Filtering unwanted packets at ethernet interface level

[Amit Walambe]

Dear all,
I used the powertop utility about a month back and it got me completely
hooked. The efforts to go efficient made me change from GNOME to
Xfce and getting rid of mouse usage as much as possible amongst many
other things.

Continuing my obsession ;) :  currently on my machine 'wakeups-from-idle
per second' are somewhere between 35 and 40 during 'idle' times. (By
idle I mean user-idle; only background tasks running)
The main cause of this being the Broadcomm Tigon diver waking up
because of the 'Intel ANS probe' packets on our network.

That brings me to the question : Is there any way in Linux kernel so
that we can filter out unwanted packets at the physical layer, rather
than to bring them up all the way to network stack?

I tried looking for datasheets and then kernel documentation/code to
find if there is any way, but was largely unsuccessful.

I know this question might not be very relevant for this list and
might not even be possible thing, specially that the hardware is
question is very ordinary one. But 'powertop' brought it to my
attention really and it's part of my power-saving efforts so thought I
might ask. Any pointers/suggestions will be most welcome.

For those interested, following is (a very messed up) capture of
powertop. Also, kindly cc me to all the replies, as I am not subscribed
to the list.
Waiting for replies,
Thanks and Regards,
- Amit



     PowerTOP version 1.7       (C) 2007 Intel Corporation

< Detailed C-state information is only available on Mobile CPUs
(laptops) >

                                        1500 Mhz   ( 0.0%)
                                        1125 Mhz   ( 0.0%)
                                         750 Mhz   ( 0.0%)
                                         375 Mhz   (100.0%)

Wakeups-from-idle per second : 33.9     interval: 10.0s


Top causes for wakeups:
  39.1% ( 15.9)       <interrupt> : uhci_hcd:usb1, eth0 
  24.6% ( 10.0)          ifconfig : tg3_open (tg3_timer) 
   4.9% (  2.0)   xfce-mcs-manage : schedule_timeout (process_timeout)
   4.9% (  2.0)     <kernel core> : clocksource_register
(clocksource_watchdog) 
2.7% (  1.1)     <kernel core> : neigh_table_init_no_netlink
(neigh_periodic_timer) 
2.5% (  1.0)
xfce4-terminal : schedule_timeout (process_timeout) 
2.5%
(  1.0)          rc.local : queue_delayed_work_on
(delayed_work_timer_fn) 
2.5% (  1.0)             s2ram :
queue_delayed_work_on (delayed_work_timer_fn) 
2.5% (  1.0)
minicom : schedule_timeout (process_timeout) 
2.5% (  1.0)     <kernel core> : queue_delayed_work_on
(delayed_work_timer_fn) 
2.2% (  0.9)         konqueror : schedule_timeout (process_timeout)
1.2% (  0.5)              slim : do_setitimer (it_real_fn)
   1.2% (  0.5)            evince : schedule_timeout (process_timeout)
   0.7% (  0.3)         xfdesktop : schedule_timeout (process_timeout)
   0.7% (  0.3)            pidgin : schedule_timeout (process_timeout)
   0.5% (  0.2)              init : schedule_timeout (process_timeout)
   0.5% (  0.2)              kded : schedule_timeout (process_timeout)
   0.5% (  0.2)     <kernel core> : __netdev_watchdog_up (dev_watchdog)
   0.5% (  0.2)              Xorg : do_setitimer (it_real_fn)
   0.5% (  0.2)   <kernel module> : neigh_table_init_no_netlink
(neigh_periodic_timer) 
0.5% (  0.2)            Thunar :
schedule_timeout (process_timeout) 
0.5% (  0.2)         ssh-agent :
schedule_timeout (process_timeout) 
0.5% (  0.2)         ssh-agent :
do_setitimer (it_real_fn) 
0.2% (  0.1)         klauncher :
schedule_timeout (process_timeout) 
0.2% (  0.1)       xfce4-panel :
schedule_timeout (process_timeout) 
0.2% (  0.1)   xfce4-menu-plug :
schedule_timeout (process_timeout) 
0.2% (  0.1)              cron :
do_nanosleep (hrtimer_wakeup) 
0.2% (  0.1)            pidgin :
sk_reset_timer (tcp_write_timer) 
0.2% (  0.1)     <kernel core> :
init_nonfatal_mce_checker (delayed_work_timer_fn) 

-- 
Amit Walambe
Design Engineer, Arcom Control Systems Ltd.  
http://www.arcom.com 
Tel: +44-(0)1223 411200 ext. 3204 
Direct: +44-(0)1223 403465

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