2007-05-21 19:50:34

by Chris Wright

[permalink] [raw]
Subject: [patch 32/69] NETPOLL: Fix TX queue overflow in trapped mode.

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Sergei Shtylyov <[email protected]>

CONFIG_NETPOLL_TRAP causes the TX queue controls to be completely bypassed in
the netpoll's "trapped" mode which easily causes overflows in the drivers with
short TX queues (most notably, in 8139too with its 4-deep queue). So, make
this option more sensible by making it only bypass the TX softirq wakeup.

Signed-off-by: Sergei Shtylyov <[email protected]>
Acked-by: Jeff Garzik <[email protected]>
Acked-by: Tom Rini <[email protected]>
Acked-by: Matt Mackall <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
include/linux/netdevice.h | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

--- linux-2.6.21.1.orig/include/linux/netdevice.h
+++ linux-2.6.21.1/include/linux/netdevice.h
@@ -647,8 +647,10 @@ static inline void netif_start_queue(str
static inline void netif_wake_queue(struct net_device *dev)
{
#ifdef CONFIG_NETPOLL_TRAP
- if (netpoll_trap())
+ if (netpoll_trap()) {
+ clear_bit(__LINK_STATE_XOFF, &dev->state);
return;
+ }
#endif
if (test_and_clear_bit(__LINK_STATE_XOFF, &dev->state))
__netif_schedule(dev);
@@ -656,10 +658,6 @@ static inline void netif_wake_queue(stru

static inline void netif_stop_queue(struct net_device *dev)
{
-#ifdef CONFIG_NETPOLL_TRAP
- if (netpoll_trap())
- return;
-#endif
set_bit(__LINK_STATE_XOFF, &dev->state);
}


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