoIwh/lq15f05/Os9lqkoxWftvMesH25Gmita3Pfk 1Hi/1iwujPQNw== Date: Wed, 29 Jan 2025 09:14:06 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: Mathieu Desnoyers , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-modules@vger.kernel.org Subject: Re: [RFC PATCH 2/3] tracing: Introduce "rel_stack" option Message-Id: <20250129091406.a086021e0633c488e5c22ae3@kernel.org> In-Reply-To: <20250128110700.741e68cd@gandalf.local.home> References: <173807861687.1525539.15082309716909038251.stgit@mhiramat.roam.corp.google.com> <173807863557.1525539.14465198884840039000.stgit@mhiramat.roam.corp.google.com> <20250128110700.741e68cd@gandalf.local.home> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@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 Tue, 28 Jan 2025 11:07:00 -0500 Steven Rostedt wrote: > On Wed, 29 Jan 2025 00:37:15 +0900 > "Masami Hiramatsu (Google)" wrote: > > > From: Masami Hiramatsu (Google) > > > > Since the relative offset stacktrace requires a special module loading > > events to decode binary, it should be an optional for normal use case. > > User can enable this feature via `options/relative-stacktrace`. > > > > Let's make this an entirely new event and not based on an option. Reason > being, there's no way for libtraceevent to know which this is. We could > even have a mixture of these in the trace. > > Instead of an option, we can add a new trigger: stacktrace_rel that will do > a relative stack trace. And the event can be kernel_stack_rel > > Then it can be enabled via: > > echo 'stacktrace_rel if prev_state & 3' > events/sched/sched_switch/trigger Oh, I thought this was another feature, adding a new trigger action. Can't we do this with the event defined by FTRACE_ENTRY_DUP()? Thank you, > > -- Steve -- Masami Hiramatsu (Google)