From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 993D44A5EB4; Wed, 2 Sep 2026 14:55:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788360942; cv=none; b=bhyN9Fyb3pSfoXzsCU9IAVbEQ5qu6Vak4mvfV/23yPBI3v/x3XIRBbBLZsxvEsZOlwpVJzegIizJSb7EIp1mfw3lCPNAfEmYs0IND9DjQSEwzPwD7t2hG3odNxR41XQA5FyrcXSwgAJWPxtItFoWHHHdNytP9PrO4psZ0L4hJCk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788360942; c=relaxed/simple; bh=OgD0qGPB5f+MJB13UFV92iCXE2XY2AgqTqZKVf2ib7U=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=pgE4xVNDGjk0b2fzYcLO0i+ecKVZoqBs8sc5nXgICVT2YnM0ESp9sFOiu5IV83K/dZuIuheGDEHsCboNAZ0pdyITXnuleBb/c1JmUB5OXV/Iq5qkqgRnk/A8LaJRn1Wt5DQ81vTDExYJp8lnoclz0fzj+jeCc1u68AS9jXu+syg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=elfU7kO/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="elfU7kO/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 100221F000E9; Wed, 2 Sep 2026 14:55:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788360938; bh=4VkIc8pjkpY1oFoTfyYo3gvdAh5Yf+vjfAn89/ZsDGM=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=elfU7kO/7Y0JO3xq65MZpi2xurdnDenwPNo1FjzKUbil7EKy1r1A4a5IdW27RfdXF 6tz8XM85yXqGcn/0N5TR2eCZvNMi5A/k5YdEvfJQoqt7l6FDJZZyOVbGE+NQbWKwfB 4DVVoZ/N+IEril7xQY3nWFHTNTJjZHkfEWCEuCJQ2Rl+Diad5twnqhjtG5oHm46QG5 G26MfD/XoymgRsOBZOyF282TJYNSkR4aOUDXiexPp9+0Wg6TcWnujaZXCAm8bu9Y4b kRgaHn4UEOG7dEkT/MOJBtIEoBTKqZj+Z37x1BmnhrQG/5ZUS7zxDETlqiYiyh6Ad8 egdRe/a23z+Lw== Date: Wed, 2 Sep 2026 23:55:33 +0900 From: Masami Hiramatsu (Google) To: Peng Donglin Cc: Steven Rostedt , mhiramat@kernel.org, dolinux.peng@gmai.com, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, pengdonglin Subject: Re: [PATCH v5 0/3] Use BTF to trim return values Message-Id: <20260902235533.ea387f764b51b1b2a8ce8224@kernel.org> In-Reply-To: References: <20260901134604.4052265-1-dolinux.peng@gmail.com> <20260901135715.4812fde9@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 Wed, 2 Sep 2026 11:25:29 +0800 Peng Donglin wrote: > >> - Do not print a return value for functions with a void return type. > >> - Trim integer, enum, struct, and union values to the available return > >> value width when the BTF type provides suitable size information. > >> - Format integer, enum, and boolean values according to their BTF > >> encoding. > >> - Mark values as "(trunc)" when the return type is wider than the > >> value captured by the function graph tracer. > > > > Hmm, I really don't like the "(trunc)" If it's the real return type, then > > it should just print what the real size is. No need to state it was truncated. > > Thanks, I agree. We can remove the "(trunc)" suffix and print the actual > type information instead, for example: > > ret=0x5[struct:0x10] > > This would indicate that the return type is a struct with a size of 0x10 > bytes. Hmm, shouldn't both the actually applied size and the true size be displayed? e.g. ret=0x5 (in 8 bytes, true size: 16 bytes) Thank you, > > Would this be acceptable? > > > -- Masami Hiramatsu (Google)