LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - General
User Name
Password
Linux - General This Linux forum is for general Linux questions and discussion.
If it is Linux Related and doesn't seem to fit in any other forum then this is the place.

Notices

Reply
 
Search this Thread
Old 02-12-2006, 08:06 AM   #1
cap_ahab
LQ Newbie
 
Registered: Dec 2005
Posts: 15

Rep: Reputation: 0
LowMem persits, even after deinstalling BadRam


Hi There!

I installed BadRam recently, to block some badram. No I deinstalled it, cleaned the /boot/grub/menu.lst file, and checked if /etc/badram.conf is present. Seems alright. However I do not get rid of it, here is the dmesg output:

BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009e800 (usable)
BIOS-e820: 000000000009e800 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000d0000 - 00000000000d8000 (reserved)
BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000003def0000 (usable)
BIOS-e820: 000000003def0000 - 000000003deff000 (ACPI data)
BIOS-e820: 000000003deff000 - 000000003df00000 (ACPI NVS)
BIOS-e820: 000000003df00000 - 000000003e000000 (usable)
BIOS-e820: 00000000fff00000 - 0000000100000000 (reserved)
Warning only 896MB will be used.
Use a HIGHMEM enabled kernel.
896MB LOWMEM available.

I also installed a customised kernel, and this one does this too. I guess it is somewhere now incorporated, where I cannot see it. Does anyone have an idea how to solve this?
BTW, during installation of the new kernel (make menuconfig), I cannot see an option for using badram configuration.
Thanks you any hints!

AHAB
 
Old 02-13-2006, 03:57 PM   #2
bulliver
Senior Member
 
Registered: Nov 2002
Location: Edmonton AB, Canada
Distribution: Gentoo x86_64; Gentoo PPC; FreeBSD; OS X 10.9.4
Posts: 3,743
Blog Entries: 4

Rep: Reputation: 76
Do you have more than 896MB of RAM? If so you should do as the kernel says and enable HIGHMEM support. This has nothing to do with badRam.

Quote:
BTW, during installation of the new kernel (make menuconfig), I cannot see an option for using badram configuration.
Did you apply the BadRam patch correctly?
 
Old 02-14-2006, 05:51 AM   #3
cap_ahab
LQ Newbie
 
Registered: Dec 2005
Posts: 15

Original Poster
Rep: Reputation: 0
Yeah, I sorted out, or better I have been let to this link:
http://kerneltrap.org/node/2450/7217
which describes the problem with LowMem and HighMem when having 1024MB of RAM.
I could have sworn that I had the same amount of memory already before BadRam installation. I compiled the kernel with HighMem support, now I have the full amount. However In the article they recommend not to enable HighMem on just 1024MB, because the mapping seems to be too intense. Rather, one should be happy, without the 128MB en plus.
Anyway, thanks for your help.

Ahab
 
Old 02-14-2006, 06:06 AM   #4
bulliver
Senior Member
 
Registered: Nov 2002
Location: Edmonton AB, Canada
Distribution: Gentoo x86_64; Gentoo PPC; FreeBSD; OS X 10.9.4
Posts: 3,743
Blog Entries: 4

Rep: Reputation: 76
Quote:
It is advised to not enable CONFIG_HIGHMEM in the kernel to utilize the extra 128 MB you get for your 1 GB RAM system. I/O Devices cannot directly address high memory from PCI space, so bounce buffers have to be used. Plus the virtual memory management and paging costs come with extra mappings. For details on bounce buffers, refer to Mel Gorman's documentation (link below).
That is very interesting, and is something I would never have considered. Good thing I have 1.5G
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Badram output from memtest86 seems wrong jshall755 Linux - Hardware 0 11-05-2005 03:50 PM
Memtest86 and badram mullog Linux - Software 7 05-27-2004 02:04 PM
badram the 2nd. mritch Linux - Hardware 3 05-27-2004 12:02 PM
design of badram patterns? mritch Linux - Hardware 0 05-22-2004 03:10 AM
BadRAM for 2.4.19 Obi Perrin Linux - Software 0 02-14-2003 10:52 AM


All times are GMT -5. The time now is 06:55 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration