From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
Linux MM <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-renesas-soc@vger.kernel.org,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: Boot failure on emev2/kzm9d (was: Re: [PATCH v2 11/11] mm/slab: lockless decision to grow cache)
Date: Tue, 28 Jun 2016 17:33:57 +0900 [thread overview]
Message-ID: <20160628083357.GE19731@js1304-P5Q-DELUXE> (raw)
In-Reply-To: <20160628001243.GA20638@linux.vnet.ibm.com>
On Mon, Jun 27, 2016 at 05:12:43PM -0700, Paul E. McKenney wrote:
> On Wed, Jun 22, 2016 at 07:53:29PM -0700, Paul E. McKenney wrote:
> > On Wed, Jun 22, 2016 at 07:47:42PM -0700, Paul E. McKenney wrote:
> > > On Thu, Jun 23, 2016 at 11:37:56AM +0900, Joonsoo Kim wrote:
> > > > On Wed, Jun 22, 2016 at 05:49:35PM -0700, Paul E. McKenney wrote:
> > > > > On Wed, Jun 22, 2016 at 12:08:59PM -0700, Paul E. McKenney wrote:
> > > > > > On Wed, Jun 22, 2016 at 05:01:35PM +0200, Geert Uytterhoeven wrote:
> > > > > > > On Wed, Jun 22, 2016 at 2:52 AM, Joonsoo Kim <iamjoonsoo.kim@lge.com> wrote:
> > > > > > > > Could you try below patch to check who causes the hang?
> > > > > > > >
> > > > > > > > And, if sysalt-t works when hang, could you get sysalt-t output? I haven't
> > > > > > > > used it before but Paul could find some culprit on it. :)
> > > > > > > >
> > > > > > > > Thanks.
> > > > > > > >
> > > > > > > >
> > > > > > > > ----->8-----
> > > > > > > > diff --git a/mm/slab.c b/mm/slab.c
> > > > > > > > index 763096a..9652d38 100644
> > > > > > > > --- a/mm/slab.c
> > > > > > > > +++ b/mm/slab.c
> > > > > > > > @@ -964,8 +964,13 @@ static int setup_kmem_cache_node(struct kmem_cache *cachep,
> > > > > > > > * guaranteed to be valid until irq is re-enabled, because it will be
> > > > > > > > * freed after synchronize_sched().
> > > > > > > > */
> > > > > > > > - if (force_change)
> > > > > > > > + if (force_change) {
> > > > > > > > + if (num_online_cpus() > 1)
> > > > > > > > + dump_stack();
> > > > > > > > synchronize_sched();
> > > > > > > > + if (num_online_cpus() > 1)
> > > > > > > > + dump_stack();
> > > > > > > > + }
> > > > > > >
> > > > > > > I've only added the first one, as I would never see the second one. All of
> > > > > > > this happens before the serial console is activated, earlycon is not supported,
> > > > > > > and I only have remote access.
> > > > > > >
> > > > > > > Brought up 2 CPUs
> > > > > > > SMP: Total of 2 processors activated (2132.00 BogoMIPS).
> > > > > > > CPU: All CPU(s) started in SVC mode.
> > > > > > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> > > > > > > 4.7.0-rc4-kzm9d-00404-g4a235e6dde4404dd-dirty #89
> > > > > > > Hardware name: Generic Emma Mobile EV2 (Flattened Device Tree)
> > > > > > > [<c010de68>] (unwind_backtrace) from [<c010a658>] (show_stack+0x10/0x14)
> > > > > > > [<c010a658>] (show_stack) from [<c02b5cf8>] (dump_stack+0x7c/0x9c)
> > > > > > > [<c02b5cf8>] (dump_stack) from [<c01cfa4c>] (setup_kmem_cache_node+0x140/0x170)
> > > > > > > [<c01cfa4c>] (setup_kmem_cache_node) from [<c01cfe3c>]
> > > > > > > (__do_tune_cpucache+0xf4/0x114)
> > > > > > > [<c01cfe3c>] (__do_tune_cpucache) from [<c01cff54>] (enable_cpucache+0xf8/0x148)
> > > > > > > [<c01cff54>] (enable_cpucache) from [<c01d0190>]
> > > > > > > (__kmem_cache_create+0x1a8/0x1d0)
> > > > > > > [<c01d0190>] (__kmem_cache_create) from [<c01b32d0>]
> > > > > > > (kmem_cache_create+0xbc/0x190)
> > > > > > > [<c01b32d0>] (kmem_cache_create) from [<c070d968>] (shmem_init+0x34/0xb0)
> > > > > > > [<c070d968>] (shmem_init) from [<c0700cc8>] (kernel_init_freeable+0x98/0x1ec)
> > > > > > > [<c0700cc8>] (kernel_init_freeable) from [<c049fdbc>] (kernel_init+0x8/0x110)
> > > > > > > [<c049fdbc>] (kernel_init) from [<c0106cb8>] (ret_from_fork+0x14/0x3c)
> > > > > > > devtmpfs: initialized
> > > > > >
> > > > > > I don't see anything here that would prevent grace periods from completing.
