On Tue, Sep 11, 2012 at 5:50 AM, Michael Wang <wangyun@xxxxxxxxxxxxxxxxxx> wrote: > On 09/08/2012 04:39 PM, Pekka Enberg wrote: >> On Fri, Sep 7, 2012 at 1:29 AM, Paul E. McKenney >> <paulmck@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxx> >>>> >>>> Thanks for your review. >>>> >>>> And add Paul to the cc list(my skills on mailing is really poor...). >>> >>> Tested-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> >> >> 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? > Hi, Pekka > > Sorry for the delayed reply, I try to find out the reason for commit > 30765b92 but not get it yet, so I add Peter to the cc list. > > The below patch for release 3.0.0 is the one to cause the bogus report. > > commit 30765b92ada267c5395fc788623cb15233276f5c > Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Date: Thu Jul 28 23:22:56 2011 +0200 > > slab, lockdep: Annotate the locks before using them > > Fernando found we hit the regular OFF_SLAB 'recursion' before we > annotate the locks, cure this. > > The relevant portion of the stack-trace: > > > [ 0.000000] [<c085e24f>] rt_spin_lock+0x50/0x56 > > [ 0.000000] [<c04fb406>] __cache_free+0x43/0xc3 > > [ 0.000000] [<c04fb23f>] kmem_cache_free+0x6c/0xdc > > [ 0.000000] [<c04fb2fe>] slab_destroy+0x4f/0x53 > > [ 0.000000] [<c04fb396>] free_block+0x94/0xc1 > > [ 0.000000] [<c04fc551>] do_tune_cpucache+0x10b/0x2bb > > [ 0.000000] [<c04fc8dc>] enable_cpucache+0x7b/0xa7 > > [ 0.000000] [<c0bd9d3c>] kmem_cache_init_late+0x1f/0x61 > > [ 0.000000] [<c0bba687>] start_kernel+0x24c/0x363 > > [ 0.000000] [<c0bba0ba>] i386_start_kernel+0xa9/0xaf > > Reported-by: Fernando Lopez-Lezcano <nando@xxxxxxxxxxxxxxxxxx> > Acked-by: Pekka Enberg <penberg@xxxxxxxxxx> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > Link: http://lkml.kernel.org/r/1311888176.2617.379.camel@laptop > Signed-off-by: Ingo Molnar <mingo@xxxxxxx> > > It moved init_lock_keys() before we build up the alien, so we failed to > reclass it. I've queued the patch for v3.7. Thanks! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>