Re: [PATCH] trim memory not covered by WB MTRRs

From: Pim Zandbergen
Date: Wed Jun 27 2007 - 06:45:26 EST


First:
Jesse saved my life by releasing a patch that made my GigaByte Intel G33
based motherboard use all of its 8GB RAM and not be slow as hell.

Then:
GigaByte released a BIOS update that fixed the root of the problem.
I went back from patched vanilla kernel to "official" Fedora kernel.

Now:
Jesse released a new patch and I tried if for fun on 2.6.22-rc6
It looks like the patch is releasing memory rather than trimming it:

Jun 27 12:22:56 corneille kernel: Linux version 2.6.22-rc6 (pim@corneille) (gcc version 4.1.2 20070502 (Red Hat 4.1.2-12)) #1 SMP Wed Jun 27 11:41:29 CEST 2007
Jun 27 12:22:56 corneille kernel: Command line: root=LABEL=/ console=ttyS0,38400
Jun 27 12:22:56 corneille kernel: BIOS-provided physical RAM map:
Jun 27 12:22:56 corneille kernel: BIOS-e820: 0000000000000000 - 000000000009e800 (usable)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 0000000000100000 - 00000000cf5e0000 (usable)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 00000000cf5e0000 - 00000000cf5e3000 (ACPI NVS)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 00000000cf5e3000 - 00000000cf5f0000 (ACPI data)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 00000000cf5f0000 - 00000000cf600000 (reserved)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 00000000d0000000 - 00000000e0000000 (reserved)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved)
Jun 27 12:22:56 corneille kernel: BIOS-e820: 0000000100000000 - 0000000230000000 (usable)
Jun 27 12:22:56 corneille kernel: end_pfn_map = 2293760
Jun 27 12:22:56 corneille kernel: ***************
Jun 27 12:22:56 corneille kernel: **** WARNING: likely BIOS bug
Jun 27 12:22:56 corneille kernel: **** MTRRs don't cover all of memory, trimmed -65536 pages
Jun 27 12:22:56 corneille kernel: ***************

I tried the earlier patch as well and it gives the same result.
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