> > > > > >
> > > > > > The CPUs are using the normal hotplug sequence to come online, correct?
> > > > >
> > > > > And either way, could you please apply the patch below and then
> > > > > invoke rcu_dump_rcu_sched_tree() just before the offending call to
> > > > > synchronize_sched()? That will tell me what CPUs RCU believes exist,
> > > > > and perhaps also which CPU is holding it up.
> > > >
> > > > I can't find rcu_dump_rcu_sched_tree(). Do you mean
> > > > rcu_dump_rcu_node_tree()? Anyway, there is no patch below so I attach
> > > > one which does what Paul want, maybe.
> > >
> > > One of those days, I guess! :-/
> > >
> > > Your patch is exactly what I intended to send, thank you!
> >
> > Ah, but your telepathy was not sufficient to intuit the additional
> > information I need. Please see the patch at the end. Your hunk
> > in mm/slab.c is needed on top of my patch.
> >
> > So I am clearly having difficulties reading as well as including patches
> > today...
>
> Just following up, any news using my diagnostic patch?
Hello, Paul.
Unfortunately, I have no hardware to re-generate it, so we need to wait Geert's
feedback.
Thanks.
next prev parent reply other threads:[~2016-06-28 8:31 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-13 19:43 Boot failure on emev2/kzm9d (was: Re: [PATCH v2 11/11] mm/slab: lockless decision to grow cache) Geert Uytterhoeven
2016-06-14 6:24 ` Joonsoo Kim
2016-06-14 7:31 ` Geert Uytterhoeven
2016-06-14 8:11 ` Joonsoo Kim
2016-06-14 10:45 ` Geert Uytterhoeven
2016-06-15 2:23 ` Joonsoo Kim
2016-06-15 8:39 ` Geert Uytterhoeven
2016-06-20 6:39 ` Joonsoo Kim
2016-06-20 13:12 ` Paul E. McKenney
2016-06-21 6:43 ` Joonsoo Kim
2016-06-21 12:54 ` Paul E. McKenney
2016-06-22 0:52 ` Joonsoo Kim
2016-06-22 3:15 ` Paul E. McKenney
2016-06-22 15:01 ` Geert Uytterhoeven
2016-06-22 19:08 ` Paul E. McKenney
2016-06-23 0:49 ` Paul E. McKenney
2016-06-23 2:37 ` Joonsoo Kim
2016-06-23 2:47 ` Paul E. McKenney
2016-06-23 2:53 ` Paul E. McKenney
2016-06-28 0:12 ` Paul E. McKenney
2016-06-28 8:33 ` Joonsoo Kim [this message]
2016-06-29 14:54 ` Geert Uytterhoeven
2016-06-29 16:44 ` Paul E. McKenney
2016-06-29 17:52 ` Geert Uytterhoeven
2016-06-29 18:12 ` Paul E. McKenney
2016-06-30 7:47 ` Joonsoo Kim
2016-06-30 7:58 ` Geert Uytterhoeven
2016-06-30 13:24 ` Paul E. McKenney
2016-06-30 13:31 ` Geert Uytterhoeven
2016-06-30 15:18 ` Paul E. McKenney
2016-06-30 15:53 ` Geert Uytterhoeven
2016-06-30 16:52 ` Paul E. McKenney
2016-06-30 17:54 ` Geert Uytterhoeven
2016-06-14 13:10 ` Geert Uytterhoeven
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