Since commit a8bb74acd8 ("rcu: Consolidate RCU-sched update-side function definitions")
there is no difference between rcu_read_lock(), rcu_read_lock_bh() and
rcu_read_lock_sched() in terms of RCU read section and the relevant grace
period. That means that spin_lock(), which implies rcu_read_lock_sched(),
also implies rcu_read_lock().
There is no need no explicitly start a RCU read section if one has already
been started implicitly by spin_lock().
Simplify the code and remove the inner rcu_read_lock() invocation.
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
Signed-off-by: pengdonglin <dolinux.peng@gmail.com>
Link: https://patch.msgid.link/20250916044735.2316171-11-dolinux.peng@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This reverts commit 484a54c2e5. The CoDel
parameter change essentially disables CoDel on slow stations, with some
questionable assumptions, as Dave pointed out in [0]. Quoting from
there:
But here are my pithy comments as to why this part of mac80211 is so
wrong...
static void sta_update_codel_params(struct sta_info *sta, u32 thr)
{
- if (thr && thr < STA_SLOW_THRESHOLD * sta->local->num_sta) {
1) sta->local->num_sta is the number of associated, rather than
active, stations. "Active" stations in the last 50ms or so, might have
been a better thing to use, but as most people have far more than that
associated, we end up with really lousy codel parameters, all the
time. Mistake numero uno!
2) The STA_SLOW_THRESHOLD was completely arbitrary in 2016.
- sta->cparams.target = MS2TIME(50);
This, by itself, was probably not too bad. 30ms might have been
better, at the time, when we were battling powersave etc, but 20ms was
enough, really, to cover most scenarios, even where we had low rate
2Ghz multicast to cope with. Even then, codel has a hard time finding
any sane drop rate at all, with a target this high.
- sta->cparams.interval = MS2TIME(300);
But this was horrible, a total mistake, that is leading to codel being
completely ineffective in almost any scenario on clients or APS.
100ms, even 80ms, here, would be vastly better than this insanity. I'm
seeing 5+seconds of delay accumulated in a bunch of otherwise happily
fq-ing APs....
100ms of observed jitter during a flow is enough. Certainly (in 2016)
there were interactions with powersave that I did not understand, and
still don't, but if you are transmitting in the first place, powersave
shouldn't be a problemmmm.....
- sta->cparams.ecn = false;
At the time we were pretty nervous about ecn, I'm kind of sanguine
about it now, and reliably indicating ecn seems better than turning it
off for any reason.
[...]
In production, on p2p wireless, I've had 8ms and 80ms for target and
interval for years now, and it works great.
I think Dave's arguments above are basically sound on the face of it,
and various experimentation with tighter CoDel parameters in the OpenWrt
community have show promising results[1]. So I don't think there's any
reason to keep this parameter fiddling; hence this revert.
[0] https://lore.kernel.org/linux-wireless/CAA93jw6NJ2cmLmMauz0xAgC2MGbBq6n0ZiZzAdkK0u4b+O2yXg@mail.gmail.com/
[1] https://forum.openwrt.org/t/reducing-multiplexing-latencies-still-further-in-wifi/133605/130
Suggested-By: Dave Taht <dave.taht@gmail.com>
In-memory-of: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20250403183930.197716-1-toke@toke.dk
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The read is currently with RCU and the write can deadlock,
convert both for the sake of illustration.
Make mac80211 depend on cfg80211 debugfs to get the helpers,
but mac80211 debugfs without it does nothing anyway. This
also required some adjustments in ath9k.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When a running wake_tx_queue() call is aborted due to a hw queue stop
the corresponding iTXQ is not always correctly marked for resumption:
wake_tx_push_queue() can stops the queue run without setting
@IEEE80211_TXQ_STOP_NETIF_TX.
Without the @IEEE80211_TXQ_STOP_NETIF_TX flag __ieee80211_wake_txqs()
will not schedule a new queue run and remaining frames in the queue get
stuck till another frame is queued to it.
Fix the issue for all drivers - also the ones with custom wake_tx_queue
callbacks - by moving the logic into ieee80211_tx_dequeue() and drop the
redundant @txqs_stopped.
