Re: [PATCH RFC V2 2/2] net: Optimize snmp stat aggregation by walking all the percpu data at once

[David Miller]

From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
Date: Fri, 28 Aug 2015 12:09:52 +0530

> On 08/28/2015 12:08 AM, David Miller wrote:
>> From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
>> Date: Wed, 26 Aug 2015 23:07:33 +0530
>>
>>> @@ -4641,10 +4647,12 @@ static inline void __snmp6_fill_stats64(u64
>>> *stats, void __percpu *mib,
>>>   static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int
>>>   attrtype,
>>>   			     int bytes)
>>>   {
>>> +	u64 buff[IPSTATS_MIB_MAX] = {0,};
>>> +
 ...
> hope you wanted to know the overhead than to change the current
> patch. please let me know..

I want you to change that variable initializer to an explicit memset().

The compiler is emitting a memset() or similar _anyways_.

Not because it will have any impact at all upon performance, but because
of how it looks to people trying to read and understand the code.
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