ath10k performance, master branch from 20160407

Manoharan, Rajkumar rmanohar at qti.qualcomm.com
Sun Apr 17 08:06:14 PDT 2016


Roman,

Hmm.. I just listed ath10k changes alone. So there might be some dependencies.
In your earlier mail fq_codel_drop was consuming 45% cpu. Have you observed any
improvement after switching off NET_SCH_FQ_CODEL? Had CPU usage gone down?

Please try to revert the commit "ath10k: combine txrx and replenish task" alone. If you still
see same behavior (lower numbers), reset master branch to till "ath10k: fix pull-push tx
threshold handling" and generate backports.

Please make sure that codel is switched off always until regression point is root caused.

-Rajkumar

________________________________________
From: Roman Yeryomin <leroi.lists at gmail.com>
Sent: Sunday, April 17, 2016 2:58 PM
To: Manoharan, Rajkumar
Cc: ath10k at lists.infradead.org; Rajkumar Manoharan
Subject: Re: ath10k performance, master branch from 20160407

Rajkumar,

Somehow unseting CPTCFG_NET_SCH_FQ_CODEL didn't change anything and
the patches you listed didn't revert cleanly, I gave up on 3rd
dependent patch somewhere in the middle and just reset master to
89ef41bfaa46f24a14b776f1cd78c0e0b39e54ce, which is the last commit
just before "ath10k: refactor tx code", and generated new backports.
The result is that it has same performance as before. But I guess it
is not a very good test as there were many changes to mac80211 too.

So what do you want me to try next? Maybe you could provide a more
precise list to revert?


Regards,
Roman

On 9 April 2016 at 07:02, Manoharan, Rajkumar <rmanohar at qti.qualcomm.com> wrote:
> Roman,
>
> Need your help to bisect regression point. Can you try w/o CPTCFG_NET_SCH_FQ_CODEL?
> If it does not help, try reverting below commits which are major changes in data path.
> Instead of generating backports, apply revert commit on top your backports.
>
> ath10k: combine txrx and replenish task
> ath10k: reuse copy engine 5 (htt rx) descriptors
> ath10k: cleanup copy engine receive next completion
> ath10k: register ath10k_htt_htc_t2h_msg_handler
> ath10k: speedup htt rx descriptor processing for rx_ind
> ath10k: cleanup amsdu processing for rx indication
> ath10k: remove unused fw_desc processing
> ath10k: copy tx fetch indication message
> ath10k: speedup htt rx descriptor processing for tx completion
> ath10k: fix null deref if device crashes early
> ath10k: fix pull-push tx threshold handling
> ath10k: fix tx hang
> ath10k: move mgmt descriptor limit handle under mgmt_tx
> ath10k: change htt tx desc/qcache peer limit config
> ath10k: fix HTT Tx CE ring size
> ath10k: implement push-pull tx
> ath10k: keep track of queue depth per txq
> ath10k: store txq in skb_cb
> ath10k: implement updating shared htt txq state
> ath10k: implement wake_tx_queue
> ath10k: add new htt message generation/parsing logic
> ath10k: add fast peer_map lookup
> ath10k: maintain peer_id for each sta and vif
> ath10k: refactor tx pending management
> ath10k: unify txpath decision
> ath10k: refactor tx code
>
> -Rajkumar
> ________________________________________
> From: Roman Yeryomin <leroi.lists at gmail.com>
> Sent: Friday, April 8, 2016 10:49 PM
> To: Manoharan, Rajkumar
> Cc: ath10k at lists.infradead.org; Rajkumar Manoharan
> Subject: Re: ath10k performance, master branch from 20160407
>
> Latest backports (compat-wireless) released (20160110) has codel
> enabled (CPTCFG_NET_SCH_FQ_CODEL=y) and there are no openwrt patches
> or special configuration for codel. And it runs ok.
> How old commit do you want me to try?
>
> Regards,
> Roman
>
> On 8 April 2016 at 19:41, Manoharan, Rajkumar <rmanohar at qti.qualcomm.com> wrote:
>> That should be fine. Is codel running only for latest backports? Are there any openwrt changes to configure codel? Can you plz try to reset master branch to older commit and validate?
>>
>> -Rajkumar
>> ________________________________________
>> From: Roman Yeryomin [leroi.lists at gmail.com]
>> Sent: Friday, April 8, 2016 9:30 PM
>> To: Manoharan, Rajkumar
>> Cc: ath10k at lists.infradead.org; Rajkumar Manoharan
>> Subject: Re: ath10k performance, master branch from 20160407
>>
>> Rajkumar,
>>
>> I took backports from
>> git://git.kernel.org/pub/scm/linux/kernel/git/backports/backports.git,
>> took latest ath tree from
>> git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git, generated
>> backports-output based on ath master branch, refreshed openwrt
>> patches.
>> And saw big performance degradation. Am I doing something wrong?
>>
>> Regards,
>> Roman
>>
>> On 8 April 2016 at 18:34, Manoharan, Rajkumar <rmanohar at qti.qualcomm.com> wrote:
>>> Roman,
>>>
>>> Which backports version are you using? I don't see codel changes in ath.git/wireless-drivers.git.
>>> Hope you are using same firmware.
>>>
>>> -Rajkumar
>>> ________________________________________
>>> From: ath10k <ath10k-bounces at lists.infradead.org> on behalf of Roman Yeryomin <leroi.lists at gmail.com>
>>> Sent: Friday, April 8, 2016 8:14 PM
>>> To: ath10k at lists.infradead.org
>>> Subject: ath10k performance, master branch from 20160407
>>>
>>> Hello!
>>>
>>> I've seen performance patches were commited so I've decided to give it
>>> a try (using 4.1 kernel and backports).
>>> The results are quite disappointing: TCP download (client pov) dropped
>>> from 750Mbps to ~550 and UDP shows completely weird behavour - if
>>> generating 900Mbps it gives 30Mbps max, if generating 300Mbps it gives
>>> 250Mbps, before (latest official backports release from January) I was
>>> able to get 900Mbps.
>>> Hardware is basically ap152 + qca988x 3x3.
>>> When running perf top I see that fq_codel_drop eats a lot of cpu.
>>> Here is the output when running iperf3 UDP test:
>>>
>>>     45.78%  [kernel]       [k] fq_codel_drop
>>>      3.05%  [kernel]       [k] ag71xx_poll
>>>      2.18%  [kernel]       [k] skb_release_data
>>>      2.01%  [kernel]       [k] r4k_dma_cache_inv
>>>      1.73%  [kernel]       [k] eth_type_trans
>>>      1.24%  [kernel]       [k] build_skb
>>>      1.20%  [mac80211]     [k] ieee80211_tx_dequeue
>>>      1.03%  [kernel]       [k] __delay
>>>      0.98%  [kernel]       [k] fq_codel_enqueue
>>>      0.94%  [kernel]       [k] __netif_receive_skb_core
>>>      0.93%  [kernel]       [k] skb_release_head_state
>>>      0.88%  [ath10k_core]  [k] ath10k_htt_tx
>>>      0.87%  [kernel]       [k] __dev_queue_xmit
>>>      0.84%  [mac80211]     [k] ieee80211_tx_status
>>>      0.81%  [kernel]       [k] __build_skb
>>>      0.80%  [mac80211]     [k] __ieee80211_subif_start_xmit
>>>      0.77%  [kernel]       [k] br_handle_frame_finish
>>>      0.75%  [kernel]       [k] __qdisc_run
>>>      0.73%  [kernel]       [k] skb_recycler_consume
>>>      0.72%  [kernel]       [k] kfree_skb
>>>      0.72%  [kernel]       [k] get_page_from_freelist
>>>      0.69%  [kernel]       [k] br_fdb_update
>>>      0.69%  [kernel]       [k] br_handle_frame
>>>      0.67%  [kernel]       [k] __copy_user_common
>>>      0.66%  [kernel]       [k] __skb_flow_dissect
>>>      0.65%  [ath10k_core]  [k] ath10k_txrx_tx_unref
>>>      0.60%  [kernel]       [k] kmem_cache_alloc
>>>      0.60%  [mac80211]     [k] sta_addr_hash
>>>      0.56%  [kernel]       [k] fq_codel_dequeue
>>>      0.53%  [kernel]       [k] __local_bh_enable_ip
>>>      0.50%  [kernel]       [k] __br_fdb_get
>>>
>>> What could be the reason?
>>> I've seen there are some patches from Michal which touch fq_codel,
>>> would those help or not?
>>>
>>>
>>> Regards,
>>> Roman
>>>
>>> _______________________________________________
>>> ath10k mailing list
>>> ath10k at lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/ath10k


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