Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port

From: Grygorii Strashko
Date: Fri Jan 22 2016 - 13:22:17 EST

hi Sebastian,
On 01/22/2016 05:04 PM, Grygorii Strashko wrote:
On 01/22/2016 04:14 PM, Sebastian Andrzej Siewior wrote:
On 01/22/2016 02:34 PM, Grygorii Strashko wrote:
Do you still see it with the missing lazy bits? I don't see where this
could come from.

yep. I've tried it with and without changing _TIF_WORK_MASK
Seems It's triggered by Virtual terminal keyboard_tasklet

Just bootet my current v4.4 to cross check what you see and I have this:

[ 3.808273] clocksource: Switched to clocksource arch_sys_counter
[ 3.851193] keyboard: kbd_init(1609)
[ 3.861903] keyboard: kbd_bh(1201)
[ 3.868322] keyboard: kbd_init(1612)
[ 3.868581] NET: Registered protocol family 2

So. No backtrace here. According to the full dmesg I should have all
CPUs up by now. kbd_bh is comming from ksoftirqd as well. No idea why
you see this.
There is a irq off region which sets and removes RUN bit, I have no
idea why you have this backtrace.

As of now, i'm too :(
- not sure if this could be the case, but my kernel is !SMP
# CONFIG_SMP is not set
# CONFIG_CPUSETS is not set

Sorry, this is false alarm - I did mistake in my patch.

Sorry for your time.