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I don't > have much of an opinion on that front. But if you do want to introduce > a new tx_extra_headroom, could we try really hard to have it auto- > tuning? For TC-BPF I suppose only the BPF program knows how much extra headroom is needed. Maybe this tx_extra_headroom could be declared as a BTF decl tag in the program. If this is the only usecase there's no need for a rtnetlink uAPI. Thanks, Dragos