From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0627B27CCE0; Mon, 9 Mar 2026 12:52:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773060742; cv=none; b=M6kIqSFTHvxXzO6g7iFmMFq5wC3427dydMNe1EkNzWcp9XA/rQu0HCB7yEPtapK6XSgoiztOr6zjY+J86fF5NAPywJNqlyianfjSBbhsgJiDP+4hB9zF0bfCcI8/EHkj0fGvG5PF82vxtympZVI4ZcIvq01eg6LJPcuOV24SvC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773060742; c=relaxed/simple; bh=y/jG+6uQ1t0ozNKeVUtujZ0ZKaA2GN0iLu+iflTIVOA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=lEMbGy0V46WQYHZLuKG33Yp66YltdT7TK0yeCxYYihdOmwK5bjfibByGSykUguZBILs6CsdToLIBF6nz5CVojHgUjW4aQ3MrOqsBBs/xzgNDsvaEmHS2GZeFy4+OkVijW33rQLYqbpGmTrwemTZqRAOv44CuqX9k7iwQ0cJpS7c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ldURGgjZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ldURGgjZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF6D6C4CEF7; Mon, 9 Mar 2026 12:52:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773060741; bh=y/jG+6uQ1t0ozNKeVUtujZ0ZKaA2GN0iLu+iflTIVOA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ldURGgjZsupuiOEO8szY33Gv/w+ULtozZoSBSo5IQVXqhoQhUcsCx0Zgys2VjhVIf XnKGHJhLZPWQk2hRodapK9iZ9+DPqAAg0di8KkMwUHFnWOwwYk3LrPq3XWv4D60fSm lBg6JImoLkDIgNjxuRpw4o1D/geJl7QjJcuo5jLAfBr8zU2ewgEU9W7V0yDQLNLwgT gzl+2ZHX3B0pqhwOxlUt0ECHEBrtLS2ysXNPuXRjkNt6xAjHCcBqhSasV3YANLhMgG 5Ax23x/6raTJ/TFoxxfBwyEg6rBi70TldCa80OBwAp5X/nN7ymxdq8RVZfj+Ury4Lp kpMXnSdk5N14g== Message-ID: <9f5282ed-ddda-4d7c-b033-5b6d544d6cf4@kernel.org> Date: Mon, 9 Mar 2026 13:52:11 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH net 4/5] net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ: manual merge To: Tariq Toukan , Dragos Tatulea Cc: Saeed Mahameed , Leon Romanovsky , Mark Bloch , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Gal Pressman , Moshe Shemesh , Amery Hung , Nimrod Oren , Mark Brown , linux-next@vger.kernel.org, Eric Dumazet , Jakub Kicinski , Paolo Abeni , Andrew Lunn , "David S. Miller" References: <20260305142634.1813208-1-tariqt@nvidia.com> <20260305142634.1813208-5-tariqt@nvidia.com> From: Matthieu Baerts Content-Language: fr Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: <20260305142634.1813208-5-tariqt@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Tariq, Dragos, +cc: linux-next On 05/03/2026 15:26, Tariq Toukan wrote: > From: Dragos Tatulea > > XDP multi-buf programs can modify the layout of the XDP buffer when the > program calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The > referenced commit in the fixes tag corrected the assumption in the mlx5 > driver that the XDP buffer layout doesn't change during a program > execution. However, this fix introduced another issue: the dropped > fragments still need to be counted on the driver side to avoid page > fragment reference counting issues. FYI, we got a small conflict when merging 'net' in 'net-next' in the MPTCP tree due to this patch applied in 'net': db25c42c2e1f ("net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ") and this one from 'net-next': dff1c3164a69 ("net/mlx5e: SHAMPO, Always calculate page size") ----- Generic Message ----- The best is to avoid conflicts between 'net' and 'net-next' trees but if they cannot be avoided when preparing patches, a note about how to fix them is much appreciated. The conflict has been resolved on our side [1] and the resolution we suggest is attached to this email. Please report any issues linked to this conflict resolution as it might be used by others. If you worked on the mentioned patches, don't hesitate to ACK this conflict resolution. --------------------------- Rerere cache is available in [2]. [1] https://github.com/multipath-tcp/mptcp_net-next/commit/9cbb5f8a4a18 [2] https://github.com/multipath-tcp/mptcp-upstream-rr-cache/commit/0bbafdd (...) > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c > index efcfcddab376..40e53a612989 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c (...) > @@ -1975,13 +1974,12 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w > return NULL; /* page/packet was consumed by XDP */ > } > > - nr_frags_free = old_nr_frags - sinfo->nr_frags; > - if (unlikely(nr_frags_free)) { > - frag_page -= nr_frags_free; > + new_nr_frags = sinfo->nr_frags; > + nr_frags_free = old_nr_frags - new_nr_frags; > + if (unlikely(nr_frags_free)) > truesize -= (nr_frags_free - 1) * PAGE_SIZE + The conflict is in the context: this line above has been modified on 'net-next' (s/PAGE_SIZE/page_size/), while the ones above it have been modified on 'net'. Cheers, Matt -- Sponsored by the NGI0 Core fund. --- diff --cc drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index 8fb57a4f36dd,268e20884757..f5c0e2a0ada9 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@@ -1977,13 -1971,12 +1973,12 @@@ mlx5e_skb_from_cqe_mpwrq_nonlinear(stru return NULL; /* page/packet was consumed by XDP */ } - nr_frags_free = old_nr_frags - sinfo->nr_frags; - if (unlikely(nr_frags_free)) { - frag_page -= nr_frags_free; + new_nr_frags = sinfo->nr_frags; + nr_frags_free = old_nr_frags - new_nr_frags; + if (unlikely(nr_frags_free)) - truesize -= (nr_frags_free - 1) * PAGE_SIZE + + truesize -= (nr_frags_free - 1) * page_size + ALIGN(pg_consumed_bytes, BIT(rq->mpwqe.log_stride_sz)); - } len = mxbuf->xdp.data_end - mxbuf->xdp.data;