Re: [PATCH RFC v3 2/4] mac80211: Add airtime accounting and scheduling to TXQs
From: Rajkumar Manoharan <hidden>
Date: 2018-09-12 21:29:06
On 2018-09-12 04:10, Toke Høiland-Jørgensen wrote:
Rajkumar Manoharan [off-list ref] writes:quoted
On 2018-09-10 04:13, Toke Høiland-Jørgensen wrote:quoted
Johannes Berg [off-list ref] writes:quoted
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- txqi->flags & (1<<IEEE80211_TXQ_STOP) ? "STOP" : "RUN", - txqi->flags & (1<<IEEE80211_TXQ_AMPDU) ? " AMPDU" : "", - txqi->flags & (1<<IEEE80211_TXQ_NO_AMSDU) ? " NO-AMSDU" : ""); + txqi->flags & (1 << IEEE80211_TXQ_STOP) ? "STOP" : "RUN", + txqi->flags & (1 << IEEE80211_TXQ_AMPDU) ? " AMPDU" : "", + txqi->flags & (1 << IEEE80211_TXQ_NO_AMSDU) ? " NO-AMSDU" : "");consider BIT() instead as a cleanup? :) (or maybe this is just a leftover from merging some other patches?)Yeah, this is a merging artifact; Rajkumar's patch added another flag, that I removed again. Didn't notice that there was still a whitespace change in this patch...I added the flag based on our last discussion. The driver needs to check txq status for each tx_dequeue(). One time txq check is not sufficient as it allows the driver to dequeue all frames from txq. drv_func() { while (ieee80211_airtime_may_transmit(txq) && hw_has_space() && (pkt = ieee80211_tx_dequeue(hw, txq))) push_to_hw(pkt); }Yeah, but with airtime only being recorded on TX completion, the odds of the value changing within that loop are quite low; so it's not going to work, which is why I removed it. However, after reading Kan's patches I get where you're coming from; a check in tx_dequeue() is needed for the BQL-style queue limiting. Will try to incorporate a version of that in the next series so you can see what I mean when I say it should be orthogonal; and I'm still not sure it needs a flag :)
Got it.. Will wait for next version.. thanks.
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+bool ieee80211_txq_may_transmit(struct ieee80211_hw *hw, + struct ieee80211_txq *txq) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct txq_info *txqi = to_txq_info(txq); + bool may_tx = false; + + spin_lock_bh(&local->active_txq_lock); + + if (ieee80211_txq_check_deficit(local, txqi)) { + may_tx = true; + list_del_init(&txqi->schedule_order);To handle above case, may_transmit should remove the node only when it is in list. if (list_empty(&txqi->schedule_order)) list_del_init(&txqi->schedule_order);I assume you missed a ! in that if, right? :)
Oops.. yes it should be ! :) -Rajkumar