On 09/24/2013 08:33 PM, Tejun Heo wrote:
> 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.
yeah, will remove the #if. thanks.
>
>> +/**
>> + * 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.
OK, will change them.
>
> ...
>> + * 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?
You mean we should call memory_map_bottom_up like this:
memory_map_bottom_up(ISA_END_ADDRESS, end)
right?
>
> Thanks.
>
--
Thanks.
Zhang Yanfei
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