Victor On Tue, Mar 8, 2016 at 9:05 AM, Victor Dodon <printesoi@xxxxxxxxxxxx> wrote: > > Hi all, > > I have some performance issues with the host port on a Beaglebone > board. I tested with kernel 3.8.13, 3.14.55 and 4.1.18 and the issue > still persists. Running a fio test with 64k random reads from a USB > flash drive yields a maximum of 14402.01 KiB/s (115216.08 Kb/s). The > 3.14 and 4.1 kernels where build with CONFIG_TI_CPPI41_DMA=y. I was > able to get a much better performance on the client USB port by > enabling fifo double buffering. Iperf over a gigabit connection and a Ethernet > to USB adapter plugged in the host port gives a maximum of 180Mbit/s with fifo > double buffering enabled for the ep1 and ep2. Do you have answer for the following - What is the raw throughput of musb driver ? ( With no class driver) - What is the performance you are expecting ? performance of MSC depends on storage medium as well. May be you should use high performance storage device - For Ethernet, did you try NCM ? I believe that gives better results With little bit of experience in musb, I have seen only similar performances in 3.0 Kernel. Any tweaks for improvement would help the community. > > Are there any known performance issues in the musb driver? For my use > case I need > a higher bandwidth and I would like to improve the host controller, > but I'm a beginner in Kernel hacking and I would appreciate some help, > tips or any cues to start. > > I also found a few problems with the host port. For example: > Using the setup described above (gigabit connection and a Ethernet > to USB adapter plugged in the host port and with a running iSCSI > initiator on the BB, > in usb/musb/musb_core.c if I change mode_4_cfg to enable double > buffering, and I restart the board while doing a dd from the disk > mounted with iSCSI, the kernel stops at: > > > Kind regards, > Victor Dodon. > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
