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 50A1C187327 for ; Wed, 17 Jul 2024 20:58:31 +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=1721249911; cv=none; b=N7llkR8jo6pib9CjF4vHJr5r4R08f1AvBlempfnf2nyFXJfFdEPxSvyHSR3F/gYE6Bad6LsEum0oOQaZ8fZN1VRNC+IVzOe/FFNiI9nYpG8jNdMda0526J7J8pE3LpzkJBap+IGe6Y2Yv3h82nNPogKRCnU+uHrZP2+GMtmObGI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721249911; c=relaxed/simple; bh=dy4Jg3NUHHGmlR0vwh3nvixqW/CK6d802WIlRTe1jlk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ahrcXT3UOZDJdJuMh26YJmVKaKP05lawzToSILcAgE6iscVAznahd6fUM6D6k4zJlk6FgzR8PKTVzh4Si9uY552ulAORF9+LeYSIvxLtJMuEtPSrTOEoRvML3NQVFIojm292dem/QkZnFCxS+aLiuYrmzhB5rTyjbu+wJbhU48o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B579C2BD10; Wed, 17 Jul 2024 20:58:30 +0000 (UTC) Date: Wed, 17 Jul 2024 16:58:28 -0400 From: Steven Rostedt To: Jianfeng Wang Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH v2 2/2] trace-cmd: Add ftrace options for the fgraph retval feature Message-ID: <20240717165828.61057625@rorschach.local.home> In-Reply-To: <228cdfa6-29a5-4647-aefb-7fa04c1b1a00@oracle.com> References: <20240521213730.67993-1-jianfeng.w.wang@oracle.com> <20240521213730.67993-3-jianfeng.w.wang@oracle.com> <20240717145028.73683d09@rorschach.local.home> <228cdfa6-29a5-4647-aefb-7fa04c1b1a00@oracle.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-devel@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, 17 Jul 2024 13:44:43 -0700 Jianfeng Wang wrote: > On 7/17/24 11:50 AM, Steven Rostedt wrote: > > On Tue, 21 May 2024 14:37:30 -0700 > > Jianfeng Wang wrote: > > > >> Add two internal options for fgraph: fgraph:retval-skip and > >> fgraph:retval-hex. By default, trace-cmd will print each function's > >> return value at the function_graph exit point, if the kernel supports > >> the fgraph-retval feature. If users want to skip the output of > >> functions' return values, then set fgraph:retval-skip. Alternatively, > >> users can set fgraph:retval-hex to force the return values to be > >> printed in hex format. > >> > >> Here are example commands: > >>> trace-cmd report -O fgraph:retval-skip > >>> trace-cmd report -O fgraph:retval-hex > > > > I would like to see a -O fgraph:retval-dec > > > > As by default most is shown in hex, having an option to do that would > > be great. > > > > -- Steve > > > > > > Hi Steve, > > Sorry, I am confused about this. > > Do you suggesting adding one more option fgraph:retval-dec or > replacing fgraph:retval-hex with fgraph:retval-dec (and making the hex > format as the default)? I'd be happy to add both. > > Currently, the patch prints return values in decimal by default > (without any input), while users can specify fgraph:retval-hex to let > numbers printed in hex. It does? I don't see that: $ trace-cmd report [..] sleep-898 [006] ...1. 206.855186: funcgraph_entry: | mutex_unlock() { sleep-898 [006] ...1. 206.855188: funcgraph_entry: 1.439 us | __mutex_unlock_slowpath(); (ret=0x0) sleep-898 [006] ..... 206.855191: funcgraph_exit: 4.828 us | } (ret=0x0) sleep-898 [006] ...1. 206.855192: funcgraph_entry: 0.781 us | preempt_count_add(); (ret=0x202) sleep-898 [006] ...2. 206.855193: funcgraph_entry: | rcu_read_lock_any_held() { sleep-898 [006] ...2. 206.855194: funcgraph_entry: 0.738 us | rcu_lockdep_current_cpu_online(); (ret=0x1) sleep-898 [006] ...1. 206.855195: funcgraph_exit: 2.243 us | } (ret=0x1) sleep-898 [006] ...2. 206.855196: funcgraph_entry: 0.814 us | preempt_count_sub(); (ret=0x2f3e8) sleep-898 [006] ...1. 206.855198: funcgraph_entry: | __f_unlock_pos() { sleep-898 [006] ...1. 206.855199: funcgraph_entry: | mutex_unlock() { sleep-898 [006] ...1. 206.855199: funcgraph_entry: 0.851 us | __mutex_unlock_slowpath(); (ret=0x0) sleep-898 [006] ..... 206.855201: funcgraph_exit: 2.426 us | } (ret=0x0) sleep-898 [006] ..... 206.855202: funcgraph_exit: 3.994 us | } (ret=0x0) > >> @@ -235,8 +249,8 @@ print_graph_entry_leaf(struct trace_seq *s, > >> ret = trace_seq_printf(s, " (%lld)", depth); > >> > >> /* Return Value */ > >> - if (ret && fgraph_retval_supported) { > >> - if (!IS_LINUX_ERR_VALUE(retval)) > >> + if (ret && fgraph_retval_supported && !fgraph_retval_skip->set) { > >> + if (fgraph_retval_hex->set || !IS_LINUX_ERR_VALUE(retval)) It prints out hex if the value is not an error. Only errors show decimal output. -- Steve > >> ret = trace_seq_printf(s, " (ret=0x%llx)", retval); > >> else > >> ret = trace_seq_printf(s, " (ret=%lld)", retval); > >> @@ -385,8 +399,8 @@ fgraph_ret_handler(struct trace_seq *s, struct tep_record *record, > >> trace_seq_printf(s, " (%lld)", depth); > >> > >> /* Return Value */ > >> - if (fgraph_retval_supported) { > >> - if (!IS_LINUX_ERR_VALUE(retval)) > >> + if (fgraph_retval_supported && !fgraph_retval_skip->set) { > >> + if (fgraph_retval_hex->set || !IS_LINUX_ERR_VALUE(retval)) > >> trace_seq_printf(s, " (ret=0x%llx)", retval); > >> else > >> trace_seq_printf(s, " (ret=%lld)", retval); > >