netdev - Re: cat /proc/net/tcp takes 0.5 seconds on x86

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Message-ID: <48B5196A.2080502@hhs.nl>
Date:	Wed, 27 Aug 2008 11:07:54 +0200
From:	Hans de Goede <j.w.r.degoede@....nl>
To:	Herbert Xu <herbert@...dor.apana.org.au>
CC:	dada1@...mosbay.com, davej@...hat.com, netdev@...r.kernel.org
Subject: Re: cat /proc/net/tcp takes 0.5 seconds on x86_64

Herbert Xu wrote:
> Hans de Goede <j.w.r.degoede@....nl> wrote:
>> Eric Dumazet wrote:
>>
>>> # dmesg | grep "TCP established hash"
>>> TCP established hash table entries: 262144 (order: 10, 4194304 bytes)
>>> # time cat /proc/net/tcp >/dev/null
>>>
>>> real    0m0.091s
>>> user    0m0.001s
>>> sys     0m0.090s
>> As quoted above my idle x86_64, using the exact same hash table size, running 
>> 2.6.27-rc2.git1 uses 0.520 seconds for that same command, thats a difference of 
>> more then a factor 50 !!
> 
> That looks like a factor of 5 to me, not 50.
> 

Erm, you are completely right ofcourse.

Regards,

Hans
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