From 0014de172d228e450377d1fd079d94e67128d27f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 2 Nov 2015 12:10:25 +0100 Subject: [PATCH] perf sched latency: Fix thread pid reuse issue The latency subcommand holds a tree of working atoms sorted by thread's pid/tid. If there's new thread with same pid and tid, the old working atom is found and assert bug condition is hit in search function: thread_atoms_search: Assertion `!(thread != atoms->thread)' failed Changing the sort function to use thread object pointers together with pid and tid check. This way new thread will never find old one with same pid/tid. Link: http://lkml.kernel.org/n/tip-o4doazhhv0zax5zshkg8hnys@git.kernel.org Reported-by: Mohit Agrawal Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: David Ahern Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1446462625-15807-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-sched.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 0ee6d900e100..e3d3e32c0a93 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -1203,12 +1203,13 @@ static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_ static int pid_cmp(struct work_atoms *l, struct work_atoms *r) { + if (l->thread == r->thread) + return 0; if (l->thread->tid < r->thread->tid) return -1; if (l->thread->tid > r->thread->tid) return 1; - - return 0; + return (int)(l->thread - r->thread); } static int avg_cmp(struct work_atoms *l, struct work_atoms *r)