Bug 42786 - When booting with 32GB ram linux fails to find optimal mtrr when i915 (HD 3000) has 512 MB
Summary: When booting with 32GB ram linux fails to find optimal mtrr when i915 (HD 300...
Status: NEW
Alias: None
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64 (show other bugs)
Hardware: All Linux
: P1 low
Assignee: platform_x86_64@kernel-bugs.osdl.org
URL: https://bugs.launchpad.net/ubuntu/+so...
Keywords:
Depends on:
Blocks:
 
Reported: 2012-02-16 22:04 UTC by Andrew Smith
Modified: 2017-03-06 19:58 UTC (History)
1 user (show)

See Also:
Kernel Version: v3.3-rc3
Subsystem:
Regression: No
Bisected commit-id:

Attachments
DMESG (73.49 KB, text/plain)
2012-02-16 22:05 UTC, Andrew Smith 		Details
DMESG-256 (63.59 KB, text/plain)
2012-02-16 22:05 UTC, Andrew Smith 		Details
cat /proc/mtrr (483 bytes, text/plain)
2012-02-16 22:06 UTC, Andrew Smith 		Details
cat /proc/mtrr (256) (683 bytes, text/plain)
2012-02-16 22:06 UTC, Andrew Smith 		Details
lscvi-vnvn (31.42 KB, text/x-log)
2012-02-16 22:09 UTC, Andrew Smith 		Details
Add an attachment (proposed patch, testcase, etc.)

Description Andrew Smith 2012-02-16 22:04:37 UTC 
I have an ASUS P8Z68-V PRO, W/ BIOS 1101, 32GB of RAM and I am running Ubuntu precise 12.04.

In the BIOS you can set the amount of memory for the "iGPU", the HD3000 GPU built into my i7-2600K.

I just upgraded to 32GB of ram. Before the upgrade, I had this set to 512, had mtrr_spare_reg_nr=1 and everything worked fine. After the upgrade to 32GB of RAM: mtrr_cleanup: can not find optimal value, please specify mtrr_gran_size/mtrr_chunk_size etc. No matter what I set mtrr_spare_reg_nr to I got this error. However, I found that if I turned the amount of memory for the iGPU down to 256, everything works again.

I have found this to be the case even on the latest git pull, v3.3-rc3.

 Other notes, patches, fixes, workarounds: disabling "all memory to be remapped" in bios
Comment 1 Andrew Smith 2012-02-16 22:05:35 UTC 
Created attachment 72414 [details]
DMESG
Comment 2 Andrew Smith 2012-02-16 22:05:54 UTC 
Created attachment 72415 [details]
DMESG-256
Comment 3 Andrew Smith 2012-02-16 22:06:22 UTC 
Created attachment 72416 [details]
cat /proc/mtrr
Comment 4 Andrew Smith 2012-02-16 22:06:52 UTC 
Created attachment 72417 [details]
cat /proc/mtrr (256)
Comment 5 Andrew Smith 2012-02-16 22:09:44 UTC 
Created attachment 72418 [details]
lscvi-vnvn
Comment 6 Andrew Morton 2012-02-16 22:11:27 UTC 
hm, we really shouldn't have a MM/MTRR section here.  Oh well.

I recategorised it as x86_64, thanks.
Comment 7 Szőgyényi Gábor 2017-03-06 19:58:21 UTC 
Please try this bug with latest kernel image.
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