Re: Out of mtrrs

From: Bill Davidsen
Date: Fri Aug 29 2008 - 23:02:19 EST


J.A. Magallón wrote:
Hi all...

I'm using the xorg intel driver, and drm/X report it has no free mtrrs
in kernel to set up:

one:~# cat /proc/mtrr
reg00: base=0xfffe0000 (4095MB), size= 128KB: write-protect, count=1
reg01: base=0xfffc0000 (4095MB), size= 128KB: uncachable, count=1
reg02: base=0x00000000 ( 0MB), size= 256MB: write-back, count=1
reg03: base=0x10000000 ( 256MB), size= 256MB: write-back, count=1
reg04: base=0x1f800000 ( 504MB), size= 8MB: uncachable, count=1
reg05: base=0x1f600000 ( 502MB), size= 2MB: uncachable, count=1
reg06: base=0x1f500000 ( 501MB), size= 1MB: uncachable, count=1
reg07: base=0x00000000 ( 0MB), size= 128KB: uncachable, count=1

dmesg:

[drm] Initialized i915 1.6.0 20060119 on minor 0
mtrr: no more MTRRs available

one:/var/log# grep Linear x.log
(--) intel(0): Linear framebuffer at 0x20000000

I think X tries to get a mtrr at 0x20000000, but kernel has no free one
to offer.

Does this have any solution ?

I don't, but there have been a LOT of mtrr issues recently. I see that there were patches to -rc5 in that area. Many of my systems have RAM they can't use, even in 32bit PAE mode, and I just have the feeling that there is room for improvement here. For various reasons I would rather run 32 bit on some machines, and to have 3.2GB RAM used in a 8 or 16GB machine seems undesirable at the least, and with PAE and at least three unused mtrr I assume that the problem is soluable, just not today. :-(

I will try a 2.6.27-rc5 build late next week, I have another box to build.

TIA

(Oh, this is 2.6.26.3, intel driver 2.4.2)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)

--
J.A. Magallon <jamagallon()ono!com> \ Software is like sex:
\ It's better when it's free
Mandriva Linux release 2009.0 (Cooker) for i586
Linux 2.6.25-jam13 (gcc 4.3.1 20080515 (GCC) #1 SMP





--
Bill Davidsen <davidsen@xxxxxxx>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot

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