Re: [PATCH] ath9k: Print has_queued in debugfs.

[Ben Greear <greearb@xxxxxxxxxxxxxxx>]

On 01/27/2018 05:29 AM, Toke Høiland-Jørgensen wrote:
> greearb@xxxxxxxxxxxxxxx writes:
>
> > From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
> >
> > The PAUSED field was never printed per tid.  Replace that
> > with has_queued, which might help someone track down strange
> > bugs related to aqm.
> >
> > And, make tx-queue debug info show peer BSSID as well as vdev
> > MAC to aid debugging with multiple stations connected to the
> > same peer.
> >
> > Signed-off-by: Ben Greear <greearb@xxxxxxxxxxxxxxx>
> > ---
> >  drivers/net/wireless/ath/ath9k/debug_sta.c | 10 ++++++----
> >  drivers/net/wireless/ath/ath9k/xmit.c      |  5 +++--
> >  2 files changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ath/ath9k/debug_sta.c b/drivers/net/wireless/ath/ath9k/debug_sta.c
> > index efc692e..a45f1f5 100644
> > --- a/drivers/net/wireless/ath/ath9k/debug_sta.c
> > +++ b/drivers/net/wireless/ath/ath9k/debug_sta.c
> > @@ -48,9 +48,10 @@ static ssize_t read_file_node_aggr(struct file *file, char __user *user_buf,
> >  			 an->mpdudensity);
> >
> >  	len += scnprintf(buf + len, size - len,
> > -			 "\n%3s%11s%10s%10s%10s%10s%9s%6s%8s\n",
> > +			 "\n%3s%11s%10s%10s%10s%10s%9s%6s%9s\n",
> >  			 "TID", "SEQ_START", "SEQ_NEXT", "BAW_SIZE",
> > -			 "BAW_HEAD", "BAW_TAIL", "BAR_IDX", "SCHED", "PAUSED");
> > +			 "BAW_HEAD", "BAW_TAIL", "BAR_IDX", "SCHED",
> > +			 "HAS-QUED");
> >
> >  	for (tidno = 0; tidno < IEEE80211_NUM_TIDS; tidno++) {
> >  		tid = ath_node_to_tid(an, tidno);
> > @@ -58,7 +59,7 @@ static ssize_t read_file_node_aggr(struct file *file, char __user *user_buf,
> >  		ath_txq_lock(sc, txq);
> >  		if (tid->active) {
> >  			len += scnprintf(buf + len, size - len,
> > -					 "%3d%11d%10d%10d%10d%10d%9d%6d\n",
> > +					 "%3d%11d%10d%10d%10d%10d%9d%6d%9d\n",
> >  					 tid->tidno,
> >  					 tid->seq_start,
> >  					 tid->seq_next,
> > @@ -66,7 +67,8 @@ static ssize_t read_file_node_aggr(struct file *file, char __user *user_buf,
> >  					 tid->baw_head,
> >  					 tid->baw_tail,
> >  					 tid->bar_index,
> > -					 !list_empty(&tid->list));
> > +					 !list_empty(&tid->list),
> > +					 tid->has_queued);
>
> Would it perhaps be useful to print the length of tid->retry_q instead
> of / in addition to has_queued? Planning to get rid of the has_queued
> variable entirely...

I'm just getting started looking at this.  4.9 kernel works fine, so it seems
to be a regression in the aqm stuff since that is the big change between 4.9
and 4.13.

From a brief look yesterday, it seems that has_queued is not adequately protected
by locks, but also, it was '1', which indicates it wants to send pkts (?), so I guess
it was not hitting a locking race.

Can you point me at the scheduler code (method name?).  I'll be looking at that
as soon as I get time.

Thanks,
Ben

> -Toke

--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc  http://www.candelatech.com