Messages in this thread | | | Date | Tue, 5 Jul 2011 16:27:05 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH v4] mmc: documentation of mmc non-blocking request usage and design. |
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On Tue, 5 Jul 2011 23:35:32 +0200 Per Forlin wrote:
> +MMC block driver > +================ > + > +The issue_rw_rq() in the MMC block driver is made non-blocking. > +The increase in throughput is proportional to the time it takes to > +prepare (major part of preparations are dma_map_sg and dma_unmap_sg) > +a request and how fast the memory is. The faster the MMC/SD is > +the more significant the prepare request time becomes. Roughly the expected > +performance gain is 5% for large writes and 10% on large reads on a L2 cache > +platform. In power save mode, when clocks run on a lower frequency, the DMA > +preparation may cost even more. As long as these slower preparations are run > +in parallel with the transfer performance wont be affected.
won't
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
thanks. --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code ***
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