Messages in this thread | | | Date | Sat, 16 Aug 2014 22:36:41 +0800 | From | Xishi Qiu <> | Subject | Re: [PATCH] mem-hotplug: let memblock skip the hotpluggable memory regions in __next_mem_range() |
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On 2014/8/16 21:04, Tejun Heo wrote:
> On Mon, Aug 11, 2014 at 09:31:22PM +0800, Xishi Qiu wrote: >> Let memblock skip the hotpluggable memory regions in __next_mem_range(), >> it is used to to prevent memblock from allocating hotpluggable memory >> for the kernel at early time. The code is the same as __next_mem_range_rev(). >> >> Clear hotpluggable flag before releasing free pages to the buddy allocator. > > Please try to explain "why" in addition to "what". Why do we need to > clear hotpluggable flag in free_low_memory_core_early() in addition to > numa_clear_node_hotplug() in x86 numa.c? Does this make x86 code > redundant? If not, why? >
Hi Tejun,
numa_clear_node_hotplug()? There is only numa_clear_kernel_node_hotplug().
If we don't clear hotpluggable flag in free_low_memory_core_early(), the memory which marked hotpluggable flag will not free to buddy allocator. Because __next_mem_range() will skip them.
free_low_memory_core_early for_each_free_mem_range for_each_mem_range __next_mem_range
Thanks, Xishi Qiu
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