lkml.org 
[lkml]   [2006]   [Sep]   [24]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateSun, 24 Sep 2006 14:44:40 -0700
FromAndrew Morton <>
SubjectRe: [-mm PATCH] RCU: debug sleep check
On Mon, 25 Sep 2006 03:05:08 +0530
Dipankar Sarma <dipankar@in.ibm.com> wrote:

> On Sun, Sep 24, 2006 at 11:56:46AM -0700, Andrew Morton wrote:
> > On Mon, 25 Sep 2006 00:05:09 +0530
> > Dipankar Sarma <dipankar@in.ibm.com> wrote:
> > 
> > > Add a debug check for rcu read-side critical section code calling
> > > a function that might sleep which is illegal. The check is enabled only
> > > if CONFIG_DEBUG_SPINLOCK_SLEEP is set.
> > > 
> > 
> > Does this actually change anything?  rcu_read_lock is preempt_disable(), and
> > might_sleep() already triggers if called inside preempt_disable().
> 
> It makes a difference if CONFIG_PREEMPT=n. AFAICS, preempt_disable()
> is a nop then and rcu needs its own check for sleeping while
> in read-side critical section.

Right.  I think enough people run with CONFIG_PREEMPT=y to make this
change rather unnecessary.

And if there are developers out there who are testing their code without an
effective CONFIG_DEBUG_SPINLOCK_SLEEP, then *that* is what we need to fix,
no?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-09-24 23:47    [from the cache]
©2003-2008