Re: [PATCH 4/9] powerpc: inline ip_fast_csum()

[Christophe Leroy]

Le 23/09/2015 07:43, Denis Kirjanov a Ãcrit :
> On 9/22/15, Christophe Leroy <christophe.leroy@xxxxxx> wrote:
> > In several architectures, ip_fast_csum() is inlined
> > There are functions like ip_send_check() which do nothing
> > much more than calling ip_fast_csum().
> > Inlining ip_fast_csum() allows the compiler to optimise better
> Hi Christophe,
> I did try it and see no difference on ppc64. Did you test with socklib
> with modified loopback and if so do you have any numbers?

Hi Denis,

I put a mftbl at start and end of ip_send_check() and tested on a MPC885:
* Without ip_fast_csum() inlined, approxymatly 7 TB ticks are spent in 
ip_send_check()
* With ip_fast_csum() inlined, approxymatly 5,4 TB ticks are spent in 
ip_send_check()

So it is about 23% time reduction.

Christophe