[openib-general] Performance Degradation with OFED v. Voltaire

[Or Gerlitz]

Philippe, can you try this patch, i have problems with setting a 
compilation env now but it should work.

unpack OFED 1.1, copy this to 
OFED-1.1/openib-1.1/kernel_patches/fixes/xxx_cma_tavor_quirk.txt
and then pack OFED 1.1 and rebuild

Or.

> Index: openib-1.1/drivers/infiniband/core/cma.c
> ===================================================================
> --- openib-1.1.orig/drivers/infiniband/core/cma.c       2006-12-18 13:27:45.213587734 +0200
> +++ openib-1.1/drivers/infiniband/core/cma.c    2006-12-18 13:34:24.921455159 +0200
> @@ -1117,6 +1117,9 @@ static void cma_query_handler(int status
>         route = &work->id->id.route;
> 
>         if (!status) {
> +               /* XXX - if returned path MTU is 2K force it to be 1K */
> +               if(path_rec->mtu == IB_MTU_2048)
> +                       path_rec->mtu = IB_MTU_1024;
>                 route->num_paths = 1;
>                 *route->path_rec = *path_rec;
>         } else {