From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752272AbaLRG3y (ORCPT ); Thu, 18 Dec 2014 01:29:54 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58592 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250AbaLRG3x (ORCPT ); Thu, 18 Dec 2014 01:29:53 -0500 Date: Wed, 17 Dec 2014 22:29:15 -0800 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: dzickus@redhat.com, namhyung@kernel.org, paulus@samba.org, efault@gmx.de, fweisbec@gmail.com, adrian.hunter@intel.com, tglx@linutronix.de, mingo@kernel.org, acme@redhat.com, peterz@infradead.org, jolsa@redhat.com, linux-kernel@vger.kernel.org, eranian@google.com, bp@suse.de, hpa@zytor.com, dsahern@gmail.com Reply-To: jolsa@redhat.com, peterz@infradead.org, acme@redhat.com, mingo@kernel.org, dsahern@gmail.com, hpa@zytor.com, bp@suse.de, eranian@google.com, linux-kernel@vger.kernel.org, paulus@samba.org, namhyung@kernel.org, dzickus@redhat.com, tglx@linutronix.de, adrian.hunter@intel.com, fweisbec@gmail.com, efault@gmx.de To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf evlist: Do not use hard coded value for a mmap_pages default Git-Commit-ID: 8185e881f9fd9a2fa01f9d45616f8587f485f2a6 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 8185e881f9fd9a2fa01f9d45616f8587f485f2a6 Gitweb: http://git.kernel.org/tip/8185e881f9fd9a2fa01f9d45616f8587f485f2a6 Author: Arnaldo Carvalho de Melo AuthorDate: Fri, 12 Dec 2014 17:46:45 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 16 Dec 2014 13:38:26 -0300 perf evlist: Do not use hard coded value for a mmap_pages default So far what is in there by default is what we were using: 512KB + the control page, but the admin may change that, and if it does to a smaller value, all calls to tooling for non root users start failing, requiring that the user manually set --mmap_pages/-m. Use instead what is in /proc/sys/kernel/perf_event_mlock_kb. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-2f6mtm8xu3wo5lhkql6jdblh@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 7847f38..ac80868 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -893,10 +893,22 @@ out_unmap: static size_t perf_evlist__mmap_size(unsigned long pages) { - /* 512 kiB: default amount of unprivileged mlocked memory */ - if (pages == UINT_MAX) - pages = (512 * 1024) / page_size; - else if (!is_power_of_2(pages)) + if (pages == UINT_MAX) { + int max; + + if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) { + /* + * Pick a once upon a time good value, i.e. things look + * strange since we can't read a sysctl value, but lets not + * die yet... + */ + max = 512; + } else { + max -= (page_size / 1024); + } + + pages = (max * 1024) / page_size; + } else if (!is_power_of_2(pages)) return 0; return (pages + 1) * page_size;