On Monday 06 April 2009, Paul Walmsley wrote: > > Puzzle: get a dma_copypage() to work faster than copy_page(). > > Or a dma_clear_page() faster than clear_page(). Not easy... > > Doing it via the DMA engine may save power, since MPU can sleep.
But the CPU overhead of calling the DMA engine can exceed that of the memcpy()/memset() ... ;) Another concern is cache impact. In some cases, having the dirty data in dcache is a big win. With DMA, the cache will have been purged. It'd be nice to see DMA versions of this stuff winning; all I'm saying is that such wins are hard to achieve. - Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
