Bug 9893 (HIMEM4G) - When CONFIG_HIMEM4G is set, the kernel only identifies 2GB of the 4GB the bios identifies
Summary: When CONFIG_HIMEM4G is set, the kernel only identifies 2GB of the 4GB the bio...
Status: REJECTED DOCUMENTED
Alias: HIMEM4G
Product: Memory Management
Classification: Unclassified
Component: MTTR (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: Andrew Morton
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2008-02-05 07:43 UTC by Andrew J Barbaccia III
Modified: 2008-09-25 08:02 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.6.24
Subsystem:
Regression: ---
Bisected commit-id:

Attachments
dmesg (34.56 KB, text/plain)
2008-05-03 17:32 UTC, Andrew J Barbaccia III 		Details
/proc/mtrr (199 bytes, application/octet-stream)
2008-05-03 17:32 UTC, Andrew J Barbaccia III 		Details
Add an attachment (proposed patch, testcase, etc.)

Description Andrew J Barbaccia III 2008-02-05 07:43:27 UTC 
Latest working kernel version: None
Earliest failing kernel version: All
Distribution: Ubuntu Hardy
Hardware Environment: 4GB RAM, Intel Core2 6600
Software Environment: 
Problem Description: /proc/meminfo only displays 2GB of mem while it should show the full 4GB. When compiled with CONFIG_HIMEM64G=y, the full 4GB of mem is displayed.

Steps to reproduce: Compile the kernel with CONFIG_HIMEM4G=y on a system with 4GB of ram.
Comment 1 Natalie Protasevich 2008-05-03 17:06:30 UTC 
Can you attach your dmesg and /proc/mtrr please.
Comment 2 Andrew J Barbaccia III 2008-05-03 17:32:16 UTC 
Created attachment 16015 [details]
dmesg
Comment 3 Andrew J Barbaccia III 2008-05-03 17:32:29 UTC 
Created attachment 16016 [details]
/proc/mtrr
Comment 4 Natalie Protasevich 2008-06-01 20:54:37 UTC 
OK, this was with HIGHMEM64 support, how about the same without it for comparison. It would also help to have /proc/meminfo for both cases.
Comment 5 Alan 2008-09-25 08:02:12 UTC 
Your bios is mapping 2GB of your RAM above the 4GB boundary so this is expected behaviour.
Note You need to log in before you can comment on or make changes to this bug.