Hello,
I have the following problem:

[  296.337510] ------------[ cut here ]------------
[  296.337523] WARNING: at net/sched/sch_generic.c:255 dev_watchdog+0xc1/0x125()
[  296.337527] Hardware name: F3JC                
[  296.337530] NETDEV WATCHDOG: eth0 (r8169): transmit queue 0 timed out
[  296.337533] Modules linked in: pktgen ipv6 snd_hwdep snd_hda_codec_si3054 snd_hda_codec_realtek sdhci_pci sdhci asus_laptop sparse_keymap mmc_core led_class snd_hda_intel
snd_hda_codec psmouse snd_pcm snd_timer snd soundcore snd_page_alloc serio_raw i2c_i801 rng_core evdev sg r8169 mii usbhid hid uhci_hcd ehci_hcd sr_mod cdrom sd_mod usbcore
ata_piix
[  296.337586] Pid: 0, comm: swapper Not tainted 2.6.34-rc3-dbg #74
[  296.337589] Call Trace:
[  296.337597]  [<c102e71f>] warn_slowpath_common+0x65/0x7c
[  296.337603]  [<c126e30c>] ? dev_watchdog+0xc1/0x125
[  296.337608]  [<c102e76a>] warn_slowpath_fmt+0x24/0x27
[  296.337613]  [<c126e30c>] dev_watchdog+0xc1/0x125
[  296.337620]  [<c1040039>] ? prepare_to_wait_exclusive+0x52/0x5b
[  296.337627]  [<c1037053>] ? run_timer_softirq+0x120/0x1eb
[  296.337632]  [<c10370a9>] run_timer_softirq+0x176/0x1eb
[  296.337637]  [<c1037053>] ? run_timer_softirq+0x120/0x1eb
[  296.337643]  [<c126e24b>] ? dev_watchdog+0x0/0x125
[  296.337650]  [<c10331c9>] __do_softirq+0x8d/0x117
[  296.337655]  [<c103327e>] do_softirq+0x2b/0x43
[  296.337660]  [<c10333a3>] irq_exit+0x38/0x75
[  296.337667]  [<c1015138>] smp_apic_timer_interrupt+0x6d/0x7b
[  296.337673]  [<c12cbada>] apic_timer_interrupt+0x36/0x3c
[  296.337679]  [<c104007b>] ? prepare_to_wait+0x39/0x57
[  296.337685]  [<c11dd835>] ? acpi_idle_enter_simple+0x119/0x144
[  296.337692]  [<c124d358>] cpuidle_idle_call+0x6d/0xa5
[  296.337697]  [<c1001b51>] cpu_idle+0x92/0xc1
[  296.337704]  [<c12c63d0>] start_secondary+0x1f3/0x1fa
[  296.337708] ---[ end trace cd4a1b50139837df ]---


Reproducing 100% with pktgen tests.


	Sergey