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

From	Christophe Leroy <christophe.leroy@c-s.fr>
Newsgroups	linux.kernel
Subject	Re: [PATCH 4/9] powerpc: inline ip_fast_csum()
Date	2016-02-29 08:30 +0100
Message-ID	<r7qrg-8lp-7@gated-at.bofh.it> (permalink)
References	<qbwTD-86z-5@gated-at.bofh.it> <qbwTD-86z-3@gated-at.bofh.it> <qbL6i-3l0-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw


Le 23/09/2015 07:43, Denis Kirjanov a écrit :
> On 9/22/15, Christophe Leroy <christophe.leroy@c-s.fr> 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

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

Re: [PATCH 4/9] powerpc: inline ip_fast_csum() Christophe Leroy <christophe.leroy@c-s.fr> - 2016-02-29 08:30 +0100

csiph-web