On di, 22 okt 2019 14:58:42 -0500, Elenita Hinds wrote: > Sorry for the delay. Responses below .. > > On Thu, Oct 17, 2019 at 4:16 PM Kurt Van Dijck > <dev.kurt@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > Hey, > > > > On do, 17 okt 2019 15:37:04 -0500, Elenita Hinds wrote: > > > I pulled in the c_can patches from the for-kurt branch (63574e9 thru > > > bf01f717) and tested on my device. > > > The number of overruns are noticeably fewer; however, the overall > > > system performance seems to have slowed down. For example, > > > the console response and Bluetooth data rate are noticeably slower. > > > > You now give more precedence to CAN and less to console etc. ? > > > > [eh] No. The priorities are the same or however Linux handles > interrupt priorities. > > > > I also noticed that while the number of overruns decreased, the number > > > of errors increased: > > > > You have an interesting setup. I suspect that the FIFO is filled, and > > does drop messages, although that is recorded in the statistics? > > > > Would you want to try branch c_can-v4.9 in github.com/kurt-vd/linux? > > I improved the reception a bit, and increased the FIFO size. > > [eh] I pulled the c_can-v4.9 changes (delta from v4.9) and the > behavior is the same -- > the number of overruns is reduced (about 0.011% loss compared to about > 0.32%) but the number > of errors is increased (used to be the same number as the overruns). Did you look for CAN bus errors yet? $ ip link set can0 type can berr-reporting $ ip link set can0 up and then $candump -e any,0~0,#FFFFFFFF If you experience bus problems, the cpu may have troubles following them. > I still see a slight degradation > in system performance. > I also tried the c_can-more-objects branch (increased the message > objects to 64) and this also > improved CAN handling (about to 0.004% overruns). > Then I combined both IRQ-rxoffload and more-objects changes together > and the number of overruns > is further reduced (loss is close to 0%). That is good news for me. I'll grab the 'more-objects' branch also. Where did you get it? > > > Besides that, can you give more details about your system and your load? > > [eh] System is similar to Beagleboard Black: TI AM335x. > From 'top', running about 0% idle, with sys about 44%, usr about 43%, > sirq about 9%. > Load average: 4.70 4.88 4.04 > Let me know if you need more info. > > > > > Kind regards, > > Kurt
