Message-ID: <e5be0165-c398-c84b-4f16-18e5b302290d@intel.com>
Date:   Thu, 9 Mar 2023 17:25:40 +0100
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Subject: Re: [PATCH bpf-next v2 0/3] xdp: recycle Page Pool backed skbs built
 from XDP frames
To:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>
CC:     Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
        Larysa Zaremba <larysa.zaremba@intel.com>,
        =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= <toke@redhat.com>,
        Song Liu <song@kernel.org>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Menglong Dong <imagedong@tencent.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Eric Dumazet <edumazet@google.com>, <bpf@vger.kernel.org>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20230303133232.2546004-1-aleksander.lobakin@intel.com>
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From:   Alexander Lobakin <aleksander.lobakin@intel.com>
In-Reply-To: <20230303133232.2546004-1-aleksander.lobakin@intel.com>
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From: Alexander Lobakin <aleksander.lobakin@intel.com>
Date: Fri, 3 Mar 2023 14:32:29 +0100

> Yeah, I still remember that "Who needs cpumap nowadays" (c), but anyway.
> 
> __xdp_build_skb_from_frame() missed the moment when the networking stack
> became able to recycle skb pages backed by a page_pool. This was making
> e.g. cpumap redirect even less effective than simple %XDP_PASS. veth was
> also affected in some scenarios.
> A lot of drivers use skb_mark_for_recycle() already, it's been almost
> two years and seems like there are no issues in using it in the generic
> code too. {__,}xdp_release_frame() can be then removed as it losts its
> last user.
> Page Pool becomes then zero-alloc (or almost) in the abovementioned
> cases, too. Other memory type models (who needs them at this point)
> have no changes.

Ping?
The discussion in the v1 thread is unrelated to the patch subject :D

[...]

Thanks,
Olek