Re: [PATCH v3 03/13] Attach/detach SoftiWarp to/from network and RDMA subsystem

Jason Gunthorpe
2018-01-23T16:43:16Z

On Tue, Jan 23, 2018 at 10:33:48AM -0600, Steve Wise wrote:

> > +/* Restrict usage of GSO, if hardware peer iwarp is unable to process
> > + * large packets. gso_seg_limit = 1 lets siw send only packets up to
> > + * one real MTU in size, but severly limits maximum bandwidth.
> > + * gso_seg_limit = 0 makes use of GSO (and more than doubles throughput
> > + * for large transfers).
> > + */
> > +const int gso_seg_limit;
> > +
>
> The GSO configuration needs to default to enable interoperation with all
> vendors (and comply with the RFCs). So make it 1 please.

The thing we call GSO in the netstack should be totally transparent on
the wire, so at the very least this needs some additional elaboration.

> Jason, would configfs be a reasonable way to allow tweaking these globals?

Why would we ever even bother to support a mode that is non-conformant
on the wire? Just remove it..

Jason