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Date: Tue, 8 Apr 2025 18:56:36 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-rt-devel@lists.linux.dev, netdev@vger.kernel.org, "David S.
 Miller" <davem@davemloft.net>, Andrew Lunn <andrew+netdev@lunn.ch>, Eric
 Dumazet <edumazet@google.com>, Ilias Apalodimas
 <ilias.apalodimas@linaro.org>, Jesper Dangaard Brouer <hawk@kernel.org>,
 Joe Damato <jdamato@fastly.com>, Paolo Abeni <pabeni@redhat.com>, Saeed
 Mahameed <saeedm@nvidia.com>, Simon Horman <horms@kernel.org>, Tariq Toukan
 <tariqt@nvidia.com>, Thomas Gleixner <tglx@linutronix.de>, Yunsheng Lin
 <linyunsheng@huawei.com>
Subject: Re: [PATCH net-next v3 0/4] page_pool: Convert stats to
 u64_stats_t.
Message-ID: <20250408185636.4adc61fb@kernel.org>
In-Reply-To: <20250408105922.1135150-1-bigeasy@linutronix.de>
References: <20250408105922.1135150-1-bigeasy@linutronix.de>
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On Tue,  8 Apr 2025 12:59:17 +0200 Sebastian Andrzej Siewior wrote:
> I don't know if it is ensured that only *one* update can happen because
> the stats are per-CPU and per NAPI device. But there will be now a
> warning on 32bit if this is really attempted in preemptible context.

I think recycling may happen in preemptible context, and from BH.
Have you tried to test?
The net.core.skb_defer_max sysctl may mask it for TCP traffic.