From: Christopher Lameter <cl@linux.com>
To: Qian Cai <cai@lca.pw>
Cc: Daniel Wagner <dwagner@suse.de>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: lockdep warns: cpu_hotplug_lock.rw_sem --> slab_mutex --> kn->count#39
Date: Tue, 10 Dec 2019 18:32:37 +0000 (UTC) [thread overview]
Message-ID: <alpine.DEB.2.21.1912101829170.14347@www.lameter.com> (raw)
In-Reply-To: <2F924F88-8146-4868-9099-D824EAFA840E@lca.pw>
[-- Attachment #1: Type: text/plain, Size: 506 bytes --]
On Mon, 9 Dec 2019, Qian Cai wrote:
> It happens to me too with a probably easier to trigger deadlock. Basically, we have,
>
> memcg_create_kmem_cache():
> cpu_hotplug_lock.rw_sem/mem_hotplug_lock.rw_sem —> kn->count
Right. Memcg runs this function at cgroup creation time. sysfs
initialization was designed to run a at boot. So the sysfs initialization
needs a rewrite of its serialization for the memcg case. We cannot loop
over the list of all kmem caches holding the slab_mutex anymore.
prev parent reply other threads:[~2019-12-10 18:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 18:24 Daniel Wagner
2019-12-09 20:33 ` Christopher Lameter
2019-12-09 20:46 ` Daniel Wagner
2019-12-10 3:21 ` Qian Cai
2019-12-10 3:34 ` Qian Cai
2019-12-10 18:32 ` Christopher Lameter [this message]
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