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 X-Spam-Level: X-Spam-Status: No, score=-6.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2DB4C48BDF for ; Tue, 15 Jun 2021 05:42:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBC5E613F5 for ; Tue, 15 Jun 2021 05:42:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230238AbhFOFoa (ORCPT ); Tue, 15 Jun 2021 01:44:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:35202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229760AbhFOFo3 (ORCPT ); Tue, 15 Jun 2021 01:44:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 09B106140C; Tue, 15 Jun 2021 05:42:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623735745; bh=W6nJXbGyKFlPpe16ftnrzhJDjOUUwQ4jRCq5ZIlpKxY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Gu/dKIcCYGA3syEObcDkLEVGlLhjlSJ+vPtdgQ/fbD4+svJ92rpRujxvPW61tB0gg bVp+WQw90QmeeI1y4HrM7T6T2HjzIiMBwtHHNsJfbmgd0buvS/9sF2EGE+sYPLYE6n ItJrQ1jc/9RWQKblVV5+7oGerhqPTqgL4zcIRBONjoXQPB2MnhkA+VtPqGCk3TF4c9 zz2m/4wvUzgah9tlm5TvXh0B6zlHB5ITy1oKri+NBUsHPGQWveDMPnHzBmsoIewWe/ 0Bpl4atRcQAQK4TMdrpSo/5ggmwKyoFI9FSCoWznKZNESGQhR07lvxhcTi9jHkuMs7 pLcQfJBzOQAMw== Date: Tue, 15 Jun 2021 14:42:23 +0900 From: Masami Hiramatsu To: "Naveen N. Rao" Cc: "Aneesh Kumar K.V" , linux-kernel@vger.kernel.org, Peter Zijlstra , Steven Rostedt Subject: Re: [PATCH] kprobes: Print an error if probe is rejected Message-Id: <20210615144223.c4720bfdaff21ecb4d1e9101@kernel.org> In-Reply-To: <1623684669.fagfzw6pyl.naveen@linux.ibm.com> References: <20210610085617.1590138-1-naveen.n.rao@linux.vnet.ibm.com> <20210610191643.d24e7d56d102567070fe8386@kernel.org> <1623419180.o4u5xf72jm.naveen@linux.ibm.com> <20210612101347.a8e317344b0e6380d41f1cfe@kernel.org> <1623684669.fagfzw6pyl.naveen@linux.ibm.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; 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 Hi Naveen, On Mon, 14 Jun 2021 21:07:40 +0530 "Naveen N. Rao" wrote: > > > >> We also have perf_event_open() as an interface to add probes, and I > >> don't think it would be helpful to require all tools to utilize the > >> error log from tracefs for this purpose. > > > > No, perf probe doesn't use perf-event interface to add probes. It uses > > the tracefs for adding probes. > > Yes, but I was referring to some of the bpf tools (bcc) that now use > perf_event_open() interface. Yes, bpf chooses to use a special temporary perf_event, something like a performance counter event. Those are hidden from tracefs and perf-tool. The perf probe is the frontend of the trace event and perf event, which will add dynamic events in tracefs, and perf will use it as same as the other static events. Thank you, -- Masami Hiramatsu