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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C3CF4CA9EAF for ; Wed, 30 Oct 2019 07:09:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9723320874 for ; Wed, 30 Oct 2019 07:09:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572419367; bh=XMwWjvlfkKHHww7Ks8HvSGOaLb6jeQzakvfWivfDqbI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AD1hcbZdTJsJbwUOaF9hS3h9sfm337LNousNCWetbGbcjahn3G4Qn0DfZUY+3rJYE yzbXWNbfks2OPUe1FSubKqJs7Zr65Yu1QWapY7wTEdTkxJTVIvk5QPQ+tPd6W7zuOa KHOnAKIIiOtFuN93mXQq3eKqkV275Obl9uQOPNJ0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727263AbfJ3HJ0 (ORCPT ); Wed, 30 Oct 2019 03:09:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:43092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726108AbfJ3HJ0 (ORCPT ); Wed, 30 Oct 2019 03:09:26 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D110120874; Wed, 30 Oct 2019 07:09:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572419365; bh=XMwWjvlfkKHHww7Ks8HvSGOaLb6jeQzakvfWivfDqbI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vGbowppJBlrf5Mz3oIW/SFlp0lELV3rDYmiG0P/47b9clc18RTQFatBCQoXQAYIiS +oKjl/hUJOh6zmueTDLux8xgnfhXixwI2SUG0H+3+iRlsxHNJqd1wzky+cVwO9tZ1g 5nTsePIcK488DioKMu5pNKhzCLeTOvZGACLQb38I= From: Masami Hiramatsu To: Arnaldo Carvalho de Melo Cc: Jiri Olsa , Namhyung Kim , Masami Hiramatsu , linux-kernel@vger.kernel.org Subject: [BUGFIX PATCH 1/4] perf probe: Skip end-of-sequence and non statement lines Date: Wed, 30 Oct 2019 16:09:21 +0900 Message-Id: <157241936090.32002.12156347518596111660.stgit@devnote2> X-Mailer: git-send-email 2.20.1 In-Reply-To: <157241935028.32002.10228194508152968737.stgit@devnote2> References: <157241935028.32002.10228194508152968737.stgit@devnote2> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Skip end-of-sequence and non-statement lines while walking through lines list. The "end-of-sequence" line information means "the current address is that of the first byte after the end of a sequence of target machine instructions." (DWARF version 4 spec 6.2.2) This actually means out of scope and we can not probe on it. On the other hand, the statement lines (is_stmt) means "the current instruction is a recommended breakpoint location. A recommended breakpoint location is intended to “represent” a line, a statement and/or a semantically distinct subpart of a statement." (DWARF version 4 spec 6.2.2) So, non-statement line info also should be skipped. These can reduce unneeded probe points and also avoid an error. E.g. without this patch, # perf probe -a "clear_tasks_mm_cpumask:1" Added new events: probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask:1) probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask:1) probe:clear_tasks_mm_cpumask_2 (on clear_tasks_mm_cpumask:1) probe:clear_tasks_mm_cpumask_3 (on clear_tasks_mm_cpumask:1) probe:clear_tasks_mm_cpumask_4 (on clear_tasks_mm_cpumask:1) You can now use it in all perf tools, such as: perf record -e probe:clear_tasks_mm_cpumask_4 -aR sleep 1 # This puts 5 probes on one line, but acutally it's not inlined function. This is because there are many non statement instructions at the function prologue. With this patch, # perf probe -a "clear_tasks_mm_cpumask:1" Added new event: probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask:1) You can now use it in all perf tools, such as: perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1 # Now perf-probe skips unneeded addresses. Fixes: 4cc9cec636e7 ("perf probe: Introduce lines walker interface") Signed-off-by: Masami Hiramatsu --- tools/perf/util/dwarf-aux.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index ac82fd937e4b..f31001d13bfb 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -782,6 +782,7 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) int decl = 0, inl; Dwarf_Die die_mem, *cu_die; size_t nlines, i; + bool flag; /* Get the CU die */ if (dwarf_tag(rt_die) != DW_TAG_compile_unit) { @@ -812,6 +813,12 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) "Possible error in debuginfo.\n"); continue; } + /* Skip end-of-sequence */ + if (dwarf_lineendsequence(line, &flag) != 0 || flag) + continue; + /* Skip Non statement line-info */ + if (dwarf_linebeginstatement(line, &flag) != 0 || !flag) + continue; /* Filter lines based on address */ if (rt_die != cu_die) { /*