Hello,
I’ve encountered a strange behavior with Xen on arm64 with regards to suspend/resume.
My setup:
Version:
Xen 4.13.1
Target: NXP imx8x SoC
We also use a set of patches from Aggios (https://xen-devel.narkive.com/yGps0HKG/rfc-v2-xen-arm-suspend-to-ram-support-in-xen-for-arm)
Occasionally xen gets stuck on resume. We know that the lower levels wake up and xen starts to resume because xen’s debug console
is available. When we’re in this state dom0 does not resume and both pCPU’s are in idle loops. If we at this point issue debug console commands (like ‘h’ for the help menu) that schedule tasklets dom0 wakes up and continues. Debug function that run in the
irq-handler does not have the same effect.
This is what the run queue looks like:
sched_smt_power_savings: disabled
NOW=490275382125
Online Cpus: 0-1
Cpupool 0:
Cpus: 0-1
Scheduler: SMP Credit Scheduler rev2 (credit2)
Active queues: 1
default-weight = 256
Runqueue 0:
ncpus = 2
cpus = 0-1
max_weight = 256
pick_bias = 1
instload = 1
aveload = 282294 (~107%)
idlers: 0
tickled: 0
fully idle cores: 0
Domain info:
Domain: 0 w 256 c 0 v 2
1: [0.0] flags=2 cpu=1 credit=984625 [w=256] load=208781 (~79%)
2: [0.1] flags=0 cpu=1 credit=9742375 [w=256] load=25693 (~9%)
Domain: 1 w 256 c 0 v 1
3: [1.0] flags=0 cpu=1 credit=10447250 [w=256] load=7835 (~2%)
Runqueue 0:
CPU[00] runq=0, sibling={0}, core={0}
CPU[01] runq=0, sibling={1}, core={1}
run: [0.0] flags=2 cpu=1 credit=-1543000 [w=256] load=208781 (~79%)
RUNQ:
0: [0.1] flags=0 cpu=1 credit=10275375 [w=256] load=25279 (~9%)
[t: display multi-cpu clock info]
Synced stime skew: max=125ns avg=125ns samples=1 current=125ns
Synced cycles skew: max=1 avg=1 samples=1 current=1
I would be grateful if I could get some hint’s on how to debug this.
Best Regards
Jonas
