From e72655d97d24fff559b4ab59de791c3741a74c8c Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Sat, 28 Nov 2015 02:32:38 +0900 Subject: [PATCH] perf hists: Do not skip elided fields when processing samples If user gives a filter, perf marks the corresponding column elided and omits the output. But it should process and aggregates samples using the field, otherwise samples will be aggregated as if the column was not there resulted in incorrect output. For example, I'd like to set a filter on native_write_msr_safe. The original overhead of the function is negligible. $ perf report | grep native_write_msr_safe 0.00% swapper [kernel.vmlinux] native_write_msr_safe 0.00% perf [kernel.vmlinux] native_write_msr_safe However adding -S option gives different output. $ perf report -S native_write_msr_safe --percentage absolute | \ > grep -e swapper -e perf 51.47% swapper [kernel.vmlinux] 4.14% perf [kernel.vmlinux] Since it aggregated samples using comm and dso only. In fact, the above values are same when it sorts with -s comm,dso. $ perf report -s comm,dso | grep -e swapper -e perf 51.47% swapper [kernel.vmlinux] 4.14% perf [kernel.vmlinux] This resulted in TUI failure with -ERANGE since it tries to increase sample hit count for annotation with wrong symbols due to incorrect aggregation. This patch fixes it not to skip elided fields when comparing samples in order to insert them to the hists. Commiter note: After the patch, with a different workloads: # perf report --show-total-period -S native_write_msr_safe --stdio # # symbol: native_write_msr_safe # # Samples: 455 of event 'cycles:pp' # Event count (approx.): 134787489 # # Overhead Period Command Shared Object # ........ ...... ............... ................ # 0.22% 293081 qemu-system-x86 [vmlinux] 0.19% 255914 swapper [vmlinux] 0.00% 2054 Timer [vmlinux] 0.00% 1021 firefox [vmlinux] 0.00% 2 perf [vmlinux] # perf report --show-total-period | grep native_write_msr_safe Failed to open /tmp/perf-14838.map, continuing without symbols 0.22% 293081 qemu-system-x86 [vmlinux] [k] native_write_msr_safe 0.19% 255914 swapper [vmlinux] [k] native_write_msr_safe 0.00% 2054 Timer [vmlinux] [k] native_write_msr_safe 0.00% 1021 firefox [vmlinux] [k] native_write_msr_safe 0.00% 2 perf [vmlinux] [k] native_write_msr_safe # Reported-by: Ingo Molnar Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1448645559-31167-2-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/hist.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 4fd37d6..6e8e0ee 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -924,9 +924,6 @@ hist_entry__cmp(struct hist_entry *left, struct hist_entry *right) int64_t cmp = 0; perf_hpp__for_each_sort_list(fmt) { - if (perf_hpp__should_skip(fmt)) - continue; - cmp = fmt->cmp(fmt, left, right); if (cmp) break; @@ -942,9 +939,6 @@ hist_entry__collapse(struct hist_entry *left, struct hist_entry *right) int64_t cmp = 0; perf_hpp__for_each_sort_list(fmt) { - if (perf_hpp__should_skip(fmt)) - continue; - cmp = fmt->collapse(fmt, left, right); if (cmp) break; -- 2.7.4