Re: Interrupt routine usage not shown by top in 8.0

--- On Thu, 3/12/09, Chris Ruiz <chris_at_young-alumni.com> wrote:

> From: Chris Ruiz <chris_at_young-alumni.com>
> Subject: Re: Interrupt routine usage not shown by top in 8.0
> To: current_at_freebsd.org
> Date: Thursday, March 12, 2009, 5:17 PM
> On Mar 12, 2009, at 3:23 PM, Barney Cordoba wrote:
> 
> >
> > I'm fireing 400Kpps at a udp blackhole port.
> I'm getting 6000  
> > interrupts
> > per second on em3:
> >
> > testbox# vmstat -i; sleep 1; vmstat -i
> > interrupt                          total       rate
> > irq1: atkbd0                           1          0
> > irq6: fdc0                             1          0
> > irq17: uhci1+                       2226          9
> > irq18: uhci2 ehci+                     9          0
> > cpu0: timer                       470507       1993
> > irq256: em0                          665          2
> > irq259: em3                      1027684       4354
> > cpu1: timer                       470272       1992
> > cpu3: timer                       470273       1992
> > cpu2: timer                       470273       1992
> > Total                            2911911      12338
> >
> > interrupt                          total       rate
> > irq1: atkbd0                           1          0
> > irq6: fdc0                             1          0
> > irq17: uhci1+                       2226          9
> > irq18: uhci2 ehci+                     9          0
> > cpu0: timer                       472513       1993
> > irq256: em0                          668          2
> > irq259: em3                      1033703       4361
> > cpu1: timer                       472278       1992
> > cpu3: timer                       472279       1992
> > cpu2: timer                       472279       1992
> > Total                            2925957      12345
> >
> >
> > top -SH shows:
> >
> >  PID  STATE  C   TIME    CPU COMMAND
> >   10  CPU3   3   7:32 100.00% idle
> >   10  CPU2   2   7:32 100.00% idle
> >   10  RUN    0   7:31 100.00% idle
> >   10  CPU1   1   7:31 100.00% idle
> >
> > This implies that CPU usage is substantially
> under-reported in general
> > by the system. Note that I've modified
> em_irq_fast() to call
> > em_handle_rxtx() directly rather than scheduling a
> task to illustrate
> > the problem
> >
> > Barney
> 
> The version of top in the base system is known to provide
> incorrect  
> metrics.
> 
> Chris

Does that imply that there exists a version that provides correct
information? 

Barney