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Date: Tue, 8 Oct 2024 17:40:22 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Yunsheng Lin <linyunsheng@huawei.com>
Cc: <davem@davemloft.net>, <pabeni@redhat.com>, <liuyonglong@huawei.com>,
 <fanghaiqing@huawei.com>, <zhangkun09@huawei.com>, Alexander Lobakin
 <aleksander.lobakin@intel.com>, Jesper Dangaard Brouer <hawk@kernel.org>,
 Ilias Apalodimas <ilias.apalodimas@linaro.org>, Eric Dumazet
 <edumazet@google.com>, <netdev@vger.kernel.org>,
 <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net v2 1/2] page_pool: fix timing for checking and
 disabling napi_local
Message-ID: <20241008174022.0b6d92b9@kernel.org>
In-Reply-To: <20240925075707.3970187-2-linyunsheng@huawei.com>
References: <20240925075707.3970187-1-linyunsheng@huawei.com>
	<20240925075707.3970187-2-linyunsheng@huawei.com>
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On Wed, 25 Sep 2024 15:57:06 +0800 Yunsheng Lin wrote:
> Use rcu mechanism to avoid the above concurrent access problem.
> 
> Note, the above was found during code reviewing on how to fix
> the problem in [1].

The driver must make sure NAPI cannot be running while
page_pool_destroy() is called. There's even an WARN()
checking this.. if you know what to look for.