From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752627AbZHILNQ (ORCPT ); Sun, 9 Aug 2009 07:13:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752078AbZHILNP (ORCPT ); Sun, 9 Aug 2009 07:13:15 -0400 Received: from hera.kernel.org ([140.211.167.34]:40982 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751899AbZHILNO (ORCPT ); Sun, 9 Aug 2009 07:13:14 -0400 Date: Sun, 9 Aug 2009 11:12:40 GMT From: tip-bot for Frederic Weisbecker To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20090809024235.GA10146@nowhere> References: <20090809024235.GA10146@nowhere> Subject: [tip:perfcounters/urgent] perf tools: callchain: Fix bad rounding of minimum rate Message-ID: Git-Commit-ID: c0a8865e32c8d1a562db38e06ef31ef23282f646 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sun, 09 Aug 2009 11:12:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c0a8865e32c8d1a562db38e06ef31ef23282f646 Gitweb: http://git.kernel.org/tip/c0a8865e32c8d1a562db38e06ef31ef23282f646 Author: Frederic Weisbecker AuthorDate: Sun, 9 Aug 2009 04:19:15 +0200 Committer: Ingo Molnar CommitDate: Sun, 9 Aug 2009 13:07:46 +0200 perf tools: callchain: Fix bad rounding of minimum rate Sometimes we get callchain branches that have a rate under the limit given by the user. Say you launched: perf record -f -g -a ./hackbench 10 perf report -g fractal,10.0 And you got: 2.33% hackbench [kernel] [k] _spin_lock_irqsave | |--78.57%-- remove_wait_queue | poll_freewait | do_sys_poll | sys_poll | sysenter_dispatch | 0xf7ffa430 | 0x1ffadea3c | |--7.14%-- __up_read | up_read | do_page_fault | page_fault | 0xf7ffa430 | 0xa0df710000000a ... It is abnormal to get a 7.14% branch whereas we passed a 10% filter. The problem is that we round down the minimum threshold. This happens mostly when we have very low number of events. If the total amount of your branch is 4 and you have a subranch of 3 events, filtering to 90% will be computed like follows: limit = 4 * 0.9; The result is about 3.6, but the cast to integer will round down to 3. It means that our filter is actually of 75% We must then explicitly round up the minimum threshold. Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: acme@redhat.com Cc: peterz@infradead.org Cc: efault@gmx.de LKML-Reference: <20090809024235.GA10146@nowhere> Signed-off-by: Ingo Molnar --- tools/perf/util/callchain.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index a8e67aa..0114734 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -13,6 +13,7 @@ #include #include #include +#include #include "callchain.h" @@ -112,7 +113,7 @@ static void __sort_chain_graph_rel(struct callchain_node *node, u64 min_hit; node->rb_root = RB_ROOT; - min_hit = node->children_hit * min_percent / 100.0; + min_hit = ceil(node->children_hit * min_percent); chain_for_each_child(child, node) { __sort_chain_graph_rel(child, min_percent); @@ -126,7 +127,7 @@ static void sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_node *chain_root, u64 min_hit __used, struct callchain_param *param) { - __sort_chain_graph_rel(chain_root, param->min_percent); + __sort_chain_graph_rel(chain_root, param->min_percent / 100.0); rb_root->rb_node = chain_root->rb_root.rb_node; }