Re: [PATCH 08/24] net, diet: Make TCP metrics optional

From: Andi Kleen
Date: Wed May 07 2014 - 00:33:55 EST


On Tue, May 06, 2014 at 04:29:39PM -0700, Eric Dumazet wrote:
> On Tue, 2014-05-06 at 14:05 -0700, Andi Kleen wrote:
>
> > - Make GRO optional.
> > This is purely a performance feature for high bandwidth.
>
> Make this properly then, instead of relying on LTO.
>
> We did preliminary work to put this stuff in separate files, but its not
> complete yet.

FWIW doesn't matter for LTO.

>
> tcpv4_offload has pointers to tcp4_gro_receive() and tcp4_gro_complete()
>
> Is LTO smart enough to understand this will never be called, and do
> proper code elimination of whole _gro_ helpers ?

When there are pointers in static objects it cannot eliminate it for C
(it may work for C++)

However if you just remove the pointer it'll remove the rest.

-Andi

--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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