From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nbd.name (nbd.name [IPv6:2a01:4f8:131:30e2::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 6B3123B2A0 for ; Fri, 17 Jun 2016 09:48:16 -0400 (EDT) To: =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= References: <20160617090929.31606-1-toke@toke.dk> <20160617090929.31606-2-toke@toke.dk> <30beabff-a8c6-5431-be09-8f2f83ffc974@nbd.name> <87d1ng3p8g.fsf@toke.dk> Cc: linux-wireless@vger.kernel.org, make-wifi-fast@lists.bufferbloat.net, ath9k-devel@lists.ath9k.org, Tim Shepard From: Felix Fietkau Message-ID: <372794e9-327a-1ff9-9888-f9826c787801@nbd.name> User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <87d1ng3p8g.fsf@toke.dk> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Mon, 28 Nov 2016 08:47:10 -0500 Subject: Re: [Make-wifi-fast] [PATCH 1/2] ath9k: use mac80211 intermediate software queues X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Date: Fri, 17 Jun 2016 13:48:16 -0000 X-Original-Date: Fri, 17 Jun 2016 15:48:13 +0200 X-List-Received-Date: Fri, 17 Jun 2016 13:48:16 -0000 On 2016-06-17 15:43, Toke Høiland-Jørgensen wrote: > Felix Fietkau writes: > >> On 2016-06-17 11:09, Toke Høiland-Jørgensen wrote: >>> This patch leaves the code for ath9k's internal per-node per-tid >>> queues in place and just modifies the driver to also pull from >>> the new mac80211 intermediate software queues, and implements >>> the .wake_tx_queue method, which will cause mac80211 to deliver >>> packets to be sent via the new intermediate queue. >>> >>> Signed-off-by: Tim Shepard >>> >>> Reworked to not require the global variable renaming in ath9k. >>> >>> Signed-off-by: Toke Høiland-Jørgensen >>> --- >>> drivers/net/wireless/ath/ath9k/ath9k.h | 16 +++- >>> drivers/net/wireless/ath/ath9k/debug_sta.c | 7 +- >>> drivers/net/wireless/ath/ath9k/init.c | 1 + >>> drivers/net/wireless/ath/ath9k/main.c | 1 + >>> drivers/net/wireless/ath/ath9k/xmit.c | 119 +++++++++++++++++++++++++---- >>> 5 files changed, 125 insertions(+), 19 deletions(-) >>> >>> diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h >>> index 93b3793..caeae10 100644 >>> --- a/drivers/net/wireless/ath/ath9k/ath9k.h >>> +++ b/drivers/net/wireless/ath/ath9k/ath9k.h >>> @@ -145,8 +145,6 @@ int ath_descdma_setup(struct ath_softc *sc, struct ath_descdma *dd, >>> #define BAW_WITHIN(_start, _bawsz, _seqno) \ >>> ((((_seqno) - (_start)) & 4095) < (_bawsz)) >>> >>> -#define ATH_AN_2_TID(_an, _tidno) (&(_an)->tid[(_tidno)]) >>> - >>> #define IS_HT_RATE(rate) (rate & 0x80) >>> #define IS_CCK_RATE(rate) ((rate >= 0x18) && (rate <= 0x1e)) >>> #define IS_OFDM_RATE(rate) ((rate >= 0x8) && (rate <= 0xf)) >>> @@ -232,8 +230,10 @@ struct ath_buf { >>> >>> struct ath_atx_tid { >>> struct list_head list; >>> + struct sk_buff_head i_q; >> Do we really need a third queue here? Instead of adding yet another >> layer of queueing here, I think we should even get rid of buf_q. > > This is definitely something that needs to be improved. One other > sticking point related to this: in the current version of this patch > ath_tid_has_buffered() gains a side effect of pulling from the mac80211 > txq, which is obviously not so nice. > > The obvious way to get rid of this is to export a txq_has_buffered() > function at the mac80211 layer. But avoiding that may be possible; the > sticking point is what to do with the code paths that do not dequeue > packets, but check ath_tid_has_buffered() to decide whether to schedule > the queue and/or to tell ieee80211_sta_set_buffered() about it (these > are for instance ath_tx_aggr_sleep/wakeup(). Can those just be removed > (i.e. don't call into ieee80211, and always schedule the txq on wakeup? > I'm not familiar enough with the intermediate queues to make that > call... For tx scheduling, we can use swq_nonempty and deal with false positives. For power save we should only use ieee80211_sta_set_buffered if the driver itself has buffered some frames. Indication of packets in the mac80211 intermediate queue is already taken care of inside mac80211. - Felix