On Mon, Jun 27, 2011 at 11:42:52AM +0200, Per Forlin wrote: > Conclusion: > Working with mmc the relative cost of DSB is almost none. There seems > to be slightly higher number for mmc blocking requests with the DSB > patch compared to not having it.
These figures suggest that dsb is comparitively not heavy on the hardware you're testing. I think I'm going to apply the patch anyway - it certainly makes stuff no worse, and if someone has a platform where dsb is more expensive, then they should see a greater benefit from this change. The next thing to think about in DMA-land is whether we should total up the size of the SG list and choose whether to flush the individual SG elements or do a full cache flush. There becomes a point where the full cache flush becomes cheaper than flushing each SG element individually. _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
