Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes: > On Tue, 2022-05-10 at 18:10 +0200, Felix Fietkau wrote: >> On 10.05.22 17:58, Alexander Wetzel wrote: >> > Let iTXQ drivers also register four queues in netdev and move queue >> > assignment to ndo_select_queue(), like it's done for other drivers. >> > >> > This gets rid of a special case in mac80211 and also increases the >> > chance that when we call skb_get_hash() the skb is still hot in the CPU >> > buffers. >> > >> > Signed-off-by: Alexander Wetzel <alexander@xxxxxxxxxxxxxx> >> >> This has the disadvantage of requiring a redundant sta lookup in the tx >> path for iTXQ drivers. I think the CPU cost of that one is probably >> higher than any potential gain from calling skb_get_hash a bit earlier. >> > > However, that's independent - we can still calculate the hash there, and > then bail out, i.e. put it right before the "if (wake_tx_queue) return" > part, no? > > OTOH we don't even need the hash in the other cases, do we? Nope, that was my point on the "moving it to shared netdev core" question :) -Toke
