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Date:      Thu, 23 Mar 2006 18:50:23 +0100
From:      Paolo Pisati <p.pisati@oltrelinux.com>
To:        FreeBSD_Current <freebsd-current@freebsd.org>
Subject:   Re: interesting(?) data on network interrupt servicing
Message-ID:  <20060323175023.GA1039@tin.it>
In-Reply-To: <200603231112.26646.jhb@freebsd.org>
References:  <20060322122906.A41691@xorpc.icir.org> <200603221545.13769.jhb@freebsd.org> <20060323003228.GA1983@tin.it> <200603231112.26646.jhb@freebsd.org>

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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



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