From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) (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 B9B9A29B78F; Wed, 12 Nov 2025 15:37:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762961882; cv=none; b=MU7Hynd0ouOPD59sbU0JJfEqEcFEUlzar0ITAwoFZfZ7HD9vICLWuLzio5O3GAVkQvIFkDmmN452ka12Gl0+O7MLAaiJFKvW1vpgplObs4j+uj4S1MymoB3Ucdyyp1VoE6H9LfkY7EN427V57oXsIayia6JgqoZQEt5Et2IOIF4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762961882; c=relaxed/simple; bh=hlpKTafb8GK7Ub3ROyL9kf18Ly4pyM4eaJtlKKSfkCU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aYyYc+6KWttDHkRdYtYaAQugT6+tb9KYVuzUNTl71UYyJdTuu1SPdWiFZ6nW5uZyyw72IxqpTLoTSxymX1F4af0zHEmHPoEhh+kAMN5gZsMuwBpFHOhOFZeCQOvKI4WDzTthq69krflpUyUfQ2G+8AIKP61qdBnVqVUY426TjeA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 51A004CDC7; Wed, 12 Nov 2025 15:37:53 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf10.hostedemail.com (Postfix) with ESMTPA id 4E6732F; Wed, 12 Nov 2025 15:37:51 +0000 (UTC) Date: Wed, 12 Nov 2025 10:38:04 -0500 From: Steven Rostedt To: Donglin Peng Cc: Masami Hiramatsu , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, Donglin Peng , Sven Schnelle Subject: Re: [PATCH v3 RESEND] function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously Message-ID: <20251112103804.4a43591a@gandalf.local.home> In-Reply-To: References: <20251112034333.2901601-1-dolinux.peng@gmail.com> X-Mailer: Claws Mail 3.20.0git84 (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 X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: 4E6732F X-Stat-Signature: s5fwrt7ws4byfa63c5z9k3dujotzoyjr X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/7hBq4gRd/dHHQ3qVz2I9TBXY8zPd3jgY= X-HE-Tag: 1762961871-310067 X-HE-Meta: U2FsdGVkX1+3fbg35+Tgwrit8u4tPx8LdgQC0mr0Kb3FDZVNCYptfQXaqHcySTqEXiiakz8TLtwci9hQup0oheVP71e2zKwk1CX5lAeTi1eOSx4C+BIWD+hsXA5o+9ueTVdv1lTSBVZqBxuL5ffVUgihJIX7OVS6COfmExKkwAQ5B6UejZdpidqW5axlilDbwVev8KBm4Afyw5PPtxer3RE5bEi+yKDYv2sj+gSKix2u8gepYD4E2u0ZmV2i4hGDIOjXTryxghntvRFt/06Vp791iMb+hEL9OEhKNChQvTCxt8KpOfuwZIg6MOQfkFak29pHIzC7qnB9q8UfCTj/to4rIqexDjdR On Wed, 12 Nov 2025 17:00:10 +0800 Donglin Peng wrote: > I have a question regarding the behavior of the funcgraph-args option. > > Currently, when the funcgraph-args flag is set, the function arguments > are saved. > However, when the flag is cleared, the trace output still displays the function > arguments unconditionally. Yes. The flag affects the behavior of the recording and not the displaying of the arguments. There's no reason *not* to show them if they have already been recorded. Recording the arguments causes a noticeable overhead which is why it is optional. > > I expected that the flag would control both saving and displaying the arguments. > But it seems that the current design only controls the saving. This > behavior seems > inconsistent. Not at all. The option is only for the recording. Otherwise, one might expect than they could do the recording and then after the fact enable "func-args" and expect to see them. That would be more inconsistent. > > I think we should add a check for the flag in the display part, > specifically before > calling print_function_args, to ensure that the arguments are only > displayed when > the flag is set. > > What are your thoughts? Big nope! The retaddr is different, as the information is somewhat redundant to the call chain and may cause more noise then needed. -- Steve