Messages in this thread | | | From | (Niels Möller) | Subject | Re: TCP_MAXSEG vs TCP/generic segmentation offload (tso/gso) | Date | Thu, 25 Nov 2010 17:25:42 +0100 |
| |
Eric Dumazet <eric.dumazet@gmail.com> writes:
> I believe TCP_MAXSEG is working fine, but GRO/GSO dont care at all : > They coalesce frames whatever their size is.
I was under the impression that TSO (and maybe GSO) implied more cleverness in the network card; that the network card more or less gets to decide by itself how to divide a tcp stream into segments. And for example in the atl1c driver which I looked a bit into, this was what the REG_MTU register was for. Seems I have gotten this totally wrong.
Maybe Documentation/networking/netdevices.txt could clarify how it works. Currently, it says
: Segmentation Offload (GSO, TSO) is an exception to this rule. The : upper layer protocol may pass a large socket buffer to the device : transmit routine, and the device will break that up into separate : packets based on the current MTU.
Regards, and thanks for your patience, /Niels
-- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. -- 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/
| |