On Tue, Oct 25, 2016 at 07:23:27PM -0700, Michael Zoran wrote: > The original arm implementation uses dmac_map_area which is not > portable. Replace it with an architecture neutral version > which uses dma_map_sg. > > As you can see that for larger page sizes, the dma_map_sg > implementation is faster then the original unportable dma_map_area > implementation. > > Test dmac_map_area dma_map_page dma_map_sg > vchiq_test -b 4 10000 51us/iter 76us/iter 76us > vchiq_test -b 8 10000 70us/iter 82us/iter 91us > vchiq_test -b 16 10000 94us/iter 118us/iter 121us > vchiq_test -b 32 10000 146us/iter 173us/iter 187us > vchiq_test -b 64 10000 263us/iter 328us/iter 299us > vchiq_test -b 128 10000 529us/iter 631us/iter 595us > vchiq_test -b 256 10000 2285us/iter 2275us/iter 2001us > vchiq_test -b 512 10000 4372us/iter 4616us/iter 4123us > > For message sizes >= 64KB, dma_map_sg is faster then dma_map_page. > > For message size >= 256KB, the dma_map_sg is the fastest > implementation. > > "Normal" messages sizes should be about 1MB which is beyond > the length that this change shows a speed increase. > > This is v2 of the patch which includes extra WARN_ONs and > incorporates feedback from Eric Anholt <eric@xxxxxxxxxx>. > > Signed-off-by: Michael Zoran <mzoran@xxxxxxxxxxxx> > --- > .../interface/vchiq_arm/vchiq_2835_arm.c | 152 +++++++++++++-------- > 1 file changed, 93 insertions(+), 59 deletions(-) Nice work! I'd like to get an ack from Eric before applying it... thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
