lkml.org 
[lkml]   [2017]   [May]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC][PATCH 2/5] cpu-hotplug: Allow get_online_cpus() to nest
On Sat, 13 May 2017 00:15:03 +0200 (CEST)
Thomas Gleixner <tglx@linutronix.de> wrote:

> On Fri, 12 May 2017, Steven Rostedt wrote:
> > void get_online_cpus(void)
> > {
> > +#ifdef CONFIG_LOCKDEP
> > + if (current->goc_depth++)
> > + return;
>
> This must be unconditional and not depend on lockdep. The percpu rwsem is
> going to deadlock silently otherwise when a writer is waiting ....
>

After I sent the updated changes to Paul, I realized this. But didn't
update it as I turned my attention to seeing if we can still get it
done without it.

But I'm not convinced that we can yet. I'll reply to Peter's email
again later.

-- Steve

\
 
 \ /
  Last update: 2017-05-13 02:24    [W:0.107 / U:0.980 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site