Re: [Query] Preemption (hogging) of the work handler

From: Sergey Senozhatsky
Date: Tue Jul 12 2016 - 05:38:13 EST


On (07/11/16 15:35), Viresh Kumar wrote:
> Sometimes, the platform doesn't come back after suspend. I have tried
> enabling no-console-suspend and the last line it prints is:
> Disabling non-boot CPUs
> And nothing after that at all. We have to forcefully reboot the phone
> after that. Moving the prints to they synchronous way (using
> echo 1 > /sys/module/printk/parameters/synchronous), fixes that issue.

hm... I'll take a look.

> So, the asynchronous printing have a issue that only we are hitting.
> It looks like that all the CPUs are gone except CPU0 and that CPU is
> hogged by the printk thread to print stuff as well as to suspend the
> system, and something eventually gets wrong.