lkml.org 
[lkml]   [2009]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [patch 8/9] Documentation: Fix invalid rcu assumptions
On Fri, Dec 11, 2009 at 09:28:25PM +0000, Arnd Bergmann wrote:
> On Thursday 10 December 2009 00:53:26 Thomas Gleixner wrote:
> > Index: linux-2.6-tip/Documentation/credentials.txt
> > ===================================================================
> > --- linux-2.6-tip.orig/Documentation/credentials.txt
> > +++ linux-2.6-tip/Documentation/credentials.txt
> > @@ -408,9 +408,6 @@ This should be used inside the RCU read
> > ...
> > }
> >
> > -A function need not get RCU read lock to use __task_cred() if it is holding a
> > -spinlock at the time as this implicitly holds the RCU read lock.
> > -
> > Should it be necessary to hold another task's credentials for a long period of
> > time, and possibly to sleep whilst doing so, then the caller should get a
> > reference on them using:
>
> How about changing the documentation to explain why you can't just use a spinlock
> or local_irq_disable instead of rcu_read_lock? You explained it well in your
> [patch 0/9], but that part had not occurred to me yet and having it in the kernel
> sources might prevent more people from getting it wrong in the future.

That does make a lot of sense... Will add that in.

Thanx, Paul


\
 
 \ /
  Last update: 2009-12-11 23:03    [W:0.422 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site