Hi Eddie/All,
I think ToDevice() needs to use dev_queue_xmit() to update txq->trans_start and
avoid dev_watchdog's wrong netdev resetting.
Please review patch below.
Thanks,
Joonwoo
>From 77d8981ae8735c7ae08a87d9c334eb230e946010 Mon Sep 17 00:00:00 2001
From: Joonwoo Park <joonwpar...@gmail.com>
Date: Wed, 23 Feb 2011 22:49:46 -0800
Subject: [PATCH] ToDevice/linuxmodule: Transmit skb with dev_queue_xmit()
If ToDevice sends skbs fast enough so TX desc of netdev is full,
device driver can request stop queuing by calling netif_stop_queue().
In that case dev_watchdog() will think netdev's TX is hung because
txq->trans_start is never updated by ToDevice().
To update txq->trans_start, ToDevice needs to use dev_queue_xmit()
This fixes periodic watchdog timeout:
[ 101.895978] ------------[ cut here ]------------
[ 101.897175] WARNING: at net/sched/sch_generic.c:266
dev_watchdog+0x1d6/0x288()
[ 101.898728] Hardware name: Bochs
[ 101.899389] NETDEV WATCHDOG: eth1 (e1000e): transmit queue 0 timed out
[ 101.900768] Modules linked in: click proclikefs e1000e
[ 101.902532] Pid: 552, comm: kclick Not tainted 2.6.37+ #35
[ 101.904416] Call Trace:
[ 101.905264] <IRQ> [<ffffffff81082946>] warn_slowpath_common+0x80/0x98
[ 101.907012] [<ffffffff810829f2>] warn_slowpath_fmt+0x41/0x43
[ 101.908146] [<ffffffff8143aeee>] dev_watchdog+0x1d6/0x288
[ 101.909225] [<ffffffff810c5a8e>] ? handle_edge_irq+0x187/0x195
[ 101.910370] [<ffffffff814218e5>] ? __napi_complete+0x28/0x31
[ 101.911739] [<ffffffff8108f726>] run_timer_softirq+0x20e/0x300
[ 101.913106] [<ffffffff8143ad18>] ? dev_watchdog+0x0/0x288
[ 101.914498] [<ffffffff81088c26>] __do_softirq+0xe1/0x1b7
[ 101.915462] [<ffffffff8103fb9c>] call_softirq+0x1c/0x30
[ 101.916659] [<ffffffff81041359>] do_softirq+0x61/0xbf
[ 101.917657] [<ffffffff810885ca>] irq_exit+0x36/0x38
[ 101.919697] [<ffffffff8105b13b>] smp_apic_timer_interrupt+0x88/0x96
[ 101.920563] [<ffffffff8103f653>] apic_timer_interrupt+0x13/0x20
Signed-off-by: Joonwoo Park <joonwpar...@gmail.com>
---
elements/linuxmodule/todevice.cc | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/elements/linuxmodule/todevice.cc b/elements/linuxmodule/todevice.cc
index dbef920..5985871 100644
--- a/elements/linuxmodule/todevice.cc
+++ b/elements/linuxmodule/todevice.cc
@@ -503,8 +503,7 @@ ToDevice::queue_packet(Packet *p, struct netdev_queue *txq)
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 30)
- // XXX should we call dev_hard_start_xmit??? Probably
- ret = dev->netdev_ops->ndo_start_xmit(skb1, dev);
+ ret = dev_queue_xmit(skb1);
#else
ret = dev->hard_start_xmit(skb1, dev);
#endif
--
1.7.1
_______________________________________________
click mailing list
click@amsterdam.lcs.mit.edu
https://amsterdam.lcs.mit.edu/mailman/listinfo/click
