lkml.org 
[lkml]   [2018]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 1/3] locking: Document the semantics of spin_is_locked()
On Tue, Apr 03, 2018 at 02:52:33PM +0100, David Howells wrote:
> Andrea Parri <andrea.parri@amarulasolutions.com> wrote:
>
> > > It's more complicated than that. This function is dangerous and should be
> > > used with extreme care. In the case where CONFIG_SMP=n the value is locked
> > > one way or the other and it might be the wrong way.
> >
> > You mean "unlocked"? (aka, return 0)
>
> No, I mean "fixed", sorry. We've had problems stemming from this before on UP
> systems.

Oooh... I had forgotten about spinlocks disappearing on UP systems,
good catch!

Suggestions for a fix? Clearly great care is required when using it
in things like WARN_ON()...

Thanx, Paul

\
 
 \ /
  Last update: 2018-04-03 16:17    [W:0.164 / U:4.912 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site