Re: [net-next][PATCH 11/13] RDS: IB: add Fastreg MR (FRMR) detection support

[santosh shilimkar]

On 2/22/2016 7:38 AM, Bart Van Assche wrote:
> On 02/21/16 19:36, David Miller wrote:
> > From: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
> > Date: Sat, 20 Feb 2016 03:30:02 -0800
> >
> > > @@ -54,6 +55,8 @@ module_param(rds_ib_mr_8k_pool_size, int, 0444);
> > >   MODULE_PARM_DESC(rds_ib_mr_8k_pool_size, " Max number of 8K mr per
> > > HCA");
> > >   module_param(rds_ib_retry_count, int, 0444);
> > >   MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before
> > > reporting an error");
> > > +module_param(prefer_frmr, bool, 0444);
> > > +MODULE_PARM_DESC(prefer_frmr, "Preferred MR method if both FMR and
> > > FRMR supported");
> >
> > Sorry, you're going to have to create a real run time method to configure
> > this parameter.
> >
> > I'm strongly against module parameters.
> >
> > Please don't go into details about why this might be difficult to do,
> > I'm totally not interested.  Doing things properly is sometimes not
> > easy, that's life.
Sure Dave. Will drop the parameter. The runtime detection is already
in place. When an HCA hardware supports both FMR and FRMR features,
parameter can be used as over-ride over a default selection.

> Hello Santosh,
>
> What is the purpose of the prefer_frmr kernel module parameter ? Is this
> a parameter that is useful to RDS users or is its only purpose to allow
> developers of the RDS module to test both the FMR and FRMR code paths on
> hardware that supports both MR methods ?
Right. Since FRMR in early phase still for RDS, it was useful on HCA's
which supports both registration methods. Its not a deal breaker so
am going to drop the parameter as mentioned above.

Regards,
Santosh