Re: commit 6dccd16b7c2703e8bbf8bca62b5cf248332afbe2 kills r8169 send performance

From: Francois Romieu
Date: Wed Sep 26 2007 - 13:11:16 EST


Timo Jantunen <jeti@xxxxxxxxx> :
[...]
> Git bisect gave commit 6dccd16b7c2703e8bbf8bca62b5cf248332afbe2 as the
> culprit, and reverting it from the 2.6.23-rc8 increases send speed back to
> .22 level. (It didn't revert cleanly and the file needed some cleaning up
> by hand.)

You are welcome but you are late.

The patch below is scheduled for inclusion before 2.6.23. Please try it and
see if it makes a difference on top of 2.6.23-rc8 (full dmesg will be welcome
too).

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index b85ab4a..c921ec3 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -1228,7 +1228,10 @@ static void rtl8169_hw_phy_config(struct net_device *dev)
return;
}

- /* phy config for RTL8169s mac_version C chip */
+ if ((tp->mac_version != RTL_GIGA_MAC_VER_02) &&
+ (tp->mac_version != RTL_GIGA_MAC_VER_03))
+ return;
+
mdio_write(ioaddr, 31, 0x0001); //w 31 2 0 1
mdio_write(ioaddr, 21, 0x1000); //w 21 15 0 1000
mdio_write(ioaddr, 24, 0x65c7); //w 24 15 0 65c7
@@ -2567,6 +2570,15 @@ static void rtl8169_tx_interrupt(struct net_device *dev,
(TX_BUFFS_AVAIL(tp) >= MAX_SKB_FRAGS)) {
netif_wake_queue(dev);
}
+ /*
+ * 8168 hack: TxPoll requests are lost when the Tx packets are
+ * too close. Let's kick an extra TxPoll request when a burst
+ * of start_xmit activity is detected (if it is not detected,
+ * it is slow enough). -- FR
+ */
+ smp_rmb();
+ if (tp->cur_tx != dirty_tx)
+ RTL_W8(TxPoll, NPQ);
}
}

--
Ueimor
-
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