Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 19 Oct 2007 03:00:52 +0400
From:      Boris Samorodov <bsam@ipt.ru>
To:        Scott Long <scottl@samsco.org>
Cc:        freebsd-hackers@freebsd.org, freebsd-stable@freebsd.org
Subject:   Re: amrd disk performance drop after running under high load
Message-ID:  <32246027@ipt.ru>
In-Reply-To: <4717D6BC.5090206@samsco.org> (Scott Long's message of "Thu\, 18 Oct 2007 15\:57\:16 -0600")
References:  <47137D36.1020305@chistydom.ru> <47140906.2020107@FreeBSD.org> <47146FB4.6040306@chistydom.ru> <47147E49.9020301@FreeBSD.org> <47149E6E.9000500@chistydom.ru> <4715035D.2090802@FreeBSD.org> <4715C297.1020905@chistydom.ru> <4715C5D7.7060806@FreeBSD.org> <47165A01.1030806@chistydom.ru> <07289061@ipt.ru> <4717D6BC.5090206@samsco.org>

next in thread | previous in thread | raw e-mail | index | archive | help
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
-- 
bsam



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?32246027>