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

[Ben Greear]

On 01/27/2018 05:29 AM, Toke Høiland-Jørgensen wrote:

gree...@candelatech.com writes:

From: Ben Greear <gree...@candelatech.com>

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 <gree...@candelatech.com>
---
 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 <gree...@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com