Re: [PATCH] tcp: splice as many packets as possible at once

David Miller
2009-01-19T03:28:26Z

From: Willy Tarreau <w@1wt.eu>
Date: Mon, 19 Jan 2009 01:42:06 +0100

> Hi guys,
>
> On Thu, Jan 15, 2009 at 03:54:34PM -0800, David Miller wrote:
> > From: Willy Tarreau <w@1wt.eu>
> > Date: Fri, 16 Jan 2009 00:44:08 +0100
> >
> > > And BTW feel free to add my Tested-by if you want in case you merge
> > > this fix.
> >
> > Done, thanks Willy.
>
> Just for the record, I've now re-integrated those changes in a test kernel
> that I booted on my 10gig machines. I have updated my user-space code in
> haproxy to run a new series of tests. Eventhough there is a memcpy(), the
> results are EXCELLENT (on a C2D 2.66 GHz using Myricom's Myri10GE NICs) :
>
> - 4.8 Gbps at 100% CPU using MTU=1500 without LRO
> (3.2 Gbps at 100% CPU without splice)
>
> - 9.2 Gbps at 50% CPU using MTU=1500 with LRO
>
> - 10 Gbps at 20% CPU using MTU=9000 without LRO (7 Gbps at 100% CPU without
> splice)
>
> - 10 Gbps at 15% CPU using MTU=9000 with LRO

Thanks for the numbers.

We can almost certainly do a lot better, so if you have the time and
can get some oprofile dumps for these various cases that would be
useful to us.

Thanks again.