Messages in this thread | | | Date | Thu, 21 Jun 2012 13:17:28 -0700 | From | Tejun Heo <> | Subject | Re: Early boot panic on machine with lots of memory |
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Hello, Yinghai.
On Tue, Jun 19, 2012 at 07:57:45PM -0700, Yinghai Lu wrote: > if it is that case, that change could fix other problem problem too. > --- during the one free reserved.regions could double the array.
Yeah, that sounds much more attractive to me too. Some comments on the patch tho.
> /** > * memblock_double_array - double the size of the memblock regions array > * @type: memblock type of the regions array being doubled > @@ -216,7 +204,7 @@ static int __init_memblock memblock_doub > > /* Calculate new doubled size */ > old_size = type->max * sizeof(struct memblock_region); > - new_size = old_size << 1; > + new_size = PAGE_ALIGN(old_size << 1);
We definintely can use some comments explaining why we want page alignment. It's kinda subtle.
This is a bit confusing here because old_size is the proper size without padding while new_size is page aligned size with possible padding. Maybe discerning {old|new}_alloc_size is clearer? Also, I think adding @new_cnt variable which is calculated together would make the code easier to follow. So, sth like,
/* explain why page aligning is necessary */ old_size = type->max * sizeof(struct memblock_region); old_alloc_size = PAGE_ALIGN(old_size);
new_max = type->max << 1; new_size = new_max * sizeof(struct memblock_region); new_alloc_size = PAGE_ALIGN(new_size);
and use alloc_sizes for alloc/frees and sizes for everything else.
> unsigned long __init free_low_memory_core_early(int nodeid) > { > unsigned long count = 0; > - phys_addr_t start, end; > + phys_addr_t start, end, size; > u64 i; > > - /* free reserved array temporarily so that it's treated as free area */ > - memblock_free_reserved_regions(); > + for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL) > + count += __free_memory_core(start, end); > > - for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL) { > - unsigned long start_pfn = PFN_UP(start); > - unsigned long end_pfn = min_t(unsigned long, > - PFN_DOWN(end), max_low_pfn); > - if (start_pfn < end_pfn) { > - __free_pages_memory(start_pfn, end_pfn); > - count += end_pfn - start_pfn; > - } > - } > + /* free range that is used for reserved array if we allocate it */ > + size = get_allocated_memblock_reserved_regions_info(&start); > + if (size) > + count += __free_memory_core(start, start + size);
I'm afraid this is too early. We don't want the region to be unmapped yet. This should only happen after all memblock usages are finished which I don't think is the case yet.
Thanks.
-- tejun
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