Re: Deactivating TCP checksumming

Dennis Cook (cook@sandgate.com)
Wed, 2 Apr 2003 15:47:35 -0500


What I was looking for is a general capability to keep the SW transport
stack from
computing outgoing TCP/UDP/IP checksums so that the HW can be allowed to do
it,
similar to Windows checksum offload capability.

"Jeff Garzik" <jgarzik@pobox.com> wrote in message
news:20030402203653.GA2503@gtf.org...
> On Wed, Apr 02, 2003 at 02:22:59PM -0500, Dennis Cook wrote:
> > Using RH Linux kernel 2.4.18, setting "features" bit NETIF_F_IP_CSUM
does
> > not appear
> > to keep a valid IP checksum from being computed in packets presented to
my
> > driver
> > for transmission. So having HW compute outgoing checksum buys nothing.
>
> You are not using sendfile(2), which is required to activate h/w csum.
>
> Jeff
>
>
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/