Hi Erik,
We have met performance issue on our two-core system after applying your
patch. In WDS mode, we found that the peak throughput in TCP-DL and
UDP-DL dropped more than 10% compared with previous one. And in some
cases, though throughput stays the same, one CPU usage rises about 20%
which leads to 10% in total CPU usage. With your change, I think driver
will try its best to push as many packets as it can. During this time,
the driver's queue lock will be held for too much time in one CPU and as
a result, the other CPU will be blocked if it wants to acquired the same
lock. Working in this way seems not efficiency.
So I think it is better to revert the change till we come up with a new
solution.
Subject: [PATCH] ath10k: fix return value check in wake_tx_q op
ath10k_mac_tx_push_txq returns either a postive integer (length) on
success
or a negative error code on error.
The "if (ret) break;" statement will thus always break out of the
loop
immediately after ath10k_mac_tx_push_txq has returned (making the
loop
pointless).
A side effect of this fix is that we will iterate the queue until
ath10k_mac_tx_push_txq returns -ENOENT. This will make sure the queue
is
not added back to ar->txqs when it is empty. This could potentially
improve
performance somewhat (I have seen a small improvement with SDIO
devices).
Signed-off-by: Erik Stromdahl <[email protected]>
---
drivers/net/wireless/ath/ath10k/mac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c
b/drivers/net/wireless/ath/ath10k/mac.c
index 3d7119ad7c7a..487a7a7380fd 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -4290,7 +4290,7 @@ static void ath10k_mac_op_wake_tx_queue(struct
ieee80211_hw *hw,
while (ath10k_mac_tx_can_push(hw, f_txq) && max--) {
ret = ath10k_mac_tx_push_txq(hw, f_txq);
- if (ret)
+ if (ret < 0)
break;
}
if (ret != -ENOENT)
--
2.17.0
--
yibo
- Re: FW: [PATCH] ath10k: fix return value check in wake_tx_q op yiboz
-
