Re: [PATCH v4] ath9k: Switch to using mac80211 intermediate software queues.

Toke Høiland-Jørgensen [off-list ref] writes:

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This is great work but due to the regressions I'm not sure if this
will be ready for 4.9. To get more testing time I wonder if we should
wait for 4.10? IMHO applying this in the end of the cycle is too risky
and we should try to maximise the time linux-next by applying this
just after -rc1 is released.

Thoughts?

Well, now that we understand what is causing the throughput regressions,
fixing them should be fairly straight forward (yeah, famous last words,
but still...). I already have a patch for the fast path and will go poke
at the slow path next. It'll probably require another workaround or two,
so I guess it won't be the architecturally clean ideal solution; but it
would make it possible to have something that works for 4.9 and then
iterate for a cleaner design for 4.10.

But if we try to rush this to 4.9 it won't be in linux-next for long. We
are now in -rc3 and let's say that the patches are ready to apply in two
weeks. That would leave us only two weeks of -next time before the merge
window, which I think is not enough for a controversial patch like this
one. There might be other bugs lurking which haven't been found yet.

What, other hidden bugs? Unpossible! :)

Yeah, right ;)

Would it be possible to merge the partial solution (which is ready now,
basically) and fix the slow path in a separate patch later?

What do you mean with partial solution? You mean ath9k users would
suffer from regressions until they are fixed? We can't do that.

(Just spit-balling here; I'm still fairly new to this process. But I am
concerned that we'll hit a catch-22 where we can't get wider testing
before it's "ready" and we can't prove that it's "ready" until we've had
wider testing...)

I understand your point, but I don't want to rush this to 4.9 and then
start getting lots of bug reports and eventually forced to revert it. If
we just found a new serious regression the chances are that there are
more lurking somewhere and this patch is just not ready yet.

-- 
Kalle Valo