[gentoo-user] dmesg warning about mtrr: type mismatch and allocation failed

["Walter Dnes" <waltdnes@waltdnes.org>]

  I'm running 64-bit Gentoo on an Intel 4-core i3 with an Intel integrated
graphics controller.  An excerpt from dmesg follows, with the video-
related stuff.  Note the two lines that I've split off.  They mention
the mtrr type mismatch and the allocation failure.  Is this a problem
and if so, what do I do about it?

[    0.519939] Linux agpgart interface v0.103
[    0.520016] agpgart-intel 0000:00:00.0: Intel HD Graphics Chipset
[    0.520842] agpgart-intel 0000:00:00.0: detected 131068K stolen memory
[    0.580462] agpgart-intel 0000:00:00.0: AGP aperture is 256M @ 0xd0000000
[    0.580740] input: Power Button as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0C:00/input/input0
[    0.582896] ACPI: Power Button [PWRB]
[    0.582986] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input1
[    0.583063] ACPI: Power Button [PWRF]
[    0.583301] Monitor-Mwait will be used to enter C-1 state
[    0.583314] Monitor-Mwait will be used to enter C-3 state
[    0.583325] Monitor-Mwait will be used to enter C-3 state
[    0.586808] [drm] Initialized drm 1.1.0 20060810
[    0.586877] i915 0000:00:02.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
[    0.586934] i915 0000:00:02.0: setting latency timer to 64

[    0.608643] mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
[    0.608725] [drm] MTRR allocation failed.  Graphics performance may suffer.

[    0.608815] i915 0000:00:02.0: irq 26 for MSI/MSI-X
[    0.608819] [drm] set up 127M of stolen space
[    0.946741] Console: switching to colour frame buffer device 240x75
[    0.952156] fb0: inteldrmfb frame buffer device
[    0.952176] registered panic notifier
[    0.952208] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0

  And here is an excerpt from "lspci -vv"

00:02.0 VGA compatible controller: Intel Corporation Clarkdale
Integrated Graphics Controller (rev 12) (prog-if 00 [VGA controller])
        Subsystem: Micro-Star International Co., Ltd. Device 7636
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin A routed to IRQ 26
        Region 0: Memory at fb800000 (64-bit, non-prefetchable) [size=4M]
        Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M]
        Region 4: I/O ports at cc00 [size=8]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
                Address: fee0f00c  Data: 4161
        Capabilities: [d0] Power Management version 2
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [a4] PCI Advanced Features
                AFCap: TP+ FLR+
                AFCtrl: FLR-
                AFStatus: TP-
        Kernel driver in use: i915

-- 
Walter Dnes <waltdnes@waltdnes.org>