Re: [Xen-devel] [RFC XEN PATCH 01/16] x86_64/mm: explicitly specify the location to place the frame table

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 12.12.16 at 03:27, <haozhong.zhang@xxxxxxxxx> wrote:
> On 12/09/16 16:35 -0500, Konrad Rzeszutek Wilk wrote:
>>On Mon, Oct 10, 2016 at 08:32:20AM +0800, Haozhong Zhang wrote:
>>> @@ -1413,7 +1414,7 @@ int memory_add(unsigned long spfn, unsigned long 
>>> epfn, unsigned int pxm)
>>>      info.epfn = epfn;
>>>      info.cur = spfn;
>>>
>>> -    ret = extend_frame_table(&info);
>>> +    ret = extend_frame_table(&info, &info);
>>
>>is equivalant to 'info' so I am not sure I understand the purpose
>>behind this patch?
>>
> 
> Yes, they are identical for the ordinary RAM here, and the frame table
> is allocated at the begin of the hot-added RAM. For NVDIMM, the
> hypervisor does not know which part is used for data, so the second
> parameter 'alloc_info' is used to indicate which part can be used for
> the frame table, and might be different from 'info'.

In which case you want to add a comment ahead of that function
clarifying the difference (an perhaps pointing out that the two
may be identical).

Also the commit message should be adjusted a little - this is only
preparation for pmem support, so the wording should reflect that.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel