From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759834Ab2ILPQp (ORCPT ); Wed, 12 Sep 2012 11:16:45 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:42734 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759456Ab2ILPQm (ORCPT ); Wed, 12 Sep 2012 11:16:42 -0400 From: David Ahern To: acme@ghostprotocols.net, linux-kernel@vger.kernel.org, peterz@infradead.org Cc: David Ahern , Ingo Molnar , Robert Richter Subject: [PATCH 3/3 v2] perf tool: give user better message if precise is not supported Date: Wed, 12 Sep 2012 09:16:30 -0600 Message-Id: <1347462990-29481-4-git-send-email-dsahern@gmail.com> X-Mailer: git-send-email 1.7.10.1 In-Reply-To: <1347462990-29481-1-git-send-email-dsahern@gmail.com> References: <1347462990-29481-1-git-send-email-dsahern@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Platforms (e.g., VM's) without support for precise mode get a confusing error message. e.g., $ perf record -e cycles:p -a -- sleep 1 Error: sys_perf_event_open() syscall returned with 95 (Operation not supported). /bin/dmesg may provide additional information. No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the "lapic" boot parameter to force-enable it. sleep: Terminated which is not clear that precise mode might be the root problem. With this patch: $ perf record -e cycles:p -fo /tmp/perf.data -- sleep 1 Error: 'precise' request may not be supported. Try removing 'p' modifier sleep: Terminated v2: softened message to 'may not be' supported per Robert's suggestion Signed-off-by: David Ahern Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Robert Richter --- tools/perf/builtin-record.c | 5 +++++ tools/perf/builtin-top.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index c643ed6..385e272 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -294,6 +294,11 @@ try_again: perf_evsel__name(pos)); rc = -err; goto out; + } else if ((err == EOPNOTSUPP) && (attr->precise_ip)) { + ui__error("\'precise\' request may not be supported. " + "Try removing 'p' modifier\n"); + rc = -err; + goto out; } printf("\n"); diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 5550754..1d1c98c 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -976,6 +976,10 @@ try_again: ui__error("Too many events are opened.\n" "Try again after reducing the number of events\n"); goto out_err; + } else if ((err == EOPNOTSUPP) && (attr->precise_ip)) { + ui__error("\'precise\' request may not be supported. " + "Try removing 'p' modifier\n"); + goto out_err; } ui__error("The sys_perf_event_open() syscall " -- 1.7.10.1