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graphicsMan
Tux's lil' helper
Joined: 23 Jan 2004
Posts: 87
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 Posted: Fri Oct 05, 2007 6:07 pm Post subject: Top shows less memory than should be available |
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Hi all -
I am having a bit of confusion about how much memory should show up as available for my applications. I have three identical nodes, and I have three different amounts of available RAM.
machine 0 shows 4046452k total
machine 1 shows 3794504k total
machine 2 shows 3800476k total
I think this may have something to do with kernel version:
0: 2.6.22-gentoo-r6
1: 2.6.21-gentoo-r3
2: 2.6.22-gentoo-r8
Are there any kernel options that could relate to this memory difference?
Thanks! |
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gerard27
Advocate
Joined: 04 Jan 2004
Posts: 2377
Location: Netherlands
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| Posted: Fri Oct 05, 2007 7:16 pm Post subject: |
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Hi graphicsMan,
Do you have 4GB of RAM?
If so set your .config to
I had a similar problem and this solved it.
Gerard.
_________________
To install Gentoo I use sysrescuecd.Based on Gentoo,has firefox to browse Gentoo docs and mc to browse (and edit) files.
The same disk can be used for 32 and 64 bit installs.
You can follow the Handbook verbatim.
http://www.sysresccd.org/Download |
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graphicsMan
Tux's lil' helper
Joined: 23 Jan 2004
Posts: 87
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| Posted: Fri Oct 05, 2007 7:43 pm Post subject: |
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I should have perhaps given a bit more info. These machines are running AMD64, and I think the HIGHMEM option is removed for this configuration. I added it manually, but it made no difference.
Thanks for the suggestion though. |
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eccerr0r
Watchman
Joined: 01 Jul 2004
Posts: 9920
Location: almost Mile High in the USA
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| Posted: Sat Oct 06, 2007 4:20 am Post subject: |
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if they're identical machines, why don't you just use the same kernel for all three machines?
Can you just diff the .config files?
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
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graphicsMan
Tux's lil' helper
Joined: 23 Jan 2004
Posts: 87
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| Posted: Sat Oct 06, 2007 8:16 pm Post subject: |
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| eccerr0r wrote: | if they're identical machines, why don't you just use the same kernel for all three machines?
Can you just diff the .config files? |
Probably a good short term solution. I'm just wondering why this is happening... if I upgrade my kernel again, am I going to end up with less memory? Probably so.
If I diff the .config files I get this:
| Code: |
3,4c3,4
< # Linux kernel version: 2.6.22-gentoo-r8
< # Thu Oct 4 22:18:22 2007
---
> # Linux kernel version: 2.6.22-gentoo-r6
> # Thu Sep 13 01:00:57 2007
76a77
> CONFIG_TIMERFD=y
168,170d168
<
< CONFIG_HIGHMEM=64G
<
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Thanks again. |
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zeek
Guru
Joined: 16 Nov 2002
Posts: 480
Location: Bantayan Island
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| Posted: Mon Oct 08, 2007 4:57 am Post subject: |
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| Check that the BIOS settings are all the same. Memory hole, AGP aperture, USB booting, on-board video, etc. |
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graphicsMan
Tux's lil' helper
Joined: 23 Jan 2004
Posts: 87
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| Posted: Mon Oct 08, 2007 9:51 pm Post subject: |
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Well, looking into the BIOS, I was reminded that these machines aren't 100% identical... the processors in the first machine (4096 MB) are Opteron 2216, and the processors in the other two machines are Opteron 8216.
The other useful bit of info that I learned whilst digging around in the BIOS is that the BIOS reports the same amounts of RAM as the kernel does. So it is definitely something at the BIOS level that is causing my memory differences. It is probably related to the fact that I'm running 2216s and 8216s.
Can anyone confirm this? Is there a way around this happening?
Thanks!
[edit]
Though, it IS interesting that by compiling a different kernel I changed the amount of RAM. Can compiling and installing a new kernel affect how much RAM is seen by the BIOS?
[/edit] |
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