Re: [PATCH] perf bench: Fix numa report output code

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Wed, Jun 20, 2018 at 11:40:36AM +0200, Jiri Olsa escreveu:
> 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.
> 
> Link: http://lkml.kernel.org/n/tip-9y8n4x48mjbbcay73sq6nche@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>

thanks, applied to perf/urgent.

- Arnaldo