Commit 98310707 authored Jun 20, 2018 by Jiri Olsa Committed by Arnaldo Carvalho de Melo Jun 25, 2018

perf bench: Fix numa report output code



Currently we can hit following assert when running numa bench:

  $ perf bench numa mem -p 3 -t 1 -P 512 -s 100 -zZ0cm --thp 1
  perf: bench/numa.c:1577: __bench_numa: Assertion `!(!(((wait_stat) & 0x7f) == 0))' failed.

The assertion is correct, because we hit the SIGFPE in following line:

  Thread 2.2 "thread 0/0" received signal SIGFPE, Arithmetic exception.
  [Switching to Thread 0x7fffd28c6700 (LWP 11750)]
  0x000.. in worker_thread (__tdata=0x7.. ) at bench/numa.c:1257
  1257 td->speed_gbs = bytes_done / (td->runtime_ns / NSEC_PER_SEC) / 1e9;

We don't check if the runtime is actually bigger than 1 second,
and thus this might end up with zero division within FPU.

Adding the check to prevent this.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180620094036.17278-1-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 6dde6429

tools/perf/bench/numa.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1098,7 +1098,7 @@ static void worker_thread(void __tdata)
		u8 *global_data;
		u8 *process_data;
		u8 *thread_data;
		u64 bytes_done;
		u64 bytes_done, secs;
		long work_done;
		u32 l;
		struct rusage rusage;
		@@ -1254,7 +1254,8 @@ static void worker_thread(void __tdata)
		timersub(&stop, &start0, &diff);
		td->runtime_ns = diff.tv_sec * NSEC_PER_SEC;
		td->runtime_ns += diff.tv_usec * NSEC_PER_USEC;
		td->speed_gbs = bytes_done / (td->runtime_ns / NSEC_PER_SEC) / 1e9;
		secs = td->runtime_ns / NSEC_PER_SEC;
		td->speed_gbs = secs ? bytes_done / secs / 1e9 : 0;

		getrusage(RUSAGE_THREAD, &rusage);
		td->system_time_ns = rusage.ru_stime.tv_sec * NSEC_PER_SEC;

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