Messages in this thread | | | From | Marc-André Lureau <> | Date | Wed, 28 Feb 2018 17:00:58 +0100 | Subject | Re: [PATCH v15 11/11] RFC: fw_cfg: do DMA read operation |
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Hi
On Wed, Feb 28, 2018 at 4:48 PM, Michael S. Tsirkin <mst@redhat.com> 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.
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