From: Qian Cai <cai@lca.pw>
To: Waiman Long <longman@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
cgroups@vger.kernel.org, Juri Lelli <juri.lelli@redhat.com>
Subject: Re: [PATCH v2 4/4] mm/slub: Fix sysfs shrink circular locking dependency
Date: Mon, 27 Apr 2020 22:11:13 -0400 [thread overview]
Message-ID: <28BB8A1C-CFDF-4F5A-8686-537C3CE04818@lca.pw> (raw)
In-Reply-To: <dbbfe685-7374-9a96-b7c2-684142746e30@redhat.com>
> On Apr 27, 2020, at 9:39 PM, Waiman Long <longman@redhat.com> wrote:
>
> The sequence that was prevented by this patch is "kn->count --> mem_hotplug_lock.rwsem". This sequence isn't directly in the splat. Once this link is broken, the 3-lock circular loop cannot be formed. Maybe I should modify the commit log to make this point more clear.
I don’t know what you are talking about. Once trylock succeed once, you will have kn->count —> cpu/memory_hotplug_lock.
next prev parent reply other threads:[~2020-04-28 2:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-27 23:56 [PATCH v2 0/4] mm/slub: Fix sysfs " Waiman Long
2020-04-27 23:56 ` [PATCH v2 1/4] mm, slab: Revert "extend slab/shrink to shrink all memcg caches" Waiman Long
2020-04-27 23:56 ` [PATCH v2 2/4] mm/slub: Fix slab_mutex circular locking problem in slab_attr_store() Waiman Long
2020-04-27 23:56 ` [PATCH v2 3/4] mm/slub: Fix another circular locking dependency " Waiman Long
[not found] ` <F1FA6654-C07C-42FD-B497-61EB635B264C@lca.pw>
2020-05-18 22:05 ` Waiman Long
2020-04-27 23:56 ` [PATCH v2 4/4] mm/slub: Fix sysfs shrink circular locking dependency Waiman Long
2020-04-28 0:13 ` Qian Cai
2020-04-28 1:39 ` Waiman Long
2020-04-28 2:11 ` Qian Cai [this message]
2020-04-28 14:06 ` Waiman Long
2020-04-29 2:52 ` Qian Cai
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