Re: [patch 021/104] lib/idr.c: fix rcu related race with idr_find

Dave Airlie
2008-12-10T00:43:20Z

On Wed, Dec 10, 2008 at 8:47 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
>
> On Wed, 10 Dec 2008, Dave Airlie wrote:
>>
>> On Thu, Dec 4, 2008 at 5:49 AM, Greg KH <gregkh@suse.de> wrote:
>> > 2.6.27-stable review patch. If anyone has any objections, please let us know.
>> >
>> Revert.
>>
>> This caused problems in the F10 kernel with idr, the drm device alloc
>> went all wierd,
>> it might be a drm bug but changing this code triggers it and so it
>> isn't really "stable"
>
> Well, maybe it should be reverted in mainlne too, then?

It appears idr_replace is broken at least in stable with this patch.

I'm trying to track down where the problem is (idr_replace doesn't look like
idr_find in a lot of places and I wonder if this has ever been tested.)

Dave.