Messages in this thread | | | Date | Tue, 24 Sep 2013 08:33:40 -0400 | From | Tejun Heo <> | Subject | Re: [PATCH 4/6] x86/mem-hotplug: Support initialize page tables bottom up |
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Hello,
On Tue, Sep 24, 2013 at 06:08:27PM +0800, Zhang Yanfei wrote: > +#ifdef CONFIG_MOVABLE_NODE
You don't need the above ifdef. The compiler will be able to cull the code as long as memblock_bottom_up() is defined as constant expression when !MOVABLE_NODE.
> +/** > + * memory_map_bottom_up - Map [map_start, map_end) bottom up > + * @map_start: start address of the target memory range > + * @map_end: end address of the target memory range > + * > + * This function will setup direct mapping for memory range [map_start, map_end) > + * in a heuristic way. In the beginning, step_size is small. The more memory we > + * map memory in the next loop.
The same comment as before. Now we have two function with the identical comment but behaving differently, which isn't nice.
... > + * If the allocation is in bottom-up direction, we start from the > + * bottom and go to the top: first [kernel_end, end) and then > + * [ISA_END_ADDRESS, kernel_end). Otherwise, we start from the top > + * (end of memory) and go to the bottom. > + * > + * The memblock_find_in_range() gets us a block of RAM in > + * [min_pfn_mapped, max_pfn_mapped) used as new pages for page table. > */ > - memory_map_top_down(ISA_END_ADDRESS, end); > + if (memblock_bottom_up()) { > + unsigned long kernel_end; > + > + kernel_end = round_up(__pa_symbol(_end), PMD_SIZE); > + memory_map_bottom_up(kernel_end, end); > + memory_map_bottom_up(ISA_END_ADDRESS, kernel_end);
Hmm... so, this is kinda weird. We're doing it in two chunks and mapping memory between ISA_END_ADDRESS and kernel_end right on top of ISA_END_ADDRESS? Can't you give enough information to the mapping function so that it can map everything on top of kernel_end in single go?
Thanks.
-- tejun
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