[openib-general] Re: PATCH] mthca - command interface - revised

[Michael S. Tsirkin]

Quoting r. Roland Dreier <rdreier at cisco.com>:
> Subject: Re: PATCH] mthca - command interface - revised
> 
>     Eli> Roland, this patch is modified according to your comments. It
>     Eli> also adds a kernel configuration option which selects whether
>     Eli> to use posting commands through doorbells. The option is off
>     Eli> by default.
> 
> Why make a config option?  Is there any reason why someone would want
> to disable this feature, assuming the firmware supports it?

AFAIK, which of the two options gives better performance might depend
on the application and the specific system.
For now, Eli made the simpler option the default.

> If there is some reason to turn this off, then a module parameter
> would make more sense to me -- otherwise a kernel config option means
> that a recompile is necessary to change the setting, and distros won't
> ship drivers with the option turned on.
> 
>  - R.

Good idea.

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies