From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Johannes Berg <johannes@sipsolutions.net>,
Arend Van Spriel <arend.vanspriel@broadcom.com>,
Felix Fietkau <nbd@nbd.name>,
linux-wireless@vger.kernel.org,
Eric Dumazet <eric.dumazet@gmail.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH 5/5] mac80211: set NETIF_F_LLTX when using intermediate tx queues
Date: Wed, 17 Apr 2019 09:28:51 +0100 [thread overview]
Message-ID: <875zrdt4qk.fsf@toke.dk> (raw)
In-Reply-To: <20190417021101.5a32gox2ivbcgsbp@gondor.apana.org.au>
Herbert Xu <herbert@gondor.apana.org.au> writes:
> On Tue, Apr 16, 2019 at 11:02:50AM +0100, Toke Høiland-Jørgensen wrote:
>>
>> As explained at great length here:
>> https://www.usenix.org/conference/atc17/technical-sessions/presentation/hoilan-jorgesen
>> (you already know that of course, Johannes)
>
> I can understand that wireless needs its own queueing scheme, but it
> still seems wrong to place that under net/mac80211 as opposed to
> having it as a first-class citizen under net/sched.
This is because we need to resolve the MAC-layer destination station (or
rather, TID) and tie the queueing to that, because of aggregation. We
also use the queueing structure for scheduling stations to achieve
airtime fairness. Both of these would be decidedly non-trivial to pull
up to the qdisc layer. Rather, having them in mac80211 means drivers
don't need to do their own ad-hoc queueing (which was the case before,
leading extra bufferbloat).
Most of the actual queueing structure code lives in
include/net/fq_impl.h, though, so it's not actually that
mac80211-specific. I've been thinking about porting the relevant qdiscs
to use the same code, but I'm not sure that it's worth the trouble.
-Toke
next prev parent reply other threads:[~2019-04-17 8:36 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-16 17:06 [PATCH 1/5] mac80211: mesh: drop redundant rcu_read_lock/unlock calls Felix Fietkau
2019-03-16 17:06 ` [PATCH 2/5] mac80211: fix memory accounting with A-MSDU aggregation Felix Fietkau
2019-03-16 18:12 ` Toke Høiland-Jørgensen
2019-03-16 17:06 ` [PATCH 3/5] mac80211: calculate hash for fq without holding fq->lock in itxq enqueue Felix Fietkau
2019-03-16 18:13 ` Toke Høiland-Jørgensen
2019-03-16 17:06 ` [PATCH 4/5] mac80211: run late dequeue late tx handlers without holding fq->lock Felix Fietkau
2019-03-16 18:13 ` Toke Høiland-Jørgensen
2022-12-05 9:46 ` Wen Gong
2022-12-07 6:30 ` Wen Gong
2022-12-12 8:31 ` Wen Gong
2019-03-16 17:06 ` [PATCH 5/5] mac80211: set NETIF_F_LLTX when using intermediate tx queues Felix Fietkau
2019-03-16 18:14 ` Toke Høiland-Jørgensen
2019-04-14 9:44 ` Arend Van Spriel
2019-04-14 11:19 ` Felix Fietkau
2019-04-14 12:34 ` Arend Van Spriel
2019-04-16 7:34 ` Arend Van Spriel
2019-04-16 7:44 ` Herbert Xu
2019-04-16 8:04 ` Arend Van Spriel
2019-04-16 8:36 ` Herbert Xu
2019-04-16 8:37 ` Johannes Berg
2019-04-16 9:17 ` Arend Van Spriel
2019-04-16 9:29 ` Herbert Xu
2019-04-16 9:33 ` Toke Høiland-Jørgensen
2019-04-16 9:33 ` Johannes Berg
2019-04-16 9:37 ` Herbert Xu
2019-04-16 9:39 ` Johannes Berg
2019-04-16 10:02 ` Toke Høiland-Jørgensen
2019-04-17 2:11 ` Herbert Xu
2019-04-17 8:28 ` Toke Høiland-Jørgensen [this message]
2019-04-16 13:13 ` Herbert Xu
2019-04-16 13:18 ` Toke Høiland-Jørgensen
2019-04-17 3:38 ` Herbert Xu
2019-04-17 9:09 ` Toke Høiland-Jørgensen
2019-04-17 9:16 ` Arend Van Spriel
2019-04-17 9:17 ` Toke Høiland-Jørgensen
2019-04-23 12:41 ` Johannes Berg
2019-04-25 8:35 ` Herbert Xu
2019-04-25 8:39 ` Johannes Berg
2019-04-25 8:44 ` Herbert Xu
2019-04-25 8:49 ` Johannes Berg
2019-04-16 19:13 ` Johannes Berg
2019-04-17 2:13 ` Herbert Xu
2019-04-16 9:38 ` Toke Høiland-Jørgensen
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