On 21 April 2011 11:11, Shawn Guo <shawn.guo@xxxxxxxxxxxxx> wrote: > On Thu, Apr 21, 2011 at 10:46:18AM +0200, Per Forlin wrote: >> On 21 April 2011 08:29, Shawn Guo <shawn.guo@xxxxxxxxxxxxx> wrote: >> > On Wed, Apr 20, 2011 at 05:30:22PM +0200, Per Forlin wrote: >> > [...] >> >> Remove dma_map and dma_unmap from your host driver and run the tests >> >> (obviously nonblocking and blocking will have the same results). If >> >> there is still no performance gain the cache penalty is very small on >> >> your platform and therefore nonblocking doesn't improve things much. >> >> Please let me know the result. >> >> >> > Sorry, I could not understand. What's the point to run the test when >> > the driver is even broken. The removal of dma_map_sg and >> > dma_unmap_sg makes mxs-mmc host driver broken. >> The point is only to get a measurement of the cost of handling >> dma_map_sg and dma_unmap_sg, this is the maximum time mmc nonblocking >> can save. >> The nonblocking mmc_test should save the total time of dma_map_sg and >> dma_unmap_sg, if the pre_req and post_req hooks are implemented >> correctly. >> Running without dma_map_sg and dma_unmap_sg will confirm if the >> pre_req and post_req hooks are implemented correctly. >> > With dma_map_sg and dma_unmap_sg removed, the mmc_test gave very low > numbers, though blocking and non-blocking numbers are same. Is it > an indication that pre_req and post_req hooks are not implemented > correctly? I think you could get the same numbers for the nonblocking with dma_map and dma_unmap in place. > If yes, can you please help to catch the mistakes? I will take a look. > -- > Regards, > Shawn > > Regards, Per -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
