Re: [PATCH v15 11/11] RFC: fw_cfg: do DMA read operation

[Michael S. Tsirkin]

On Wed, Feb 28, 2018 at 05:00:58PM +0100, Marc-André Lureau wrote:
> Hi
> 
> On Wed, Feb 28, 2018 at 4:48 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> > On Wed, Feb 28, 2018 at 04:41:51PM +0100, Marc-André Lureau wrote:
> >> I don't know if it's always safe to enable dma in read_raw(), how
> >> could we know? Is there a check we could use to choose one or ther
> >> other (and thus avoiding explicit dma/readfn argument)?
> >
> > I'm not sure - but does it really matter? Is anyone reading large files
> > like this in production where speed matters?
> > Why even bother with DMA?
> 
> The difference is quite significante for not so small files, as shown above.
> 
> And if they access the fw_cfg entries at boot time, or when starting
> things etc, this may speed things up.

Question would be whether anyone at all does this.

-- 
MST