On 2016-09-08 13:41, Kalle Valo wrote: > Zefir Kurtisi <zefir.kurtisi@xxxxxxxxxxx> writes: > >> On 08/11/2016 09:27 PM, Felix Fietkau wrote: >>> On 2016-08-11 18:05, Zefir Kurtisi wrote: >>>> On 08/04/2016 11:49 PM, Felix Fietkau wrote: >>>>> It removes the need for undoing the padding changes to skb->data and it >>>>> improves performance by eliminating one tx status lookup per MPDU in the >>>>> status path. It is also useful for preparing a follow-up fix to better >>>>> handle powersave filtering. >>>>> >>>> >>>> For me, this one introduces a regression to the statistics, e.g. >>>> 'dot11TransmittedFragmentCount' is now accounted differently since it is not >>>> updated from within ieee80211_tx_status_noskb(). >>> Is this important? I guess it would be possible to make this more >>> accurate by extending the API, but I wonder if that's worth doing just >>> for these debugfs counters. >>> >> If you want to support the IEEE802dot11.MIB (dot11mac.dot11CountersTable), they >> are important. Not sure though if it is used by others besides us. >> >> I think the real issue here is that those counters are regarded as internal debug >> values (as the comments or e.g. commit c206ca6709 state) instead of general >> purpose statistics that is exposed to SNMP. As such, they should be configurable >> as a feature independent of debug settings in mac80211. >> >> >> Aside from that consideration, this patch (with the follow up ones) increased peak >> performance noticeably (we measure some 5%+ higher peak throughput), which for >> sure is worth dropping the counters for most. >> >> I am fine handling this internally. A note in the commit message would be helpful >> that states that counters dot11TransmittedFragmentCount, dot11FrameDuplicateCount, >> dot11ReceivedFragmentCount, and dot11MulticastReceivedFrameCount become invalid. > > A good idea, I updated the commit log to mention that. Does that look > ok? > > Author: Felix Fietkau <nbd@xxxxxxxx> > Date: Fri Sep 2 19:46:12 2016 +0300 > > ath9k: use ieee80211_tx_status_noskb where possible > > It removes the need for undoing the padding changes to skb->data and it > improves performance by eliminating one tx status lookup per MPDU in the > status path. It is also useful for preparing a follow-up fix to better > handle powersave filtering. > > A side effect is that these counters, available via debugfs, become now invalid: > > * dot11TransmittedFragmentCount > * dot11FrameDuplicateCount, > * dot11ReceivedFragmentCount > * dot11MulticastReceivedFrameCount > > Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Looks good to me. - Felix
