[openib-general] Re: [PATCH] [RFC] use device max_map_per_fmr in fmr pool

[Michael S. Tsirkin]

Quoting r. Or Gerlitz <ogerlitz at voltaire.com>:
> I am not on working on performance optimizations now, the code we wrote 
> to the GEN1 driver was using the max possible remaps and i'd like to 
> work here this way as well.

But why make changes if this doesnt gain performance?

> >Allocating resources up to a maximum supported by a device is rarely 
> >optimal.
> >Its easy to imagine a device where FMR number of maps is a shared resource,
> >so allocating one FMR with max_map_per_fmr will not let you create any more
> >of these.
> 
> Why imagine something related to Mellanox proprietary implementation 
> over which the number of times you remap an FMR does not consume --any-- 
> further resources on the device other (at least for tavor and arbel, 
> correct if i am wrong to other devices).

Fair enough.

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies