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From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Yibo Zhao <yiboz@codeaurora.org>
Cc: linux-wireless-owner@vger.kernel.org,
	linux-wireless@vger.kernel.org, ath10k@lists.infradead.org
Subject: Re: [PATCH V3 3/4] mac80211: fix low throughput in multi-clients situation
Date: Tue, 24 Sep 2019 10:48:53 +0200	[thread overview]
Message-ID: <87d0fq3wqy.fsf@toke.dk> (raw)
In-Reply-To: <2aab0bd944ee34751304a5f92b885113@codeaurora.org>

Yibo Zhao <yiboz@codeaurora.org> writes:

>> I can see why we need the second part (basically, this happens because 
>> I
>> forgot to add a check for "no eligible stations" in may_transmit(), 
>> like
>> the one in next_txq()). And rounding up the division result doesn't
>> hurt, I guess. But why does it help to change the grace period if we're
>> doing all the other stuff?
> In multi-clients case, it is possible a TXQ sometimes gets drained due 
> to FW has deep queue and few packets in TXQ at that time. So the TXQ is 
> removed from the rbtree after dequeuing. When it is about to added back 
> very soon after the removal, the g_vt might have gone a little far away 
> from sta vt where sync is needed. With this sync, the station is forced 
> to catch up with the g_vt, however, its chance for transmission has been 
> reduced. I think 500us is quite a short period in multi-clients case.

That's a good point, actually: Having the grace period be too small will
allow stations that leave and re-enter the queue to "skip ahead" and use
more than its share. However, I think it's a separate issue from what
this patch is about; so how about I just increase the grace period in
the next version of the base patch?

-Toke


_______________________________________________
ath10k mailing list
ath10k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath10k

WARNING: multiple messages have this Message-ID (diff)
From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Yibo Zhao <yiboz@codeaurora.org>
Cc: linux-wireless@vger.kernel.org, ath10k@lists.infradead.org,
	linux-wireless-owner@vger.kernel.org
Subject: Re: [PATCH V3 3/4] mac80211: fix low throughput in multi-clients situation
Date: Tue, 24 Sep 2019 10:48:53 +0200	[thread overview]
Message-ID: <87d0fq3wqy.fsf@toke.dk> (raw)
In-Reply-To: <2aab0bd944ee34751304a5f92b885113@codeaurora.org>

Yibo Zhao <yiboz@codeaurora.org> writes:

>> I can see why we need the second part (basically, this happens because 
>> I
>> forgot to add a check for "no eligible stations" in may_transmit(), 
>> like
>> the one in next_txq()). And rounding up the division result doesn't
>> hurt, I guess. But why does it help to change the grace period if we're
>> doing all the other stuff?
> In multi-clients case, it is possible a TXQ sometimes gets drained due 
> to FW has deep queue and few packets in TXQ at that time. So the TXQ is 
> removed from the rbtree after dequeuing. When it is about to added back 
> very soon after the removal, the g_vt might have gone a little far away 
> from sta vt where sync is needed. With this sync, the station is forced 
> to catch up with the g_vt, however, its chance for transmission has been 
> reduced. I think 500us is quite a short period in multi-clients case.

That's a good point, actually: Having the grace period be too small will
allow stations that leave and re-enter the queue to "skip ahead" and use
more than its share. However, I think it's a separate issue from what
this patch is about; so how about I just increase the grace period in
the next version of the base patch?

-Toke


  reply	other threads:[~2019-09-24  8:49 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-23  7:19 [PATCH V3 0/4] Enable virtual time-based airtime scheduler support on ath10k Yibo Zhao
2019-09-23  7:19 ` Yibo Zhao
2019-09-23  7:19 ` [PATCH V3 1/4] mac80211: Switch to a virtual time-based airtime scheduler Yibo Zhao
2019-09-23  7:19   ` Yibo Zhao
2019-09-23  7:19 ` [PATCH V3 2/4] mac80211: defer txqs removal from rbtree Yibo Zhao
2019-09-23  7:19   ` Yibo Zhao
2019-09-23 10:56   ` Toke Høiland-Jørgensen
2019-09-23 10:56     ` Toke Høiland-Jørgensen
2019-09-24  2:55     ` Yibo Zhao
2019-09-24  2:55       ` Yibo Zhao
2019-09-23  7:20 ` [PATCH V3 3/4] mac80211: fix low throughput in multi-clients situation Yibo Zhao
2019-09-23  7:20   ` Yibo Zhao
2019-09-23 10:55   ` Toke Høiland-Jørgensen
2019-09-23 10:55     ` Toke Høiland-Jørgensen
2019-09-24  8:22     ` Yibo Zhao
2019-09-24  8:22       ` Yibo Zhao
2019-09-24  8:48       ` Toke Høiland-Jørgensen [this message]
2019-09-24  8:48         ` Toke Høiland-Jørgensen
2019-09-24  8:58         ` Yibo Zhao
2019-09-24  8:58           ` Yibo Zhao
2019-09-23  7:20 ` [PATCH V3 4/4] mac80211: Sync airtime weight sum with per AC synced sta airtime weight together Yibo Zhao
2019-09-23  7:20   ` Yibo Zhao
2019-09-23 11:00   ` Toke Høiland-Jørgensen
2019-09-23 11:00     ` Toke Høiland-Jørgensen
2019-09-24  3:19     ` Yibo Zhao
2019-09-24  3:19       ` Yibo Zhao
2019-09-24  7:27       ` Toke Høiland-Jørgensen
2019-09-24  7:27         ` Toke Høiland-Jørgensen
2019-10-01 10:19 ` [PATCH V3 0/4] Enable virtual time-based airtime scheduler support on ath10k Johannes Berg
2019-10-01 10:19   ` Johannes Berg
2019-10-01 10:59   ` Yibo Zhao
2019-10-01 10:59     ` Yibo Zhao
2019-10-01 11:05     ` Toke Høiland-Jørgensen
2019-10-01 11:05       ` Toke Høiland-Jørgensen

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