Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 12 Mar 2013 19:57:30 +0200
From:      Konstantin Belousov <kostikbel@gmail.com>
To:        Max Brazhnikov <makc@freebsd.org>
Cc:        Kevin Oberman <rkoberman@gmail.com>, freebsd-x11@freebsd.org, freebsd-usb@freebsd.org
Subject:   Re: high system load when using i915kms
Message-ID:  <20130312175730.GP3794@kib.kiev.ua>
In-Reply-To: <1974063.Ti2gy7L6k6@mercury.ph.man.ac.uk>
References:  <2460779.xZBtdeG4eu@mercury.ph.man.ac.uk> <1382092.A6MSmtKV3F@mercury.ph.man.ac.uk> <CAN6yY1u%2BSi3YebRpkimTNda0CvWdZoYM5LrVT_VwySQaE1w0OA@mail.gmail.com> <1974063.Ti2gy7L6k6@mercury.ph.man.ac.uk>

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

--jvwPghPpVanPi35O
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Tue, Mar 12, 2013 at 04:53:25PM +0000, Max Brazhnikov wrote:
> On Fri, 08 Mar 2013 11:38:13 -0800 Kevin Oberman wrote:
> > On Fri, Mar 8, 2013 at 10:03 AM, Max Brazhnikov <makc@freebsd.org> wrot=
e:
> > >   PID USERNAME     THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU
> > > COMMAND
> > >    11 root           2 155 ki31     0K    32K RUN     1   4:16 120.35=
%=20
> idle
> > >    12 root          18 -84    -     0K   288K WAIT    0   0:57 76.34%=
 intr
> > >
> > > I've got this after second boot today, although I couldn't reproduce =
it
> > > yesterday even after ten attempts. But sometimes it's quite nasty and=
 I
> > > have
> > > to reboot the system several times to get rid of it.
> > >
> > > Max
> > >
> >=20
> > So the issue is that that the interrupts from one or another of the USB
> > devices has exploded from near zero to around 40K when the kernel modul=
e is
> > loaded?
>=20
> Exactly.
>=20
> > A couple of possibly irrelevant questions. Do you normally manually load
> > the module? I did not research the issue, but when I manually load the
> > module I was seeing things just grind to a halt. If I started Gnome, the
> > module was loaded automatically by X, and things worked.
>=20
> No I don't usually load it manually, I was just wondering what causes the=
=20
> interrupt storm.
>=20
> > Why loading the Intel KMS module would cause a massive increase in
> > interrupts on a USB interface completely baffles me, but I suspect some
> > sort of race is going on when the module is pre-loaded.
>=20
> It happens if I allow X to load the module also, the problem is not due t=
o=20
> pre-loading.

As I said earlier, change in the userspace cannot change the interrupt
routing. What could happen (with very low probability) is that some
kind of display interrupt get aliased to the non-msi one. Since it is
unacknowledged, it causes the storm on the legacy irq line. But I never
saw this on G[M]4*.

Just as the blind shot, try to set hw.drm.msi=3D0 in the loader.conf
or using the kenv, before the i915kms module is loaded.

--jvwPghPpVanPi35O
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (FreeBSD)
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=970A
-----END PGP SIGNATURE-----

--jvwPghPpVanPi35O--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130312175730.GP3794>