From: Yibo Zhao <yiboz@codeaurora.org>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: ath10k@lists.infradead.org, linux-wireless@vger.kernel.org
Subject: Re: [PATCH V2 3/4] mac80211: fix low throughput in multi-clients situation
Date: Wed, 18 Sep 2019 18:29:37 +0800 [thread overview]
Message-ID: <38267df5b284bfd681ad69c7e816c5a4@codeaurora.org> (raw)
In-Reply-To: <874l19j56n.fsf@toke.dk>
On 2019-09-18 17:59, Toke Høiland-Jørgensen wrote:
> Yibo Zhao <yiboz@codeaurora.org> writes:
>
>> Not long after the start of multi-clients test, not a single station
>> is
>> an eligible candidate for transmission since global virtual time(g_vt)
>> is
>> smaller than the virtual airtime(s_vt) of all the stations. As a
>> result,
>> the Tx has been blocked and throughput is quite low.
>>
>> This may mainly due to sync mechanism and accumulative deviation from
>> the
>> devision calculation of g_vt.
>>
>> For example:
>> Suppose we have 50 clients in first round.
>> Round 1:
>> STA weight Tx_time_round wt_sum s_vt g_vt valid_for_next_Tx
>> . . . . .
>> . . . . .
>> . . . . .
>>
>> After this round, all the stations are not valid for next transmission
>> due
>> to accumulative deviation.
>>
>> And if we add a new #51,
>> Round 2:
>> STA weight Tx_time_round wt_sum s_vt g_vt valid_for_next_Tx
>> . . . . .
>> . . . . .
>> . . . . .
>>
>> Sync is done by:
>> max(g_vt of last round - grace period, s_vt)
>> and s_vt of #51 = max(2000 - 500, 0) + 1024 = 2524, and it is more
>> than the
>> final g_vt of this round.
>>
>> After this round, no more station is valid for transmission.
>
> I'm not sure I understand this. Was there supposed to be numbers in
> those tables above?
Yes, it looks like there are some display issues. Will fix it in next
version.
>
> -Toke
--
Yibo
next prev parent reply other threads:[~2019-09-18 10:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-18 9:47 [PATCH V2 1/4] mac80211: Switch to a virtual time-based airtime scheduler Yibo Zhao
2019-09-18 9:47 ` [PATCH V2 2/4] mac80211: defer txqs removal from rbtree Yibo Zhao
2019-09-18 9:47 ` [PATCH V2 3/4] mac80211: fix low throughput in multi-clients situation Yibo Zhao
2019-09-18 9:59 ` Toke Høiland-Jørgensen
2019-09-18 10:29 ` Yibo Zhao [this message]
2019-09-18 9:47 ` [PATCH V2 4/4] mac80211: Sync airtime weight sum with per AC synced sta airtime weight together Yibo Zhao
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