@IEEE80211_TXQ_STOP_NETIF_TX is also renamed to @IEEE80211_TXQ_DIRTY to
better describe the flag.
Fixes: c850e31f79 ("wifi: mac80211: add internal handler for wake_tx_queue")
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20221230121850.218810-1-alexander@wetzel-home.de
Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
All drivers are now using mac80211 internal queues (iTXQs).
Drop mac80211 internal support for the old push path.
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add the link address to the per-link information, but only if we are
using MLO.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Create debugfs data per-link. For drivers, there is a new operation
link_sta_add_debugfs which will always be called.
For non-MLO, the station directory will be used directly rather than
creating a corresponding subdirectory. As such, non-MLO drivers can
simply continue to create the data from sta_debugfs_add.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
[add missing inlines if !CONFIG_MAC80211_DEBUGFS]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This reverts commits 6a789ba679 and
2433647bc8.
The virtual time scheduler code has a number of issues:
- queues slowed down by hardware/firmware powersave handling were not properly
handled.
- on ath10k in push-pull mode, tx queues that the driver tries to pull from
were starved, causing excessive latency
- delay between tx enqueue and reported airtime use were causing excessively
bursty tx behavior
The bursty behavior may also be present on the round-robin scheduler, but there
it is much easier to fix without introducing additional regressions
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://lore.kernel.org/r/20220625212411.36675-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Kalle Valo says:
====================
wireless-next patches for v5.19
First set of patches for v5.19 and this is a big one. We have two new
drivers, a change in mac80211 STA API affecting most drivers and
ath11k getting support for WCN6750. And as usual lots of fixes and
cleanups all over.
Major changes:
new drivers
- wfx: silicon labs devices
- plfxlc: pureLiFi X, XL, XC devices
mac80211
- host based BSS color collision detection
- prepare sta handling for IEEE 802.11be Multi-Link Operation (MLO) support
rtw88
- support TP-Link T2E devices
rtw89
- support firmware crash simulation
- preparation for 8852ce hardware support
ath11k
- Wake-on-WLAN support for QCA6390 and WCN6855
- device recovery (firmware restart) support for QCA6390 and WCN6855
- support setting Specific Absorption Rate (SAR) for WCN6855
- read country code from SMBIOS for WCN6855/QCA6390
- support for WCN6750
wcn36xx
- support for transmit rate reporting to user space
* tag 'wireless-next-2022-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next: (228 commits)
rtw89: 8852c: rfk: add DPK
rtw89: 8852c: rfk: add IQK
rtw89: 8852c: rfk: add RX DCK
rtw89: 8852c: rfk: add RCK
rtw89: 8852c: rfk: add TSSI
rtw89: 8852c: rfk: add LCK
rtw89: 8852c: rfk: add DACK
rtw89: 8852c: rfk: add RFK tables
plfxlc: fix le16_to_cpu warning for beacon_interval
rtw88: remove a copy of the NAPI_POLL_WEIGHT define
carl9170: tx: fix an incorrect use of list iterator
wil6210: use NAPI_POLL_WEIGHT for napi budget
ath10k: remove a copy of the NAPI_POLL_WEIGHT define
ath11k: Add support for WCN6750 device
ath11k: Datapath changes to support WCN6750
ath11k: HAL changes to support WCN6750
ath11k: Add QMI changes for WCN6750
ath11k: Fetch device information via QMI for WCN6750
ath11k: Add register access logic for WCN6750
ath11k: Add HW params for WCN6750
...
====================
Link: https://lore.kernel.org/r/20220503153622.C1671C385A4@smtp.kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently in mac80211 each STA object is represented
using sta_info datastructure with the associated
STA specific information and drivers access ieee80211_sta
part of it.
With MLO (Multi Link Operation) support being added
in 802.11be standard, though the association is logically
with a single Multi Link capable STA, at the physical level
communication can happen via different advertised
links (uniquely identified by Channel, operating class,
BSSID) and hence the need to handle multiple link
STA parameters within a composite sta_info object
called the MLD STA. The different link STA part of
MLD STA are identified using the link address which can
be same or different as the MLD STA address and unique
link id based on the link vif.
To support extension of such a model, the sta_info
datastructure is modified to hold multiple link STA
objects with link specific params currently within
sta_info moved to this new structure. Similarly this is
done for ieee80211_sta as well which will be accessed
within mac80211 as well as by drivers, hence trivial
driver changes are expected to support this.
For current non MLO supported drivers, only one link STA
is present and link information is accessed via 'deflink'
member.
For MLO drivers, we still need to define the APIs etc. to
get the correct link ID and access the correct part of
the station info.
Currently in mac80211, all link STA info are accessed directly
via deflink. These will be updated to access via link pointers
indexed by link id with MLO support patches, with link id
being 0 for non MLO supported cases.
Except for couple of macro related changes, below spatch takes
care of updating mac80211 and driver code to access to the
link STA info via deflink.
@ieee80211_sta@
struct ieee80211_sta *s;
struct sta_info *si;
identifier var = {supp_rates, ht_cap, vht_cap, he_cap, he_6ghz_capa, eht_cap, rx_nss, bandwidth, txpwr};
@@
(
s->
- var
+ deflink.var
|
si->sta.
- var
+ deflink.var
)
@sta_info@
struct sta_info *si;
identifier var = {gtk, pcpu_rx_stats, rx_stats, rx_stats_avg, status_stats, tx_stats, cur_max_bandwidth};
@@
(
si->
- var
+ deflink.var
)
Signed-off-by: Sriram R <quic_srirrama@quicinc.com>
Link: https://lore.kernel.org/r/1649086883-13246-1-git-send-email-quic_srirrama@quicinc.com
[remove MLO-drivers notes from commit message, not clear yet; run spatch]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This switches the airtime scheduler in mac80211 to use a virtual
time-based scheduler instead of the round-robin scheduler used before.
This has a couple of advantages:
- No need to sync up the round-robin scheduler in firmware/hardware with
the round-robin airtime scheduler.
- If several stations are eligible for transmission we can schedule both
of them; no need to hard-block the scheduling rotation until the head
of the queue has used up its quantum.
- The check of whether a station is eligible for transmission becomes
simpler (in ieee80211_txq_may_transmit()).
The drawback is that scheduling becomes slightly more expensive, as we
need to maintain an rbtree of TXQs sorted by virtual time. This means
that ieee80211_register_airtime() becomes O(logN) in the number of
currently scheduled TXQs because it can change the order of the
scheduled stations. We mitigate this overhead by only resorting when a
station changes position in the tree, and hopefully N rarely grows too
big (it's only TXQs currently backlogged, not all associated stations),
so it shouldn't be too big of an issue.
To prevent divisions in the fast path, we maintain both station sums and
pre-computed reciprocals of the sums. This turns the fast-path operation
into a multiplication, with divisions only happening as the number of
active stations change (to re-compute the current sum of all active
station weights). To prevent this re-computation of the reciprocal from
happening too frequently, we use a time-based notion of station
activity, instead of updating the weight every time a station gets
scheduled or de-scheduled. As queues can oscillate between empty and
occupied quite frequently, this can significantly cut down on the number
of re-computations. It also has the added benefit of making the station
airtime calculation independent on whether the queue happened to have
drained at the time an airtime value was accounted.
Co-developed-by: Yibo Zhao <yiboz@codeaurora.org>
Signed-off-by: Yibo Zhao <yiboz@codeaurora.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20210623134755.235545-1-toke@redhat.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This allows drivers to pass 802.3 frames to mac80211, with some restrictions:
- the skb must be passed with a valid sta
- fast-rx needs to be active for the sta
- monitor mode needs to be disabled
mac80211 will tell the driver when it is safe to enable rx decap offload for
a particular station.
In order to implement support, a driver must:
- call ieee80211_hw_set(hw, SUPPORTS_RX_DECAP_OFFLOAD)
- implement ops->sta_set_decap_offload
- mark 802.3 frames with RX_FLAG_8023
If it doesn't want to enable offload for some vif types, it can mask out
IEEE80211_OFFLOAD_DECAP_ENABLED in vif->offload_flags from within the
.add_interface or .update_vif_offload driver ops
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20201218184718.93650-6-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
