From 7ed5d6e28a0a1a54f554b0ab9c38a6061e7cac9e Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 28 Jan 2016 00:40:53 +0900 Subject: [PATCH] perf report: Fix percent display in callchains on --stdio When there's only a single callchain, perf doesn't print its percentage in front of the symbols. This is because it assumes that the percentage is same as parents. But if a percent limit is applied, it's possible that there are actually a couple of child nodes but only one of them is shown. In this case it should display the percent to prevent misunderstanding of its percentage is same as the parent's. For example, let's see the following callchain. $ perf report -s comm --percent-limit 0.01 --stdio ... 9.95% swapper | |--7.57%--intel_idle | cpuidle_enter_state | cpuidle_enter | call_cpuidle | cpu_startup_entry | | | |--4.89%--start_secondary | | | --2.68%--rest_init | start_kernel | x86_64_start_reservations | x86_64_start_kernel | |--0.15%--__schedule | | | |--0.13%--schedule | | schedule_preempt_disable | | cpu_startup_entry | | | | | |--0.09%--start_secondary | | | | | --0.04%--rest_init | | start_kernel | | x86_64_start_reservations | | x86_64_start_kernel | | | --0.01%--schedule_preempt_disabled | cpu_startup_entry ... Current code omits the percent if 'intel_idle' becomes the only node when percent limit is set to 0.5%, its percent is not 9.95% but users will assume it incorrectly. Before: $ perf report --percent-limit 0.5 --stdio ... 9.95% swapper | ---intel_idle cpuidle_enter_state cpuidle_enter call_cpuidle cpu_startup_entry | |--4.89%--start_secondary | --2.68%--rest_init start_kernel x86_64_start_reservations x86_64_start_kernel After: $ perf report --percent-limit 0.5 --stdio ... 9.95% swapper | --7.57%--intel_idle cpuidle_enter_state cpuidle_enter call_cpuidle cpu_startup_entry | |--4.89%--start_secondary | --2.68%--rest_init start_kernel x86_64_start_reservations x86_64_start_kernel Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Andi Kleen Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1453909257-26015-7-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/ui/stdio/hist.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c index 96188ea12771..76ff46becac8 100644 --- a/tools/perf/ui/stdio/hist.c +++ b/tools/perf/ui/stdio/hist.c @@ -165,6 +165,25 @@ static size_t __callchain__fprintf_graph(FILE *fp, struct rb_root *root, return ret; } +/* + * If have one single callchain root, don't bother printing + * its percentage (100 % in fractal mode and the same percentage + * than the hist in graph mode). This also avoid one level of column. + * + * However when percent-limit applied, it's possible that single callchain + * node have different (non-100% in fractal mode) percentage. + */ +static bool need_percent_display(struct rb_node *node, u64 parent_samples) +{ + struct callchain_node *cnode; + + if (rb_next(node)) + return true; + + cnode = rb_entry(node, struct callchain_node, rb_node); + return callchain_cumul_hits(cnode) != parent_samples; +} + static size_t callchain__fprintf_graph(FILE *fp, struct rb_root *root, u64 total_samples, u64 parent_samples, int left_margin) @@ -178,13 +197,8 @@ static size_t callchain__fprintf_graph(FILE *fp, struct rb_root *root, int ret = 0; char bf[1024]; - /* - * If have one single callchain root, don't bother printing - * its percentage (100 % in fractal mode and the same percentage - * than the hist in graph mode). This also avoid one level of column. - */ node = rb_first(root); - if (node && !rb_next(node)) { + if (node && !need_percent_display(node, parent_samples)) { cnode = rb_entry(node, struct callchain_node, rb_node); list_for_each_entry(chain, &cnode->val, list) { /*