Re: interesting(?) data on network interrupt servicing

From: Paolo Pisati <p.pisati_at_oltrelinux.com> Date: Thu, 23 Mar 2006 18:50:23 +0100 · This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:54 UTC

On Thu, Mar 23, 2006 at 11:12:24AM -0500, John Baldwin wrote:
> You probably want preemption on to minimize latency.  

i'm doing preemption now...

> If this is a
> UP machine, you should turn SMP off.  It might be interesting to
> compare using 7.x without APIC as well, since you are not using
> APIC on 4.x.

ok, and what do we expect from it?
besides interrupt masking/eoi, what are the other areas influenced
by apic<->8259 switch?   
moreover, should i profile the asm part too?

       APIC                    8259
	|                       |
	|                       |
     ISR_VEC()                INTR()         
	|                       |
        |                       |             we don't take any measure
========================================== <= above this threshold...
 lapic_handle_intr()    atpic_handle_intr()
        \                    / 
         \                  /
	intr_execute_handlers()
                  |
		  |
		  .
		  .
		  .

--    

Paolo

"le influenze esterne sono troppe, il mondo reale non e' mica 
quello fatato dei komunisti :-p" - Anonymous Lumbard