amrd disk performance drop after running under high load

[Boris Samorodov]

On Thu, 18 Oct 2007 15:57:16 -0600 Scott Long wrote:
> Boris Samorodov wrote:

> > Since nobody answered so far, here is my two cents. I'm not an expert
> > here so it's only my imho.
> >
> > On Wed, 17 Oct 2007 22:52:49 +0400 Alexey Popov wrote:
> >
> >> interrupt                          total       rate
> >> irq6: fdc0                             8          0
> >> irq14: ata0                           47          0
> >> irq16: uhci0                  1428187319       1851
> >                                 ^^^^^^^^^^       ^^^^ [1]
> >> irq18: uhci2                    12374352         16
> >> irq23: ehci0                           3          0
> >> irq46: amr0                     11983237         15
> >> irq64: em0                    1427141755       1850
> >                                 ^^^^^^^^^^       ^^^^ [2]
> >> cpu0: timer                   1540896452       1997
> >> cpu1: timer                   1542377798       1999
> >> Total                         5962960971       7730
> >
> > [1] and [2] looks suspicious to me (totals and rate are too close to
> > each other and btw to timers). Let the latter (timers) alone. Do you
> > use any USB device? Can you try to use other network card? That
> > behaviour seems to be an interrupt storm and/or irq collision.

> It's neither.  It's a side effect of a feature that FreeBSD abuses for
> handling interrupts.  Note that amr0 and ehci2 are acting similar.  It's
> mostly harmless, but it does waste CPU cycles.  I wouldn't expect this
> on a recent version of FreeBSD, though, at least not from the e1000
> driver.

I see. Sorry for the noise. So, as I can understand _that_ can't be the
problem (as at subj) the OP is seeing?


WBR
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