From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751398AbaJPOzL (ORCPT ); Thu, 16 Oct 2014 10:55:11 -0400 Received: from mail.kernel.org ([198.145.19.201]:43844 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750947AbaJPOzJ (ORCPT ); Thu, 16 Oct 2014 10:55:09 -0400 Date: Thu, 16 Oct 2014 11:55:04 -0300 From: Arnaldo Carvalho de Melo To: Wang Nan Cc: Peter Zijlstra , Paul Mackerras , Ingo Molnar , linux-kernel@vger.kernel.org, zhangzhiqiang.zhang@huawei.com, peifeiyue@huawei.com Subject: Re: [PATCH] perf tools: fix incorrect header string Message-ID: <20141016145504.GW3198@kernel.org> References: <1413343733-7973-1-git-send-email-wangnan0@huawei.com> <20141015151358.GK3198@kernel.org> <543F39A9.3030308@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <543F39A9.3030308@huawei.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Oct 16, 2014 at 11:21:13AM +0800, Wang Nan escreveu: > On 2014/10/15 23:13, Arnaldo Carvalho de Melo wrote: > > Em Wed, Oct 15, 2014 at 11:28:53AM +0800, Wang Nan escreveu: > >> Commit fbe96f29 (perf tools: Make perf.data more self-descriptive) > >> read '/proc/cpuinfo' to form cpu descriptor. For ARM, it finds > >> 'Processor' field. It is correct when the patch merged, but due to > >> commit b4b8f770 (ARM: kernel: update cpuinfo to print all online CPUs > >> features), the corresponding information becomes 'model name' field. > >> > >> This patch simply corrects it. > > > > It doesn't :-) > > > > It makes it work with kernels >= b4b8f770, and fail with older kernels. > > > > We need to somehow figure out where the right information is regardless > > of the kernel. > > > > - Arnaldo > > > > However it is a real problem. Look at output on arm platform at the > bottom of this mail, especially "cpudesc", "total memory" and "cmdline" field. Yeah, I haven't said it wasn't a problem, just that the proposed fix wasn't enough. - Arnaldo > By further debugging I found that the real problem resides in return value checking > when write header error. Please see my other patches: > > https://lkml.org/lkml/2014/10/15/612 > https://lkml.org/lkml/2014/10/15/611 > > I think at least one of them is required. > > Thanks. > > >> Signed-off-by: Wang Nan > >> --- > >> tools/perf/perf-sys.h | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/tools/perf/perf-sys.h b/tools/perf/perf-sys.h > >> index 937e432..4293970 100644 > >> --- a/tools/perf/perf-sys.h > >> +++ b/tools/perf/perf-sys.h > >> @@ -113,7 +113,7 @@ > >> #define mb() ((void(*)(void))0xffff0fa0)() > >> #define wmb() ((void(*)(void))0xffff0fa0)() > >> #define rmb() ((void(*)(void))0xffff0fa0)() > >> -#define CPUINFO_PROC "Processor" > >> +#define CPUINFO_PROC "model name" > >> #endif > >> > >> #ifdef __aarch64__ > >> -- > >> 1.8.4 > > > > bash-4.2# perf record ls > ... > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.001 MB perf.data (~36 samples) ] > bash-4.2# perf report --stdio --header > Error: > The perf.data file has no samples! > # ======== > # captured on: Fri Sep 12 10:09:10 2014 > # hostname : arma15el > # os release : 3.17.0+ > # perf version : 3.10.53 > # arch : armv7l > # nrcpus online : 4 > # nrcpus avail : 1 > # cpudesc : (null) > # total memory : 0 kB > # cmdline : > # event : name = cycles, type = 0, config = 0x0, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_kern = 0, excl_host = 0, excl_guest = 1, precise_ip = 0 > # pmu mappings: not available > # ======== > # > >