Arch Linux

lardon

Member

Registered: 2008-05-31

Posts: 264

Website

MTRR "problems"

Hi all,

I noticed the following message in my kernel's boot log:

mtrr: type mismatch for e0000000,10000000 old: write-back new: write-combining
[drm] MTRR allocation failed.  Graphics performance may suffer.

Since I don't want to cause unneeded suffering, I'm trying to investigate the matter. After some research, I found that some people have success with the "enable_mtrr_cleanup" kernel boot parameter. So I tried adding it, but it didn't change anything, I still have the same error message. I also have the following messages:

mtrr_cleanup: can not find optimal value
please specify mtrr_gran_size/mtrr_chunk_size

So is this a problem? If so, how can I fix it?

Thanks!

Machine details:

00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07)
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:1a.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 02)
00:1a.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 02)
00:1a.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 02)
00:1a.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 02)
00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 (rev 02)
00:1c.4 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 5 (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 92)
00:1f.0 ISA bridge: Intel Corporation ICH9M LPC Interface Controller (rev 02)
00:1f.2 SATA controller: Intel Corporation ICH9M/M-E SATA AHCI Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 02)
09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5756ME Gigabit Ethernet PCI Express
0c:00.0 Network controller: Intel Corporation Wireless WiFi Link 5100

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Ranguvar

Member

Registered: 2008-08-12

Posts: 2,549

Re: MTRR "problems"

Are you using uvesafb?

lardon

Member

Registered: 2008-05-31

Posts: 264

Website

Re: MTRR "problems"

Are you using uvesafb?

I've never heard of it I guess that means I don't use it?

I should probably mention I'm using KMS, though.

Last edited by lardon (2009-09-10 23:07:51)

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Bogart

Member

From: Madrid, Spain

Registered: 2005-06-22

Posts: 272

Re: MTRR "problems"

AFAIK this is a benign warning. I used to have it and it went away with the enable_mtrr_cleanup boot parameter. But it never really affected my performance. Do you suffer from bad performance or you're just worried about the message itself?

There were some bug reports about it in bugs.freedesktop.org, you might want to dig there for some more info.

ozar

Member

From: USA

Registered: 2005-02-18

Posts: 1,686

Re: MTRR "problems"

I went through the mtrr thing for a while about a year or two ago, but it finally cleared itself up with one of the kernel upgrades.

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oz