From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757983Ab1LWVyr (ORCPT ); Fri, 23 Dec 2011 16:54:47 -0500 Received: from merlin.infradead.org ([205.233.59.134]:57958 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757849Ab1LWVxb (ORCPT ); Fri, 23 Dec 2011 16:53:31 -0500 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Nelson Elhage , Paul Mackerras , Peter Zijlstra , Arnaldo Carvalho de Melo Subject: [PATCH 06/15] perf: builtin-record: Provide advice if mmap'ing fails with EPERM. Date: Fri, 23 Dec 2011 19:53:09 -0200 Message-Id: <1324677198-5191-7-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.7.8.rc0.35.gee6df In-Reply-To: <1324677198-5191-1-git-send-email-acme@infradead.org> References: <1324677198-5191-1-git-send-email-acme@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nelson Elhage This failure is most likely due to running up against the kernel.perf_event_mlock_kb sysctl, so we can tell the user what to do to fix the issue. Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1324301972-22740-3-git-send-email-nelhage@nelhage.com Signed-off-by: Nelson Elhage Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index f8fd14f..56bb447 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -272,8 +272,15 @@ try_again: exit(-1); } - if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) + if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) { + if (errno == EPERM) + die("Permission error mapping pages.\n" + "Consider increasing " + "/proc/sys/kernel/perf_event_mlock_kb,\n" + "or try again with a smaller value of -m/--mmap_pages.\n" + "(current value: %d)\n", opts->mmap_pages); die("failed to mmap with %d (%s)\n", errno, strerror(errno)); + } if (rec->file_new) session->evlist = evlist; -- 1.7.8.rc0.35.gee6df