From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 270DAC433EF for ; Wed, 5 Jan 2022 23:10:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245306AbiAEXKg (ORCPT ); Wed, 5 Jan 2022 18:10:36 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:60752 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231896AbiAEXKe (ORCPT ); Wed, 5 Jan 2022 18:10:34 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F1864B81E1F for ; Wed, 5 Jan 2022 23:10:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00ED8C36AE9; Wed, 5 Jan 2022 23:10:30 +0000 (UTC) Date: Wed, 5 Jan 2022 18:10:29 -0500 From: Steven Rostedt To: Masami Hiramatsu Cc: Xiangyang Zhang , mingo@redhat.com, oleg@redhat.com, namhyung.kim@lge.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tracing/kprobes: 'nmissed' not showed correctly for kretprobe Message-ID: <20220105181029.4fa08f6a@gandalf.local.home> In-Reply-To: <20220106073203.123c4f7e38cc07eccd02aa9b@kernel.org> References: <20211211150032.7568-1-xyz.sun.ok@gmail.com> <20220105141556.12fb2ceb@gandalf.local.home> <20220105142208.1dbc20cc@gandalf.local.home> <20220106073203.123c4f7e38cc07eccd02aa9b@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 6 Jan 2022 07:32:03 +0900 Masami Hiramatsu wrote: > OK, this is a good catch :), but there are 2 issues. > > 1. kretprobe can be skipped by 2 reasons, shortage of kretprobe_instance which > is counted by rp.nmissed, and kprobe itself is missed by some reason (this > can be happen if KPROBE_EVENTS_ON_NOTRACE=n. Thus, better solution is to show > 'tk->rp.nmissed + tk->rp.kp.nmissed'. > > 2. the commit c31ffb3ff633 is not actual commit which introduce this issue. > this was introduced by 4a846b443b4e ("tracing/kprobes: Cleanup kprobe tracer code.") > > 'git blame' tells you the commit which changes that line, but that can be just > a refactoring (renaming). I recommend you to search the correct one by 'git log -p'. Masami, thanks for the review. Xiangyang, can you please send a v2 with Masami's suggestions? -- Steve