Messages in this thread |  | | Date | Mon, 16 Jun 2008 16:52:16 +0800 | From | "Dave Young" <> | Subject | Re: [PATCH] kernel parameter vmalloc size fix |
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On Mon, Jun 16, 2008 at 4:08 PM, Dave Young <hidave.darkstar@gmail.com> wrote: > On Mon, Jun 16, 2008 at 4:01 PM, Ingo Molnar <mingo@elte.hu> wrote: >> >> * Dave Young <hidave.darkstar@gmail.com> wrote: >> >>> booting kernel with vmalloc=[any size<=16m] will oops. >>> >>> It's due to the vm area hole. >>> >>> In include/asm-x86/pgtable_32.h: >>> #define VMALLOC_OFFSET (8 * 1024 * 1024) >>> #define VMALLOC_START (((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) \ >>> & ~(VMALLOC_OFFSET - 1)) >>> >>> BUG_ON in arch/x86/mm/init_32.c will be triggered: >>> BUG_ON((unsigned long)high_memory > VMALLOC_START); >>> >>> Fixed by return -EINVAL for invalid parameter >> >> hm. Why dont we instead add the size of the hole to the >> __VMALLOC_RESERVE value instead? There's nothing inherently bad about >> using vmalloc=16m. The VM area hole is really a kernel-internal >> abstraction that should not be visible in the usage of the parameter.
I built with: __VMALLOC_RESERVE = memparse(arg, &arg) + 2 * VMALLOC_OFFSET;
But it doesn't work, still oops at ie. vmalloc=4M (BUT vmalloc=8M is ok) I can't figure out what's wrong with it.
Regards dave
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