Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933800Ab1CaBfa (ORCPT ); Wed, 30 Mar 2011 21:35:30 -0400 Received: from mail-ww0-f42.google.com ([74.125.82.42]:58050 "EHLO mail-ww0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933456Ab1CaBf3 (ORCPT ); Wed, 30 Mar 2011 21:35:29 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=hmuKCZ2Z2cnmMmClUlEsQ3iaITueqZGglgc2GgXYQ+i1+0mUpPNas7YGoFq+Ii4Gv/ TZ30jrtY/HmgpHx7UYn/AWulgQXAAeREzUyjzZeEZioBUo8cLaqLqrnKqL1O4dVMA6AQ 6jhNKGwkAGR/YiNjMf/TdogsQgUw+PsXGJVng= From: Frederic Weisbecker To: Arnaldo Carvalho de Melo Cc: LKML , Frederic Weisbecker , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Paul Mackerras , Stephane Eranian Subject: [PATCH 2/2] perf: Mmap 512 kiB by default Date: Thu, 31 Mar 2011 03:35:24 +0200 Message-Id: <1301535324-9735-1-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.3.2 In-Reply-To: <1301496028.4859.183.camel@twins> References: <1301496028.4859.183.camel@twins> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1995 Lines: 54 The default setting of perf record is to mmap 128 pages if the user did not override with -m. However the page size may vary accross different architecture settings, giving different default size between each. Moreover the kernel side still has a default max number of mlocked pages of 512 kiB + 1 page for unprivileged users. 128 + 1 pages with page size > 4096 overlaps this threshold. Thus, better adapt to this limitation and set the default number of pages to fit those 512 kiB + 1 page. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Stephane Eranian --- tools/perf/builtin-record.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 6febcc1..a7e14bd 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -41,7 +41,7 @@ static u64 user_interval = ULLONG_MAX; static u64 default_interval = 0; static unsigned int page_size; -static unsigned int mmap_pages = 128; +static unsigned int mmap_pages = UINT_MAX; static unsigned int user_freq = UINT_MAX; static int freq = 1000; static int output; @@ -506,6 +506,10 @@ static int __cmd_record(int argc, const char **argv) if (have_tracepoints(&evsel_list->entries)) perf_header__set_feat(&session->header, HEADER_TRACE_INFO); + /* 512 kiB: default amount of unprivileged mlocked memory */ + if (mmap_pages == UINT_MAX) + mmap_pages = (512 * 1024) / page_size; + if (forks) { child_pid = fork(); if (child_pid < 0) { -- 1.7.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/