Re: Top strangeness

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Ok, well I decided to do a little more testing before I dismantled my testbed.
:What I found is that I get the following:
:
:Network load = 15K pps:     System 5% Interrupt 9-12%
:
:Network load = 34Kpps:      System 10% Interrupt 10-14%
:
:(the interrupt number bounces around a bit)
:
:Something doesn't seem right. Generally the load increases are linear for
:this sort of test. The interrupt load seems about the same for what should
:be twice the load. Even if no additional interrupts were generated I can't see
:that the interrupt work could be that similar for double the load.

    This sounds about right, actually.  The EM device is aggregating
    packets and thus the interrupt code becomes more efficient at higher
    loads.  It's also tight enough that it probably fits entirely in the cpu's
    L1 cache.

					-Matt
					Matthew Dillon 
					<dillon@xxxxxxxxxxxxx>