Messages in this thread | | | Date | Mon, 18 Jan 1999 23:58:23 +0300 (MSK) | From | Alexey Vyskubov <> | Subject | Re: [PATCH] New: AMD K6 write allocate |
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Hello!
On 18-Jan-99 Chuck Lever wrote: > > i've installed your k6-patch on a 2.2.0-pre7-ac6 kernel, running on a > 233Mhz AMD-K6 model 6 with 64M (Via VP3 chipset, Award 4.51PG BIOS). > > here's dmesg output: > > Memory: 62684k/65528k available (1384k kernel code, 412k reserved, 988k > data, 60k init) > CPU: AMD AMD-K6tm w/ multimedia extensions stepping 02 > AMD K6 processor, model 6 found. > Checking write allocate state... Write allocate is enabled for 64 > MB of memory > Trying to enable write alocate for 63 MB of memory > Failed!!! > Write allocate is enabled for 60 MB of memory > Checking 386/387 coupling... OK, FPU using exception 16 error > reporting. > Checking 'hlt' instruction... OK. > > apparently the BIOS automatically enables write allocate. however, is > it > correct to reset then re-enable it if the BIOS has already set it up?
Well, looks like I know where is the problem. You have 64 MB of RAM, and shadow RAM is enabled in BIOS setup. So Linux kernel sees just 65528k of memory (which is < 64Mb). When my patch tris to determine memory size in Mb, it gets 63. Because write allocate is enabled for 64 != 63 Mb memory, it tries to re-enable write allocate. Write allocate can be enabled only in 4Mb chunks, so it can enable write allocate only for 60Mb of memory.
I can fix this, but I have two options:
(1) Do not re-enable write allocate if it's already enabled for memory size >= memory, available for kernel (= now) - maybe with the warning
(2) Try to determine physical memory size and re-enable write allocate if and only if it's not enabled for this memory size - maybe with warning about shadow memory.
What to do?
P.S. Turning shadow memory off probably will fix the problem. (Write allocate should not be re-enabled int his case. You'll see just first message: "Write allocate is enabled for 64 MB of memory".) Could you try this for me, please?
-- With best wishes, Alexey Vyskubov. This is a message. Or something silly like that.
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