lkml.org 
[lkml]   [2013]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v4] sched: fix init NOHZ_IDLE flag
From
2013/2/22 Vincent Guittot <vincent.guittot@linaro.org>:
> I wanted to avoid having to use the sd pointer for testing NOHZ_IDLE
> flag because it occurs each time we go into idle but it seems to be
> not easily feasible.
> Another solution could be to add a synchronization step between
> rcu_assign_pointer(dom 1, NULL) and create new domain to ensure that
> all pending access to old sd values, has finished but this will imply
> a potential delay in the rebuild of sched_domain and i'm not sure
> that it's acceptable

The other issue is that we'll need to abuse the fact that struct
sched_domain is per cpu in order to store a per cpu state there.
That's a bit ugly but at least safer.

Also, are struct sched_group and struct sched_group_power shared among
several CPUs or are they per CPUs allocated as well? I guess they
aren't otherwise nr_cpus_busy would be pointless.


\
 
 \ /
  Last update: 2013-02-26 15:01    [W:0.042 / U:0.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site