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From:   Alexander Lobakin <alexandr.lobakin@intel.com>
To:     Shenwei Wang <shenwei.wang@nxp.com>
Cc:     Alexander Lobakin <alexandr.lobakin@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
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        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
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        Wei Fang <wei.fang@nxp.com>,
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        "imx@lists.linux.dev" <imx@lists.linux.dev>,
        kernel test robot <lkp@intel.com>
Subject: Re: [PATCH v3 1/1] net: fec: add xdp and page pool statistics
Date:   Mon, 14 Nov 2022 16:27:36 +0100
Message-Id: <20221114152736.702858-1-alexandr.lobakin@intel.com>
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From: Shenwei Wang <shenwei.wang@nxp.com>
Date: Mon, 14 Nov 2022 14:53:00 +0000

> > -----Original Message-----
> > From: Alexander Lobakin <alexandr.lobakin@intel.com>
> > Sent: Monday, November 14, 2022 7:46 AM
> > To: Shenwei Wang <shenwei.wang@nxp.com>
> > Cc: Alexander Lobakin <alexandr.lobakin@intel.com>; David S. Miller
> > <davem@davemloft.net>; Eric Dumazet <edumazet@google.com>; Jakub
> > Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; Alexei
> > Starovoitov <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>;
> >> @@ -29,6 +29,7 @@ config FEC
> >>       select CRC32
> >>       select PHYLIB
> >>       select PAGE_POOL
> >> +     select PAGE_POOL_STATS
> >
> > Drivers should never select PAGE_POOL_STATS. This Kconfig option was made to
> > allow user to choose whether he wants stats or better performance on slower
> > systems. It's pure user choice, if something doesn't build or link, it must be
> > guarded with IS_ENABLED(CONFIG_PAGE_POOL_STATS).
> 
> As the PAGE_POOL_STATS is becoming the infrastructure codes for many drivers, it is
> redundant for every driver to implement the stub function in case it is not selected. These
> stub functions should be provided by PAGE_POOL_STATS itself if the option is not selected.

Correct, but I think you added 'select PAGE_POOL_STATS' due to some
build issues on PPC64, or not? So if there are any when
!PAGE_POOL_STATS, it's always better to handle this at the Page Pool
API level in a separate patch.

> 
> >
> >>       imply NET_SELFTESTS
> >>       help
> >>         Say Y here if you want to use the built-in 10/100 Fast

Thanks,
Olek