Path: csiph.com!weretis.net!feeder4.news.weretis.net!news.unit0.net!news.panservice.it!diesel.cu.mi.it!bofh.it!news.nic.it!robomod From: Wang Nan Newsgroups: linux.kernel Subject: [PATCH v12 1/8] perf tests: Skip backward ring buffer on old kernel Date: Fri, 01 Jul 2016 04:30:01 +0200 Message-ID: References: X-Original-To: , X-Mailer: git-send-email 1.8.3.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-Cfilter-Loop: Reflected X-Mirapoint-Virus-Rapid-Raw: score=unknown(0), refid=str=0001.0A020206.5775D446.0101,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-ID: 27cfac15bc7cbe894bfc762684d0f8a4 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 43 Organization: linux.* mail to news gateway X-Original-Cc: , , , Arnaldo Carvalho de Melo , Wang Nan X-Original-Date: Fri, 1 Jul 2016 02:23:44 +0000 X-Original-Message-ID: <1467339831-171169-2-git-send-email-wangnan0@huawei.com> X-Original-References: <1467339831-171169-1-git-send-email-wangnan0@huawei.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1434967 From: Arnaldo Carvalho de Melo 'perf test backward' FAILED on old kernel: [root@jouet ~]# perf test -v backward 45: Test backward reading from ring buffer : --- start --- mmap size 1052672B Unexpected counter: sample_count=0, comm_count=0 ---- end ---- Test backward reading from ring buffer: FAILED! [root@jouet ~]# Reason: when kernel doesn't support 'attr.backward', perf_evsel__open() will trim this bit and try again, unless evsel->overwrite is true. Set evsel->overwrite in this test. Signed-off-by: Wang Nan Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/backward-ring-buffer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c index e70313f..0731b0b 100644 --- a/tools/perf/tests/backward-ring-buffer.c +++ b/tools/perf/tests/backward-ring-buffer.c @@ -118,8 +118,10 @@ int test__backward_ring_buffer(int subtest __maybe_unused) perf_evlist__config(evlist, &opts, NULL); /* Set backward bit, ring buffer should be writing from end */ - evlist__for_each_entry(evlist, evsel) + evlist__for_each_entry(evlist, evsel) { + evsel->overwrite = true; evsel->attr.write_backward = 1; + } err = perf_evlist__open(evlist); if (err < 0) { -- 1.8.3.4