From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45656 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726694AbeHWLjR (ORCPT ); Thu, 23 Aug 2018 07:39:17 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiri Olsa , Alexander Shishkin , David Ahern , Namhyung Kim , Peter Zijlstra , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 4.9 049/130] perf bench: Fix numa report output code Date: Thu, 23 Aug 2018 09:52:45 +0200 Message-Id: <20180823074930.404575147@linuxfoundation.org> In-Reply-To: <20180823074927.161454870@linuxfoundation.org> References: <20180823074927.161454870@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa [ Upstream commit 983107072be1a39cbde67d45cb0059138190e015 ] 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 Cc: Alexander Shishkin Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180620094036.17278-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- tools/perf/bench/numa.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/tools/perf/bench/numa.c +++ b/tools/perf/bench/numa.c @@ -1093,7 +1093,7 @@ 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; @@ -1249,7 +1249,8 @@ 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;