Re: [PATCH] slab: fix the DEADLOCK issue on l3 alien lock

Pekka Enberg
2012-09-08T08:39:19Z

On Fri, Sep 7, 2012 at 1:29 AM, Paul E. McKenney
<paulmck@linux.vnet.ibm.com> wrote:
> On Thu, Sep 06, 2012 at 11:05:11AM +0800, Michael Wang wrote:
>> On 09/05/2012 09:55 PM, Christoph Lameter wrote:
>> > On Wed, 5 Sep 2012, Michael Wang wrote:
>> >
>> >> Since the cachep and cachep->slabp_cache's l3 alien are in the same lock class,
>> >> fake report generated.
>> >
>> > Ahh... That is a key insight into why this occurs.
>> >
>> >> This should not happen since we already have init_lock_keys() which will
>> >> reassign the lock class for both l3 list and l3 alien.
>> >
>> > Right. I was wondering why we still get intermitted reports on this.
>> >
>> >> This patch will invoke init_lock_keys() after we done enable_cpucache()
>> >> instead of before to avoid the fake DEADLOCK report.
>> >
>> > Acked-by: Christoph Lameter <cl@linux.com>
>>
>> Thanks for your review.
>>
>> And add Paul to the cc list(my skills on mailing is really poor...).
>
> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

I'd also like to tag this for the stable tree to avoid bogus lockdep
reports. How far back in release history should we queue this?