2.4.x high irq contention

2.4.x high irq contention

[Anton Petrusevich]

Hi people,

This is 2.4.21-pre4aa3, but the same applies to 2.4.20-vanilla, and i
think to any 2.4.x. The NIC is RTL-8139(8139too). I would really like to 
know what could be done in this situation. The machine (p3-1GHz) is almost 
unrespobsible. Yes, there are really network card interrupts. So, here it goes.
# readprofile -m /boot/System.map | sort -nr +2 | head -20
  2600 handle_IRQ_event                          23.2143
   268 system_call                                4.7857
   184 fget                                       3.8333
   123 sock_poll                                  2.5625
   421 kfree                                      2.1927
   101 __free_pages                               2.1042
   288 do_softirq                                 2.0000
   326 skb_copy_and_csum_dev                      1.8523
    56 restore_fpu                                1.7500
   232 send_sig_info                              1.6111
   123 poll_freewait                              1.5375
   174 __wake_up                                  1.3594
   695 do_schedule                                1.2776
    19 sockfs_delete_dentry                       1.1875
    70 del_timer                                  1.0938
   592 save_i387                                  1.0278
    17 ret_from_sys_call                          1.0000
   111 skb_release_data                           0.9911
    58 __generic_copy_to_user                     0.9062
   115 do_pollfd                                  0.8984

-- 
Anton Petrusevich

Re: 2.4.x high irq contention

[Stephan von Krawczynski]

I don't know much about your network load, but if you have a lot, then you
should probably throw away the 8139 network card and use tulip or 3com instead.

Regards,
Stephan


On Tue, 22 Apr 2003 10:32:01 +0700
Anton Petrusevich <casus@mail.ru> wrote:

> Hi people,
> 
> This is 2.4.21-pre4aa3, but the same applies to 2.4.20-vanilla, and i
> think to any 2.4.x. The NIC is RTL-8139(8139too). I would really like to 
> know what could be done in this situation. The machine (p3-1GHz) is almost 
> unrespobsible. Yes, there are really network card interrupts. So, here it
> goes.
> # readprofile -m /boot/System.map | sort -nr +2 | head -20
>   2600 handle_IRQ_event                          23.2143
>    268 system_call                                4.7857
>    184 fget                                       3.8333
>    123 sock_poll                                  2.5625
>    421 kfree                                      2.1927
>    101 __free_pages                               2.1042
>    288 do_softirq                                 2.0000
>    326 skb_copy_and_csum_dev                      1.8523
>     56 restore_fpu                                1.7500
>    232 send_sig_info                              1.6111
>    123 poll_freewait                              1.5375
>    174 __wake_up                                  1.3594
>    695 do_schedule                                1.2776
>     19 sockfs_delete_dentry                       1.1875
>     70 del_timer                                  1.0938
>    592 save_i387                                  1.0278
>     17 ret_from_sys_call                          1.0000
>    111 skb_release_data                           0.9911
>     58 __generic_copy_to_user                     0.9062
>    115 do_pollfd                                  0.8984
> 
> -- 
> Anton Petrusevich
> 
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Re: 2.4.x high irq contention

[Alan Cox]

On Maw, 2003-04-22 at 11:40, Stephan von Krawczynski wrote:
> I don't know much about your network load, but if you have a lot, then you
> should probably throw away the 8139 network card and use tulip or 3com instead.

Won't help a lot. If its all IRQ load (eg lots of multicast streaming
audio small frames) then you want an eepro100 or something similar that
has interrupt mitigators.

Re: 2.4.x high irq contention

[Stephan von Krawczynski]

On 22 Apr 2003 14:47:53 +0100
Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

> On Maw, 2003-04-22 at 11:40, Stephan von Krawczynski wrote:
> > I don't know much about your network load, but if you have a lot, then you
> > should probably throw away the 8139 network card and use tulip or 3com
> > instead.
> 
> Won't help a lot. If its all IRQ load (eg lots of multicast streaming
> audio small frames) then you want an eepro100 or something similar that
> has interrupt mitigators.

Well, handwaving about the network load/type ;-)
Could as well be two RTL back-to-back, normal packets but high bandwidth. 
(watch collisions for this case :-)

Regards,
Stephan

2.4.x high irq contention

[Chuck Ebbert]

> This is 2.4.21-pre4aa3, but the same applies to 2.4.20-vanilla, and i
> think to any 2.4.x. The NIC is RTL-8139(8139too). I would really like to 
> know what could be done in this situation.


  Get a real network card. ;)

  I found two used Compaq NC-3121 (Intel e100) for $15 each...



------
 Chuck

Re: 2.4.x high irq contention

[Chuck Ebbert]

>> Won't help a lot. If its all IRQ load (eg lots of multicast streaming
>> audio small frames) then you want an eepro100 or something similar that
>> has interrupt mitigators.
>
> Well, handwaving about the network load/type ;-)
> Could as well be two RTL back-to-back, normal packets but high bandwidth. 
> (watch collisions for this case :-)


  RTL-8139: the hardware equivalent of a bicycle.

  8))
------
 Chuck