From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753584AbeDPGrq (ORCPT ); Mon, 16 Apr 2018 02:47:46 -0400 Received: from terminus.zytor.com ([198.137.202.136]:59453 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752221AbeDPGrn (ORCPT ); Mon, 16 Apr 2018 02:47:43 -0400 Date: Sun, 15 Apr 2018 23:47:35 -0700 From: tip-bot for Thomas Richter Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, brueckner@linux.vnet.ibm.com, heiko.carstens@de.ibm.com, tmricht@linux.ibm.com, tglx@linutronix.de, acme@redhat.com, mingo@kernel.org, schwidefsky@de.ibm.com Reply-To: schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, tmricht@linux.ibm.com, hpa@zytor.com, linux-kernel@vger.kernel.org, brueckner@linux.vnet.ibm.com, mingo@kernel.org, acme@redhat.com, tglx@linutronix.de In-Reply-To: <20180412133246.92801-1-tmricht@linux.ibm.com> References: <20180412133246.92801-1-tmricht@linux.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf record: Change warning for missing sysfs entry to debug Git-Commit-ID: 4f75f1cbf95e2f0853cd229d042b203931b899af 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: 4f75f1cbf95e2f0853cd229d042b203931b899af Gitweb: https://git.kernel.org/tip/4f75f1cbf95e2f0853cd229d042b203931b899af Author: Thomas Richter AuthorDate: Thu, 12 Apr 2018 15:32:46 +0200 Committer: Arnaldo Carvalho de Melo CommitDate: Fri, 13 Apr 2018 09:59:56 -0300 perf record: Change warning for missing sysfs entry to debug Using perf on 4.16.0 kernel on s390 shows this warning: failed: can't open node sysfs data each time I run command perf record ... for example: [root@s35lp76 perf]# ./perf record -e rB0000 -- sleep 1 [ perf record: Woken up 1 times to write data ] failed: can't open node sysfs data [ perf record: Captured and wrote 0.001 MB perf.data (4 samples) ] [root@s35lp76 perf]# It turns out commit e2091cedd51bf ("perf tools: Add MEM_TOPOLOGY feature to perf data file") tries to open directory named /sys/devices/system/node/ which does not exist on s390. This is the call stack: __cmd_record +---> perf_session__write_header +---> perf_header__adds_write +---> do_write_feat +---> write_mem_topology +---> build_mem_topology prints warning The issue starts in do_write_feat() which unconditionally loops over all features and now includes HEADER_MEM_TOPOLOGY and calls write_mem_topology(). Function record__init_features() at the beginning of __cmd_record() sets all features and then turns off some of them. Fix this by changing the warning to a level 2 debug output statement. So it is only shown when debug level 2 or higher is set. Signed-off-by: Thomas Richter Cc: Heiko Carstens Cc: Hendrik Brueckner Cc: Martin Schwidefsky Link: http://lkml.kernel.org/r/20180412133246.92801-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 121df1683c36..a8bff2178fbc 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1320,7 +1320,8 @@ static int build_mem_topology(struct memory_node *nodes, u64 size, u64 *cntp) dir = opendir(path); if (!dir) { - pr_warning("failed: can't open node sysfs data\n"); + pr_debug2("%s: could't read %s, does this arch have topology information?\n", + __func__, path); return -1; }