On Wed, Nov 11, 2015 at 12:37:54PM +0200, Peter Ujfalusi wrote: > Hi, > > The first two patch is trivial fix. > The third (remove the tasklet use for starting the transfer): > I had been wondering about this for a while and now I was able to spend some > time to look at this in more detail. > In 'normal' operation I have never seen the tasklet to start more then one > transfer even when pushing I/O based workloads on the board. However when I run > the DMAtest module I can see that the tasklet executes about 15 transfers. > When the tasklet use has been removed, everything worked as well as before but > the throughput of MMC/SD and memcpy increased slightly: > > dd if=/dev/mmcblk0 of=/dev/null bs=64k count=24000 > ~16.5 MB/s -> ~16.6 MB/s > > echo 6553 > /sys/module/dmatest/parameters/test_buf_size > echo 2000 > /sys/module/dmatest/parameters/timeout > echo 5000 > /sys/module/dmatest/parameters/iterations > ~585 KB/s -> ~638 KB/s > > It worth mentioning that _with_ the tasklet starting the transfers I managed to > hit a situation once when for some reason the memcpy tests were started to time > out. This happend with memcpy, iozone, dd and grep -R blabla /usr/ running at > the same time. > > The last patch is to correct the behaviour of omap-dma when short memcpy is used > by a client and the client is not using completion, but polling for the end of > the transfer. Applied, thanks -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
