From d29d92df410e2fb523f640478b18f70c1823e55e Mon Sep 17 00:00:00 2001 From: Michael Petlan Date: Fri, 27 Sep 2024 17:19:26 +0200 Subject: [PATCH] perf trace: Keep exited threads for summary Since 9ffa6c7512ca ("perf machine thread: Remove exited threads by default") perf cleans exited threads up, but as said, sometimes they are necessary to be kept. The mentioned commit does not cover all the cases, we also need the information to construct the summary table in perf-trace. Before: # perf trace -s true Summary of events: After: # perf trace -s -- true Summary of events: true (383382), 64 events, 91.4% syscall calls errors total min avg max stddev (msec) (msec) (msec) (msec) (%) --------------- -------- ------ -------- --------- --------- --------- ------ mmap 8 0 0.150 0.013 0.019 0.031 11.90% mprotect 3 0 0.045 0.014 0.015 0.017 6.47% openat 2 0 0.014 0.006 0.007 0.007 9.73% munmap 1 0 0.009 0.009 0.009 0.009 0.00% access 1 1 0.009 0.009 0.009 0.009 0.00% pread64 4 0 0.006 0.001 0.001 0.002 4.53% fstat 2 0 0.005 0.001 0.002 0.003 37.59% arch_prctl 2 1 0.003 0.001 0.002 0.002 25.91% read 1 0 0.003 0.003 0.003 0.003 0.00% close 2 0 0.003 0.001 0.001 0.001 3.86% brk 1 0 0.002 0.002 0.002 0.002 0.00% rseq 1 0 0.001 0.001 0.001 0.001 0.00% prlimit64 1 0 0.001 0.001 0.001 0.001 0.00% set_robust_list 1 0 0.001 0.001 0.001 0.001 0.00% set_tid_address 1 0 0.001 0.001 0.001 0.001 0.00% execve 1 0 0.000 0.000 0.000 0.000 0.00% [namhyung: simplified the condition] Fixes: 9ffa6c7512ca ("perf machine thread: Remove exited threads by default") Reported-by: Veronika Molnarova Signed-off-by: Michael Petlan Link: https://lore.kernel.org/r/20240927151926.399474-1-mpetlan@redhat.com Signed-off-by: Namhyung Kim --- tools/perf/builtin-trace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index f6e847529073..0b30297b4ecb 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -5449,6 +5449,10 @@ init_augmented_syscall_tp: if (trace.summary_only) trace.summary = trace.summary_only; + /* Keep exited threads, otherwise information might be lost for summary */ + if (trace.summary) + symbol_conf.keep_exited_threads = true; + if (output_name != NULL) { err = trace__open_output(&trace, output_name); if (err < 0) { -- 2.25.1