Messages in this thread | | | Date | Fri, 19 Feb 2010 17:21:22 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: Kernel panic due to page migration accessing memory holes |
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On Fri, 19 Feb 2010 15:10:12 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> 1. re-implement pfn_valid() which returns correct value. > maybe not difficult. but please take care of defining CONFIG_HOLES_IN_.... > etc. > > 2. use DISCONTIGMEM and treat each bank and NUMA node. > There will be no waste for memmap. But other complication of CONFIG_NUMA. > > 3. use SPARSEMEM. > You have even 2 choisce here. > a - Set your MAX_ORDER and SECTION_SIZE to be proper value. > b - waste some amount of memory for memmap on the edge of section. > (and don't free memmap for the edge.) >
I read ARM's code briefly. In 2.6.32, ...I think (1) is implemented. As ==
#ifndef CONFIG_SPARSEMEM int pfn_valid(unsigned long pfn) { struct meminfo *mi = &meminfo; unsigned int left = 0, right = mi->nr_banks;
do { unsigned int mid = (right + left) / 2; struct membank *bank = &mi->bank[mid];
if (pfn < bank_pfn_start(bank)) right = mid; else if (pfn >= bank_pfn_end(bank)) left = mid + 1; else return 1; } while (left < right); return 0; } EXPORT_SYMBOL(pfn_valid); == So, what you should do is upgrade to 2.6.32 or backport this one.
See this.
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b7cfda9fc3d7aa60cffab5367f2a72a4a70060cd
Thanks, -Kame
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