lkml.org 
[lkml]   [2018]   [Jun]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4/4] kthread: Simplify kthread_park() completion
On Fri, Jun 08, 2018 at 11:52:20AM +0200, Oleg Nesterov wrote:
> in smpboot_update_cpumask_percpu_thread() can hit a KTHREAD_SHOULD_PARK
> thread? Lets look into kernel test robot's .config:
>
> CONFIG_NR_CPUS=1
>
> Now look at NR_CPUS==1 version of for_each_cpu* helpers:
>
> #define for_each_cpu(cpu, mask) \
> for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)

Argh, that issue again.

> So even if the "tmp" cpumask is empty the code above always does
>
> smpboot_park_thread(plug_thread, 0);
>
> and hits the already parked kthread.

OK, I'll write a new Changelog.

\
 
 \ /
  Last update: 2018-06-12 14:43    [W:0.044 / U:3.164 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site