On Wed, Oct 29, 2014 at 12:05:15PM +0200, Laurent Pinchart wrote: > Hi Geert, > > On Wednesday 29 October 2014 10:59:48 Geert Uytterhoeven wrote: > > On Wed, Oct 29, 2014 at 10:49 AM, Laurent Pinchart wrote: > > > I've performed quick SDHI performance tests yesterday. Read performance > > > were around 7.5% lower with DMA support. Write performances varied but > > > seemed similar on average. > > > > > > - PIO > > > > > > # time dd if=/dev/mmcblk1 of=/mnt/ram/mmc.bin count=32768 bs=4096 > > > 262144+0 records in > > > 262144+0 records out > > > > 262144 records? Did it get split in 512 byte records? > > I knew I should have replaced the whole results instead of copying only the > lines I thought had changed between tests :-) The times correspond to 32768 > blocks of 4kB despite what the number of records say. As discussed elsewhere, I've dropped the following two patches for now, pending further investigation of the problem. ARM: shmobile: r8a7791: Reference DMA channels in SDHI DT nodes ARM: shmobile: r8a7790: Reference DMA channels in SDHI DT nodes > > > # time dd of=/dev/mmcblk1 if=/mnt/ram/mmc.bin count=32768 bs=4096 > > > 32+0 records in > > > 32+0 records out > > > > Only 32 records? > > > > > - DMA > > > > > > # time dd if=/dev/mmcblk1 of=/mnt/ram/mmc.bin count=32768 bs=4096 > > > 32+0 records in > > > 32+0 records out > > > > Only 32 records? > > > > > # time dd of=/dev/mmcblk1 if=/mnt/ram/mmc.bin count=32768 bs=4096 > > > 32768+0 records in > > > 32768+0 records out > > > > OK > > -- > Regards, > > Laurent Pinchart > -- 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
