Re: [PATCH v2 02/17] xen/arm: implement helpers to get and update NUMA status

[Jan Beulich <jbeulich@xxxxxxxx>]

On 12.01.2023 07:22, Wei Chen wrote:
>> -----Original Message-----
>> From: Jan Beulich <jbeulich@xxxxxxxx>
>> Sent: 2023年1月11日 0:38
>>
>> On 10.01.2023 09:49, Wei Chen wrote:
>>> --- a/xen/arch/arm/include/asm/numa.h
>>> +++ b/xen/arch/arm/include/asm/numa.h
>>> @@ -22,6 +22,12 @@ typedef u8 nodeid_t;
>>>   */
>>>  #define NR_NODE_MEMBLKS NR_MEM_BANKS
>>>
>>> +enum dt_numa_status {
>>> +    DT_NUMA_INIT,
>>
>> I don't see any use of this. I also think the name isn't good, as INIT
>> can be taken for "initializer" as well as "initialized". Suggesting an
>> alternative would require knowing what the future plans with this are;
>> right now ...
>>
> 
> static enum dt_numa_status __read_mostly device_tree_numa;

There's no DT_NUMA_INIT here. You _imply_ it having a value of zero.

> We use DT_NUMA_INIT to indicate device_tree_numa is in a default value
> (System's initial value, hasn't done initialization). Maybe rename it
> To DT_NUMA_UNINIT be better?

Perhaps, yes.

>>> --- a/xen/arch/x86/include/asm/numa.h
>>> +++ b/xen/arch/x86/include/asm/numa.h
>>> @@ -12,7 +12,6 @@ extern unsigned int numa_node_to_arch_nid(nodeid_t n);
>>>
>>>  #define ZONE_ALIGN (1UL << (MAX_ORDER+PAGE_SHIFT))
>>>
>>> -extern bool numa_disabled(void);
>>>  extern nodeid_t setup_node(unsigned int pxm);
>>>  extern void srat_detect_node(int cpu);
>>>
>>> --- a/xen/include/xen/numa.h
>>> +++ b/xen/include/xen/numa.h
>>> @@ -55,6 +55,7 @@ extern void numa_init_array(void);
>>>  extern void numa_set_node(unsigned int cpu, nodeid_t node);
>>>  extern void numa_initmem_init(unsigned long start_pfn, unsigned long
>> end_pfn);
>>>  extern void numa_fw_bad(void);
>>> +extern bool numa_disabled(void);
>>>
>>>  extern int arch_numa_setup(const char *opt);
>>>  extern bool arch_numa_unavailable(void);
>>
>> How is this movement of a declaration related to the subject of the patch?
>>
> 
> Can I add some messages in commit log to say something like "As we have
> Implemented numa_disabled for Arm, so we move numa_disabled to common header"?

See your own patch 3, where you have a similar statement (albeit you mean
"declaration" there, not "definition"). However, right now numa_disabled()
is a #define on Arm, so the declaration becoming common isn't really
warranted. In fact it'll get in the way of converting function-like macros
to inline functions for Misra.

Jan