Re: [PATCH v2] proc: speedup /proc/stat handling

[JÃrg-Volker Peetz]

Eric Dumazet wrote, on 01/25/12 01:26:
> Le mercredi 25 janvier 2012 Ã 09:18 +0900, KAMEZAWA Hiroyuki a Ãcrit :
> 
>> BTW, what is the reason of this change ?
>>
>>> -	unsigned size = 4096 * (1 + num_possible_cpus() / 32);
>>> +	unsigned size = 1024 + 128 * num_possible_cpus();
>>
>> I think size of buffer is affected by the number of online cpus.
>> (Maybe 128 is enough but please add comment why 128 ?)
>>
> 
> There is no change, as 4096/32 is 128 bytes per cpu.
> 

Wrong math, only num_possible_cpus() is divided by 32. Thus,

-	unsigned size = 4096 * (1 + num_possible_cpus() / 32);
+	unsigned size = 4096 + 128 * num_possible_cpus();

<snip>
-- 
Best regards,
JÃrg-Volker.

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