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On Sunday 02 April 2006 02:04, kashani wrote: |
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> I've made my problem go away, but I'm a bit curious about why it was |
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> happening. |
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> |
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> I've got nine or so Dell 1850's with 2 x 2GB chips. When I compile |
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> gentoo-source 2.6.15-r1 (and 2.6.14-r5) with support for 4GB I see only |
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> 3GB. 1GB lowmem and 2GB highmem. |
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> |
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> ws04 ~ # cat /proc/meminfo |
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> MemTotal: 3107408 kB |
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> MemFree: 1731660 kB |
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> Buffers: 219720 kB |
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> Cached: 937980 kB |
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> SwapCached: 0 kB |
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> Active: 455100 kB |
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> Inactive: 717924 kB |
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> HighTotal: 2227968 kB |
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> HighFree: 1271588 kB |
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> |
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> When I recompile on the same hardware with support for 64GB RAM I see |
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> the full 4GB in the usual 1GB/3GB split. |
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> |
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> nms02 ~ # cat /proc/meminfo |
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> MemTotal: 4147776 kB |
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> MemFree: 3762712 kB |
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> Buffers: 151404 kB |
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> Cached: 45116 kB |
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> SwapCached: 0 kB |
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> Active: 56724 kB |
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> Inactive: 145000 kB |
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> HighTotal: 3276544 kB |
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> HighFree: 3222936 kB |
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> |
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> However on my HP DL360 with 4 x 1GB RAM I see the 4GB, though it's a bit |
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> smaller, with 4GB enabled in the kernel. Same kernel version as the Dell's. |
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> |
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> ramin@azul ~ $ cat /proc/meminfo |
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> MemTotal: 3977744 kB |
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> MemFree: 116792 kB |
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> Buffers: 296108 kB |
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> Cached: 3157952 kB |
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> SwapCached: 0 kB |
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> Active: 2725152 kB |
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> Inactive: 782956 kB |
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> HighTotal: 3096552 kB |
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> HighFree: 8680 kB |
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> |
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> I've been Googling around for an explantion, but am not really sure what |
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> I'm looking for. I'd assume that I might lose a few hundred MB if the 2 |
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> x 2GB chips are slightly bigger than the 4GB limit rather than the full |
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> 1GB that seems to disappear. I'm guessing some wacky motherboard |
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> interleaving thing where highmem ends up being one chip and the lowmem |
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> the 896MB on the other chip. |
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> |
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> Anyone have a decent theory on this with a nice link? |
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> |
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> kashani |
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Enabling 4GB support instead of 1 will allow < 4GB of ram, _not_ <=4GB. |
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To be sure you can use all of it you have to select 64GB at the kernel. |
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|
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The reason it does work for your DL360 is because the bios works around the |
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problem for you. |
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|
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-- |
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Rick van Hattem Rick.van.Hattem(at)Fawo.nl |
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