lkml.org 
[lkml]   [2019]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RFC tip/core/rcu 14/14] rcu/nohz: Make multi_cpu_stop() enable tick on all online CPUs
On Fri, Aug 02, 2019 at 08:15:01AM -0700, Paul E. McKenney wrote:
> The multi_cpu_stop() function relies on the scheduler to gain control from
> whatever is running on the various online CPUs, including any nohz_full
> CPUs running long loops in kernel-mode code. Lack of the scheduler-clock
> interrupt on such CPUs can delay multi_cpu_stop() for several minutes
> and can also result in RCU CPU stall warnings. This commit therefore
> causes multi_cpu_stop() to enable the scheduler-clock interrupt on all
> online CPUs.

This sounds wrong; should we be fixing sched_can_stop_tick() instead to
return false when the stop task is runnable?

\
 
 \ /
  Last update: 2019-08-04 16:45    [W:0.125 / U:0.312 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site