Re: Re: big IRQ latencies, was: <no subject>

Re: Re: big IRQ latencies, was: <no subject>

[joerg.beyer]

Matti Aarnio <matti.aarnio@zmailer.org> schrieb am 25.08.02 15:18:07:
> On Sun, Aug 25, 2002 at 02:38:59PM +0200, joerg.beyer@email.de wrote:
> > Zwane Mwaikambo <zwane@linuxpower.ca> schrieb am 25.08.02 14:10:12:
> > > On Sun, 25 Aug 2002 joerg.beyer@email.de wrote:
> > ...
> > > That should fix your slowdown during untarring/disk access, as for your 
> > > NIC problem looks like you might be having a receive FIFO overflow, so 
> > > perhaps the card stops processing incoming packets? I have no clue, 
> > 
> > maybe this helps: outgoing transfer (from the laptop to some
> > other machine) is reasonable fast: I could copy gig's of data
> > away, but not to the machine. I asume sending away makes not
> > so heavy use of IRQ's, right?
> 
> A laptop, you say ?   And network reception is jamming while

yes a laptop.

> there is high disk-write activity ?

nope - no other disk activity except the scp I used to
copy a file over the net. 
 
>   /sbin/hdparam -v /dev/hda
> 
> /dev/hda:
>  multcount    = 16 (on)
>  I/O support  =  1 (32-bit)  <-----  ??
>  unmaskirq    =  1 (on)      <-----  ??
>  using_dma    =  1 (on)      <-----  ??
>  keepsettings =  1 (on)      <-----  ??
>  nowerr       =  0 (off)
>  readonly     =  0 (off)
>  readahead    =  8 (on)
> 

I set the values as you suggested, but it made no difference:

joerg@laptop> scp othermachione:1gig_file /tmp

it take ~ 1/2 minute for 1 gig and gives a lot of errors
on the nic:

eth0      Protokoll:Ethernet  Hardware Adresse 00:07:CA:00:AC:A3  
          inet Adresse:10.0.0.30  Bcast:10.255.255.255  Maske:255.0.0.0
          UP BROADCAST NOTRAILERS RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:875 errors:6440 dropped:263 overruns:6440 frame:0
          TX packets:897 errors:0 dropped:0 overruns:0 carrier:0
          Kollisionen:0 Sendewarteschlangenlänge:100 
          RX bytes:1234333 (1.1 Mb)  TX bytes:79498 (77.6 Kb)
          Interrupt:10 Basisadresse:0xf000 

along with > 300 entries in /var/log/messages like this:

kernel: eth0: Too much work at interrupt, IntrStatus=0x0040

could anybody explain to me, why there is "Too much work at interrupt"?
and what I could do about it?

    Joerg