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=-12.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS 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 502F2C43218 for ; Fri, 26 Apr 2019 07:38:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23361206E0 for ; Fri, 26 Apr 2019 07:38:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556264289; bh=mRXuhjLbOGTpJ0v5E3I1EoiWfYKwFwJP8uYncEc65iA=; h=From:To:Cc:Subject:Date:List-ID:From; b=bfZG60AErAx/yyvtX8G+jBwzPJu92Ford6AKdom6GJeDRqLjalkyLaRf1Au+fZwXE w2LSV3BqQ5uXOI0Yr5Yxd2YazGQVKiJikGep+2Udjrypq6p9kzNL5ay2GpaOyEkS88 +6gfYzTBgCdqx3Se1qZbH0P3GHpqtBiJWzeIK0jk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726184AbfDZHiH (ORCPT ); Fri, 26 Apr 2019 03:38:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725921AbfDZHiH (ORCPT ); Fri, 26 Apr 2019 03:38:07 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 011BB3082132; Fri, 26 Apr 2019 07:38:07 +0000 (UTC) Received: from krava.brq.redhat.com (unknown [10.43.17.48]) by smtp.corp.redhat.com (Postfix) with ESMTP id 707ED5D71A; Fri, 26 Apr 2019 07:38:05 +0000 (UTC) From: Jiri Olsa To: Arnaldo Carvalho de Melo Cc: lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Peter Zijlstra Subject: [PATCH] perf tools: Speed up report for perf compiled with linwunwind Date: Fri, 26 Apr 2019 09:38:04 +0200 Message-Id: <20190426073804.17238-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Fri, 26 Apr 2019 07:38:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When compiled with libunwind, perf does some preparatory work when processing side-band events. This is not needed when report actually don't unwind dwarf callchains, so it's disabled with dwarf_callchain_users bool. However we could move that check to higher level and shield more unwanted code for normal report processing, giving us following speed up on kernel build profile: Before: $ perf record make -j40 ... $ ll ../../perf.data -rw-------. 1 jolsa jolsa 461783932 Apr 26 09:11 perf.data $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 78,669,920,155 cycles:u 99,076,431,951 instructions:u # 1.26 insn per cycle 55.382823668 seconds time elapsed 27.512341000 seconds user 27.712871000 seconds sys After: $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 59,626,798,904 cycles:u 88,583,575,849 instructions:u # 1.49 insn per cycle 21.296935559 seconds time elapsed 20.010191000 seconds user 1.202935000 seconds sys The speed is higher with profile having many side-band events, because these trigger libunwind preparatory code. This does not apply for perf compiled with libdw for dwarf unwind, only for build with libunwind. Link: http://lkml.kernel.org/n/tip-rqm3489ghqq07fdrcpniynfs@git.kernel.org Signed-off-by: Jiri Olsa --- tools/perf/util/thread.c | 3 ++- tools/perf/util/unwind-libunwind-local.c | 6 ------ tools/perf/util/unwind-libunwind.c | 10 ++++++++++ 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 50678d318185..403045a2bbea 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -15,6 +15,7 @@ #include "map.h" #include "symbol.h" #include "unwind.h" +#include "callchain.h" #include @@ -327,7 +328,7 @@ static int thread__prepare_access(struct thread *thread) { int err = 0; - if (symbol_conf.use_callchain) + if (dwarf_callchain_users) err = __thread__prepare_access(thread); return err; diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c index f3c666a84e4d..25e1406b1f8b 100644 --- a/tools/perf/util/unwind-libunwind-local.c +++ b/tools/perf/util/unwind-libunwind-local.c @@ -617,8 +617,6 @@ static unw_accessors_t accessors = { static int _unwind__prepare_access(struct thread *thread) { - if (!dwarf_callchain_users) - return 0; thread->addr_space = unw_create_addr_space(&accessors, 0); if (!thread->addr_space) { pr_err("unwind: Can't create unwind address space.\n"); @@ -631,15 +629,11 @@ static int _unwind__prepare_access(struct thread *thread) static void _unwind__flush_access(struct thread *thread) { - if (!dwarf_callchain_users) - return; unw_flush_cache(thread->addr_space, 0, 0); } static void _unwind__finish_access(struct thread *thread) { - if (!dwarf_callchain_users) - return; unw_destroy_addr_space(thread->addr_space); } diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c index 9778b3133b77..c0811977d7d5 100644 --- a/tools/perf/util/unwind-libunwind.c +++ b/tools/perf/util/unwind-libunwind.c @@ -5,6 +5,7 @@ #include "session.h" #include "debug.h" #include "env.h" +#include "callchain.h" struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops; struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops; @@ -24,6 +25,9 @@ int unwind__prepare_access(struct thread *thread, struct map *map, struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops; int err; + if (!dwarf_callchain_users) + return 0; + if (thread->addr_space) { pr_debug("unwind: thread map already set, dso=%s\n", map->dso->name); @@ -65,12 +69,18 @@ int unwind__prepare_access(struct thread *thread, struct map *map, void unwind__flush_access(struct thread *thread) { + if (!dwarf_callchain_users) + return; + if (thread->unwind_libunwind_ops) thread->unwind_libunwind_ops->flush_access(thread); } void unwind__finish_access(struct thread *thread) { + if (!dwarf_callchain_users) + return; + if (thread->unwind_libunwind_ops) thread->unwind_libunwind_ops->finish_access(thread); } -- 2.20.1