Messages in this thread | | | Date | Tue, 24 Sep 2013 21:23:48 +0800 | From | Zhang Yanfei <> | Subject | Re: [PATCH 4/6] x86/mem-hotplug: Support initialize page tables bottom up |
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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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