Re: [PATCH 7/8] [PATCH] dynamic calculation of event message size for ctnetlink

[Pablo Neira Ayuso <pablo@netfilter.org>]

Patrick McHardy wrote:
> Pablo Neira Ayuso wrote:
>> Pablo Neira Ayuso wrote:
>>> Patrick McHardy wrote:
>>>> These calculations look somewhat expensive to perform for every
>>>> message.
>>>> Do you have any numbers for this new patch that shows the difference
>>>> in CPU usage compared to the resizing done by af_netlink.c?
>>> Fabian Hugelshofer reported some reduction (~5%) on an embedded
>>> environment but he was using top to measure the difference. I'll collect
>>> some more trustable data and get back to you.
>>
>> Some oprofile results:
>>
>> wo/patch
>> 2189      0.0305  nf_conntrack_netlink.ko  nf_conntrack_netlink
>> ctnetlink_conntrack_event
>>
>> w/patch
>> 2302      0.0440  nf_conntrack_netlink.ko  nf_conntrack_netlink
>> ctnetlink_conntrack_event
>>
>> While __alloc_skb and netlink_broadcast report similar values for w/ and
>> wo/ the patch.
> 
> So its actually getting worse? :) Any other differences, like less
> cycles for memcpy in netlink_trim()?

netlink_trim is inlined, so it is included in netlink_broadcast, and
there's no improve in memcpy nor netlink_broadcast. I'm going to repeat
all the test to check if I'm doing something wrong, until that, let's
keep it back.

-- 
"Los honestos son inadaptados sociales" -- Les Luthiers