From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756634Ab3KHJEd (ORCPT ); Fri, 8 Nov 2013 04:04:33 -0500 Received: from mga14.intel.com ([143.182.124.37]:49340 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751530Ab3KHJEa (ORCPT ); Fri, 8 Nov 2013 04:04:30 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="318646403" Message-ID: <527CAAAB.3000900@intel.com> Date: Fri, 08 Nov 2013 11:11:07 +0200 From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: David Ahern CC: acme@ghostprotocols.net, linux-kernel@vger.kernel.org, Ingo Molnar , Jiri Olsa Subject: Re: [PATCH] perf tool: Round mmap pages to power 2 References: <1383885392-31082-1-git-send-email-dsahern@gmail.com> In-Reply-To: <1383885392-31082-1-git-send-email-dsahern@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/11/13 06:36, David Ahern wrote: > Currently perf requires the -m / --mmap_pages option to be a power of 2. > To be more user friendly perf should automatically round this up to the > next power of 2. > > Currently: > $ perf record -m 3 -a -- sleep 1 > --mmap_pages/-m value must be a power of two.sleep: Terminated > > With patch: > $ perf record -m 3 -a -- sleep 1 > rounding mmap pages size to 16384 (4 pages) > ... This prevents: --out-pages=0 from working e.g. tools/perf/perf record -vv --out-pages=0 uname rounding mmap pages size to 4096 (1 pages) Although without this patch: tools/perf/perf record -vv --out-pages=0 uname --mmap_pages/-m value must be a power of two. usage: perf record [] [] or: perf record [] -- [] --out-pages Number of pages or size with units to use for output (default 64M) Also there is: tools/perf/perf record -vv --no-out-pages uname Segmentation fault (core dumped) > Signed-off-by: David Ahern > Suggested-by: Ingo Molnar > Cc: Ingo Molnar > Cc: Jiri Olsa > --- > tools/perf/util/evlist.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index b939221efd8d..9ec3a5a45f22 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -722,11 +722,6 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str, > if (val != (unsigned long) -1) { > /* we got file size value */ > pages = PERF_ALIGN(val, page_size) / page_size; > - if (pages < (1UL << 31) && !is_power_of_2(pages)) { > - pages = next_pow2(pages); > - pr_info("rounding mmap pages size to %lu (%lu pages)\n", > - pages * page_size, pages); > - } > } else { > /* we got pages count value */ > char *eptr; > @@ -737,6 +732,12 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str, > } > } > > + if (pages < (1UL << 31) && !is_power_of_2(pages)) { > + pages = next_pow2(pages); > + pr_info("rounding mmap pages size to %lu (%lu pages)\n", > + pages * page_size, pages); > + } > + > if (pages > UINT_MAX || pages > SIZE_MAX / page_size) { > pr_err("--mmap_pages/-m value too big\n"); > return -1;