linux-kernel - Re: [PATCH v2 0/6] perf arm64 metricgroup support

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Message-ID: <1d800da3-ec94-3a37-eca9-1d3cf8543ba6@huawei.com>
Date:   Tue, 6 Apr 2021 12:02:36 +0100
From:   John Garry <john.garry@...wei.com>
To:     kajoljain <kjain@...ux.ibm.com>, "Paul A. Clarke" <pc@...ibm.com>
CC:     <will@...nel.org>, <mathieu.poirier@...aro.org>,
        <leo.yan@...aro.org>, <peterz@...radead.org>, <mingo@...hat.com>,
        <acme@...nel.org>, <mark.rutland@....com>,
        <alexander.shishkin@...ux.intel.com>, <jolsa@...hat.com>,
        <namhyung@...nel.org>, <irogers@...gle.com>, <linuxarm@...wei.com>,
        <kan.liang@...ux.intel.com>, <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <zhangshaokun@...ilicon.com>
Subject: Re: [PATCH v2 0/6] perf arm64 metricgroup support

On 30/03/2021 07:41, kajoljain wrote:
> 
> 
> On 3/30/21 2:37 AM, Paul A. Clarke wrote:
>> On Fri, Mar 26, 2021 at 10:57:40AM +0000, John Garry wrote:
>>> On 25/03/2021 20:39, Paul A. Clarke wrote:
>>>> On Thu, Mar 25, 2021 at 06:33:12PM +0800, John Garry wrote:
>>>>> Metric reuse support is added for pmu-events parse metric testcase.
>>>>> This had been broken on power9 recentlty:
>>>>> https://lore.kernel.org/lkml/20210324015418.GC8931@li-24c3614c-2adc-11b2-a85c-85f334518bdb.ibm.com/
>>>>
>>>> Much better.  Before:
>>>> --
>>>> $ perf test -v 10 2>&1 | grep -i error | wc -l
>>>> 112
>>>> --
>>>> After:
>>>> --
>>>> $ perf test -v 10 2>&1 | grep -i error | wc -l
>>>> 17
>>>> --
>>>>
>>>> And these seem like different types of issues:
>>>> --
>>>> $ perf test -v 10 2>&1 | grep -i error
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_powerbus0_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs01_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> Error string 'Cannot find PMU `nest_mcs23_imc'. Missing kernel support?' help '(null)'
>>>> --
>>>>
>>>
>>> This looks suspicious.
>>>
>>> Firstly, does /sys/bus/event_source/devices/nest_mcs01_imc (or others,
>>> above) exist on your system? I guess not.
>>>
>>> Secondly, checking Documentation/powerpc/imc.rst, we have examples of:
>>> nest_mcs01/PM_MCS01_64B_R...
>>>
>>> So is the PMU name correct in the metric file for nest_mcs01_imc? Looking at
>>> the kernel driver file, arch/powerpc/perf/imc-pmu.c, it seems to be correct.
>>> Not sure.
>>
>> I ran with a newer kernel, and the above errors disappeared, replaced with
>> about 10 of:
>> --
>> Error string 'Cannot find PMU `hv_24x7'. Missing kernel support?' help '(null)'
>> --
>>
>> ...but I was running without a hypervisor, so I tried the same kernel on a
>> PowerVM-virtualized system and the "hv_24x7" messages went away, but the
>> "nest" messages returned.  This may all be expected behavior... I confess
>> I haven't followed these new perf capabilities closely.
>>
> 
> Hi Paul/John,
>     This is something expected. For nest-imc we need bare-metal system and for
> hv-24x7 we need VM environment. Since you are checking this test in VM machine,
> there nest events are not supported and hence we are getting this error.
> 
> Thanks,
> Kajol Jain

Cool, so I hope that tested-by or similar can be provided :) [obviously 
pending any changes that come from reviews]

Thanks

> 
>> It's extremely likely that none of these errors has anything to do with your
>> changes. :-
>>
>> PC
>>
> .
>