linux-kernel - Re: [PATCH V2 drivers/perf: hisi:] drivers/perf: hisi: fix set wrong filter mode for running events issue

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Message-ID: <84eacd1e-f259-4428-f722-f61695ede3ee@huawei.com>
Date:   Mon, 4 Sep 2023 11:10:02 +0800
From:   "chenhao (EZ)" <chenhao418@...wei.com>
To:     Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        Jijie Shao <shaojijie@...wei.com>
CC:     <will@...nel.org>, <mark.rutland@....com>,
        <yangyicong@...ilicon.com>, <shenjian15@...wei.com>,
        <wangjie125@...wei.com>, <liuyonglong@...wei.com>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH V2 drivers/perf: hisi:] drivers/perf: hisi: fix set wrong
 filter mode for running events issue



On 2023/9/1 18:11, Jonathan Cameron wrote:
> On Fri, 1 Sep 2023 11:50:27 +0800
> Jijie Shao <shaojijie@...wei.com> wrote:
> 
>> From: Hao Chen <chenhao418@...wei.com>
> 
> Mention which hisi pmu this is in the patch description (hns)
> 
>>
>> hns3_pmu_select_filter_mode() includes A series of mode judgments such
> 
> includes a series
> 
>> as global mode ,function mode, function-queue mode, port mode, port-tc
>> mode.
>>
>> For a special scenario:
>> command use parameter
>> perf stat -a -e hns3_pmu_sicl_0/bdf=0x3700,config=0x3,queue=0x0,
>> and hns3_pmu_is_enabled_func_mode() has a judgement as below:
>> if (!(pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC))
>>
>> filter_support of event 0x3 hasn't set bit for func mode, so it can't
>> enter func-mode branch, and continue to func-queue mode judgement, port
>> judgement, port-tc mode, then enter port-tc mode.
>>
>> It's not up to expectations, it shouldn't enter any modes but
>> return -ENOENT.
>>
>> port-tc mode parameter show as below:
>> perf stat -a -e hns3_pmu_sicl_0/config=0x00001,port=0x0,tc=0x1
>>
>> port-tc mode should use bdf parameter as 0, so, add judgement of
>> bdf parameter to fix it.
> 
> I don't follow the description here.  As far as I can see from the code
> the change just checks that BDF is not set before allowing a port based
> filter.

Thanks for review.

Maybe I don't think about it completely.

For this patch, I only consider this scenario mentioned in patch and exactly filter out
port based mode, then enter port-tc based mode.

Actually port based mode also need this change for other scenarios, do you agree with it?

> 
>>
>> Signed-off-by: Hao Chen <chenhao418@...wei.com>
>> Signed-off-by: Jijie Shao <shaojijie@...wei.com>
>> ---
>> changeLog:
>>   v2: add more details in log message suggested by Will
>>   v1 link: https://lore.kernel.org/all/20230816094619.3563784-1-shaojijie@huawei.com/
>> ---
>>  drivers/perf/hisilicon/hns3_pmu.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/perf/hisilicon/hns3_pmu.c b/drivers/perf/hisilicon/hns3_pmu.c
>> index e0457d84af6b..2aa9cb045705 100644
>> --- a/drivers/perf/hisilicon/hns3_pmu.c
>> +++ b/drivers/perf/hisilicon/hns3_pmu.c
>> @@ -998,12 +998,13 @@ static bool
>>  hns3_pmu_is_enabled_port_tc_mode(struct perf_event *event,
>>  				 struct hns3_pmu_event_attr *pmu_event)
>>  {
>> +	u16 bdf = hns3_pmu_get_bdf(event);
>>  	u8 tc_id = hns3_pmu_get_tc(event);
>>  
>>  	if (!(pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_PORT_TC))
>>  		return false;
>>  
>> -	return tc_id != HNS3_PMU_FILTER_ALL_TC;
>> +	return (tc_id != HNS3_PMU_FILTER_ALL_TC) && (!bdf);
> 
> No need for brackets on !bdf
> 
>>  }
>>  
>>  static bool
> 
> .
>