Messages in this thread | | | Date | Fri, 15 Sep 2006 14:08:01 -0700 | From | Jeremy Fitzhardinge <> | Subject | How does the handover from boot allocator to real allocator work |
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Hi Ingo,
I'm digging around trying to work out how the handover from the boot-time allocator to the real memory management works.
I'm missing something important though: bootmem.c:free_all_bootmem() seems to end up just putting all low memory on the freelists. How does this not put the kernel text+data pages on the freelists? Also, presumably things allocated in the bootmem allocator remain allocated for the life of the running kernel?
I'm having a problem in my Xen kernel, in which free_init_pages() ends up getting a bad_page() warning because pfn 1024 has the PG_buddy bit set on it, which was unexpected (this page ends up being in the middle of the initdata section). Page 1024 gets PF_buddy set by free_all_bootmem_core(), and it becomes an order 10 page.
I presume this is broken because free_all_bootmem_core() shouldn't be putting the kernel text+data into the freelists, but I don't see how this is prevented in the normal i386 case. I'm guessing it's done by something like reserve_bootmem(), but I don't see such a call which would reserve the kernel itself.
What am I missing?
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