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Date: Fri, 26 Apr 2024 16:08:59 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Mina Almasry <almasrymina@google.com>
Cc: Dragos Tatulea <dtatulea@nvidia.com>, "davem@davemloft.net"
 <davem@davemloft.net>, "pabeni@redhat.com" <pabeni@redhat.com>,
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 "netdev@vger.kernel.org" <netdev@vger.kernel.org>, Jianbo Liu
 <jianbol@nvidia.com>, "edumazet@google.com" <edumazet@google.com>
Subject: Re: [RFC PATCH] net: Fix one page_pool page leak from
 skb_frag_unref
Message-ID: <20240426160859.0d85908e@kernel.org>
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On Thu, 25 Apr 2024 12:20:59 -0700 Mina Almasry wrote:
> -       if (recycle && napi_pp_get_page(page))
> +       if (napi_pp_get_page(page))

Pretty sure you can't do that. The "recycle" here is a concurrency
guarantee. A guarantee someone is holding a pp ref on that page,
a ref which will not go away while napi_pp_get_page() is executing.