On 03/15/2018 02:27 AM, Adrian Hunter wrote: > Please try: > > perf record -a -e mmc:* -- bonnie++ -u root -r 256 -s 512 -x 1 -d /mnt > > and share the resulting perf.data file when you are able > to reproduce the hung task message. > > You may want to add this patch first: > > https://marc.info/?l=linux-mmc&m=152110580324200 While this SoC has perf counters, Unfortunately the overflow interrupts are not wired up. We can do perf stats but not sampling. Peter was it you or Vince trying to use timer interrupts to emulate perf sampling on some ARM SoC ? Thing is we have a spare hardware timer per core (TIMER1) which is not usabel for otherwise gtod function in SMP and could well be repurposed for perf needs. -Vineet