From: Andrew Morton <akpm@linux-foundation.org>
To: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org, Zqiang <qiang.zhang1211@gmail.com>,
Zhen Lei <thunder.leizhen@huaweicloud.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
rcu@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 2/2] rcu: Dump vmalloc memory info safely
Date: Sat, 2 Sep 2023 18:28:28 -0700 [thread overview]
Message-ID: <20230902182828.e42c6ec7b4a7beb1e4b2b042@linux-foundation.org> (raw)
In-Reply-To: <20230830110402.386898-2-joel@joelfernandes.org>
On Wed, 30 Aug 2023 11:04:00 +0000 "Joel Fernandes (Google)" <joel@joelfernandes.org> wrote:
> Currently, for double invoke call_rcu(), will dump rcu_head objects
> memory info, if the objects is not allocated from the slab allocator,
> the vmalloc_dump_obj() will be invoke and the vmap_area_lock spinlock
> need to be held, since the call_rcu() can be invoked in interrupt context,
> therefore, there is a possibility of spinlock deadlock scenarios.
>
> And in Preempt-RT kernel, the rcutorture test also trigger the following
> lockdep warning:
"possibility of deadlock" sounds like something -stable kernels would
like to have fixed.
Did you consider the desirability of a -stable backport?
If so, are we able to identify a suitable Fixes: target?
next prev parent reply other threads:[~2023-09-03 1:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-30 11:03 [PATCH 1/2] mm/vmalloc: Add a safer version of find_vm_area() for debug Joel Fernandes (Google)
2023-08-30 11:04 ` [PATCH 2/2] rcu: Dump vmalloc memory info safely Joel Fernandes (Google)
2023-08-30 12:08 ` Matthew Wilcox
2023-09-03 1:28 ` Andrew Morton [this message]
2023-09-03 2:03 ` Joel Fernandes
2023-09-03 2:05 ` Joel Fernandes
2023-08-30 12:07 ` [PATCH 1/2] mm/vmalloc: Add a safer version of find_vm_area() for debug Matthew Wilcox
2023-08-30 12:17 ` Joel Fernandes
2023-08-30 12:48 ` Christoph Hellwig
2023-08-30 13:09 ` Joel Fernandes
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