linux-kernel - Re: [PATCH 2/8] perf metrics: fix parse errors in cascade lake metrics

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Message-ID: <46e803f3-80a4-0d37-9d39-b625b947ac7f@linux.intel.com>
Date:   Thu, 23 Apr 2020 09:08:53 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Ian Rogers <irogers@...gle.com>, Andi Kleen <ak@...ux.intel.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Haiyan Song <haiyanx.song@...el.com>,
        Ravi Bangoria <ravi.bangoria@...ux.ibm.com>,
        John Garry <john.garry@...wei.com>,
        Leo Yan <leo.yan@...aro.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-perf-users <linux-perf-users@...r.kernel.org>,
        Stephane Eranian <eranian@...gle.com>
Subject: Re: [PATCH 2/8] perf metrics: fix parse errors in cascade lake
 metrics



On 4/23/2020 12:18 AM, Ian Rogers wrote:
> On Wed, Apr 22, 2020 at 8:34 AM Ian Rogers <irogers@...gle.com> wrote:
>>
>> On Wed, Apr 22, 2020 at 7:38 AM Andi Kleen <ak@...ux.intel.com> wrote:
>>>
>>> On Wed, Apr 22, 2020 at 12:48:03AM -0700, Ian Rogers wrote:
>>>> Remove over escaping with \\.
>>>> Remove extraneous if 1 if 0 == 1 else 0 else 0.
>>>
>>> So where do these parse errors happen exactly? Some earlier
>>> patches introduced them as regressions?
>>
>> I'll work to track down a Fixes tag. I can repro the Skylakex errors
>> without the test in this series, by doing:
>>
>> $ perf stat -M DRAM_Read_Latency sleep 1
>> Error:
>> The sys_perf_event_open() syscall returned with 22 (Invalid argument)
>> for event (cha/event=0x36\,uma
>> sk=0x21/).
>> /bin/dmesg | grep -i perf may provide additional information.
>>

I also think some patches introduced this regression. When we rollback 
to commit 61ec07f5917e (perf vendor events intel: Update all the Intel 
JSON metrics from TMAM 3.6.), there is no this error on CLX.

Thanks
Jin Yao

>> This was just the escaping issue. I'm less clear on the other cascade
>> lake issue, and it is a bit more work for me to test on cascade lake.
>> What is "if 1 if 0 == 1 else 0 else 0" trying to do? Perhaps hunting
>> for the Fixes will let me know, but it looks like a copy-paste error.
>>
>>> The original metrics worked without parse errors as far as I know.
>>
>> The skylake issue above repros on 5.2.17 and so it seems like it is
>> broken for a while. The test in this series will prevent this in the
>> future, but without this patch that test fails.
> 
> The parse errors were introduced with the metrics, so they've never worked:
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=fd5500989c8f3c3944ac0a144be04bae2506f7ba
> 
> I will send out a v2 with Fixes in the commit message but wanted to
> wait in case there was any more feedback. In particular the fixes to
> the new test and expr parser lex code. The lex code wasn't broken at
> the time the metrics were added and should be working again after this
> patch set.
> 
> Thanks,
> Ian
> 
>>> If it fixes something earlier it would need Fixes: tags.
>>
>> Working on it. Thanks for the input!
>>
>> Ian
>>
>>> -Andi