On 04/12/20 21:19, Qian Cai wrote: > On Tue, 2020-11-17 at 19:28 +0000, Valentin Schneider wrote: >> We did have some breakage in that area, but all the holes I was aware of >> have been plugged. What would help here is to see which tasks are still >> queued on that outgoing CPU, and their recent activity. >> >> Something like >> - ftrace_dump_on_oops on your kernel cmdline >> - trace-cmd start -e 'sched:*' >> <start the test here> >> >> ought to do it. Then you can paste the (tail of the) ftrace dump. >> >> I also had this laying around, which may or may not be of some help: > > Okay, your patch did not help, since it can still be reproduced using this, > > https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/hotplug/cpu_hotplug/functional/cpuhotplug04.sh > > # while :; do cpuhotplug04.sh -l 1; done >
Ok, can reproduce this on a TX2 on next-20201207. I didn't use your config, I oldconfig'd my distro config and only modified it to CONFIG_PREEMPT_NONE. Interestingly the BUG happens on CPU127 here too... I'll start digging.
