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Date:   Tue, 15 Nov 2022 18:12:02 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     Shenwei Wang <shenwei.wang@nxp.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        John Fastabend <john.fastabend@gmail.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        imx@lists.linux.dev
Subject: Re: [PATCH v4 1/2] net: page_pool: export page_pool_stats definition
Message-ID: <Y3PIYg+VsuBxq5cW@lunn.ch>
References: <20221115155744.193789-1-shenwei.wang@nxp.com>
 <20221115155744.193789-2-shenwei.wang@nxp.com>
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On Tue, Nov 15, 2022 at 09:57:43AM -0600, Shenwei Wang wrote:
> The definition of the 'struct page_pool_stats' is required even when
> the CONFIG_PAGE_POOL_STATS is not defined. Otherwise, it is required
> the drivers to handle the case of CONFIG_PAGE_POOL_STATS undefined.

I agree the API is broken, but i think there is a better fix.

There should be a stub of page_pool_get_stats() for when
CONFIG_PAGE_POOL_STATS is disabled.

Nothing actually dereferences struct page_pool_stats when you have
this stub. So it might be enough to simply have

struct page_pool_stats{
};

       Andrew