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Date: Wed, 4 Mar 2026 18:55:31 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Larysa Zaremba <larysa.zaremba@intel.com>
Cc: bpf@vger.kernel.org, Claudiu Manoil <claudiu.manoil@nxp.com>, Vladimir
 Oltean <vladimir.oltean@nxp.com>, Wei Fang <wei.fang@nxp.com>, Clark Wang
 <xiaoning.wang@nxp.com>, Andrew Lunn <andrew+netdev@lunn.ch>, "David S.
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 Aleksandr Loktionov <aleksandr.loktionov@intel.com>, Dragos Tatulea
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Subject: Re: [PATCH bpf v4 0/9] Address XDP frags having negative tailroom
Message-ID: <20260304185531.4f49fda4@kernel.org>
In-Reply-To: <20260302161723.858616-1-larysa.zaremba@intel.com>
References: <20260302161723.858616-1-larysa.zaremba@intel.com>
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On Mon,  2 Mar 2026 17:17:13 +0100 Larysa Zaremba wrote:
> Aside from the issue described below, tailroom calculation does not account
> for pages being split between frags, e.g. in i40e, enetc and
> AF_XDP ZC with smaller chunks. These series address the problem by
> calculating modulo (skb_frag_off() % rxq->frag_size) in order to get
> data offset within a smaller block of memory. Please note, xskxceiver
> tail grow test passes without modulo e.g. in xdpdrv mode on i40e,
> because there is not enough descriptors to get to flipped buffers.

This was re-assigned to netdev in pw, I presume by BPF maintainers.
But it doesn't apply to net. There's a conflict in ice.
Could you rebase on net and repost?