Machine: Sony VAIO VPCSB2C5E Processor: Intel(R) Core(TM) i5-2520M CPU using pm-suspend with /sys/power/pm_test set to freezer,devices and platform succeed even when repeating the test several times. When set to "processors" the machine hangs, although I'm not sure if it hangs during suspend or resume. Sysrqs keys does not work either after the hang. After disabling all processors but cpu0 suspend worked reliably. I'm available to do deeper debugging, if needed. Currently I don't know where to start.
Probably related, I did this after a fresh boot: sudo bash -c "echo 0 > /sys/devices/system/cpu/cpu1/online" sudo bash -c "echo 1 > /sys/devices/system/cpu/cpu1/online" sudo bash -c "echo 0 > /sys/devices/system/cpu/cpu1/online" The last command hangs, the system is responsive but it never returns. Any idea about how to debug this?
I've spent some time debugging the issue. Using printks I have been able to find out that the hang happens in the method called cpu_stop_cpu_callback And exactly in the case CPU_POST_DEAD inside the switch. The call to kthread_stop never returns. At this point I don't think that ACPI is the proper component to report the bug in. Any suggestion about a more proper place? Also any hint on how to move forward in the investigation is very welcome.
Please find the proposed fix here - http://permalink.gmane.org/gmane.linux.kernel/1038828
Hi Alessandro, Can you please report if the fix mentioned by Rex can solve your problem? Thanks.
ping