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Message-ID: <4a6937b9-08b1-0f52-18db-13e17e344786@intel.com>
Date:   Tue, 6 Sep 2022 16:41:55 +0800
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Subject: Re: [PATCH v2 1/2] percpu: Add percpu_counter_add_local
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To:     Shakeel Butt <shakeelb@google.com>
Cc:     akpm@linux-foundation.org, vasily.averin@linux.dev,
        dennis@kernel.org, tj@kernel.org, cl@linux.com,
        ebiederm@xmission.com, legion@kernel.org, manfred@colorfullife.com,
        alexander.mikhalitsyn@virtuozzo.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, tim.c.chen@intel.com,
        feng.tang@intel.com, ying.huang@intel.com, tianyou.li@intel.com,
        wangyang.guo@intel.com, jiebin.sun@intel.com
References: <20220902152243.479592-1-jiebin.sun@intel.com>
 <20220905193516.846647-1-jiebin.sun@intel.com>
 <20220905193516.846647-3-jiebin.sun@intel.com>
 <20220905193159.eeu2xmqj6743kzxv@google.com>
From:   "Sun, Jiebin" <jiebin.sun@intel.com>
In-Reply-To: <20220905193159.eeu2xmqj6743kzxv@google.com>
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On 9/6/2022 3:31 AM, Shakeel Butt wrote:
> On Tue, Sep 06, 2022 at 03:35:16AM +0800, Jiebin Sun wrote:
>> Add percpu_counter_add_local for only updating local counter
>> without aggregating to global counter.
> Please add why do we need this. Who should use this and who shouldn't.

Thanks. I have added the code comment and change log in patch v3 and 
provided

the info who should use it and who shouldn't.

>
>> Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
> [...]
>
>> diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
>> index ed610b75dc32..d33cb750962a 100644
>> --- a/lib/percpu_counter.c
>> +++ b/lib/percpu_counter.c
>> @@ -72,6 +72,12 @@ void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
>>   }
>>   EXPORT_SYMBOL(percpu_counter_set);
>>
> Add a doc comment here on why someone want to use this?
>
>> +void percpu_counter_add_local(struct percpu_counter *fbc, s64 amount)
>> +{
>> +	this_cpu_add(*fbc->counters, amount);
>> +}
>> +EXPORT_SYMBOL(percpu_counter_add_local);
>> +
>>   /*
>>    * This function is both preempt and irq safe. The former is due to explicit
>>    * preemption disable. The latter is guaranteed by the fact that the slow path
>> -- 
>> 2.31.1
>>