On 2022-08-24 8:09 UTC, mhocko@xxxxxxxx wrote:
>On Wed 24-08-22 14:50:58, lizhe.67@xxxxxxxxxxxxx wrote:
>[...]
>> diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
>> index fabb2e1e087f..3e081cf8a1ec 100644
>> --- a/include/linux/page_ext.h
>> +++ b/include/linux/page_ext.h
>> @@ -38,19 +38,22 @@ struct page_ext {
>>
>> extern unsigned long page_ext_size;
>> extern void pgdat_page_ext_init(struct pglist_data *pgdat);
>> +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
>> +extern bool early_page_ext_enable(void);
>> +#endif
>>
>> #ifdef CONFIG_SPARSEMEM
>> static inline void page_ext_init_flatmem(void)
>> {
>> }
>> -extern void page_ext_init(void);
>> +extern void page_ext_init(bool early);
>> static inline void page_ext_init_flatmem_late(void)
>> {
>> }
>> #else
>> extern void page_ext_init_flatmem(void);
>> extern void page_ext_init_flatmem_late(void);
>> -static inline void page_ext_init(void)
>> +static inline void page_ext_init(bool early)
>> {
>> }
>> #endif
>
>Why do you need to make it CONFIG_DEFERRED_STRUCT_PAGE_INIT
>dependant?
Yes it is unnecessary. Thanks!
>[...]
>> diff --git a/init/main.c b/init/main.c
>> index 91642a4e69be..3760c0326525 100644
>> --- a/init/main.c
>> +++ b/init/main.c
>> @@ -849,6 +849,8 @@ static void __init mm_init(void)
>> pgtable_init();
>> debug_objects_mem_init();
>> vmalloc_init();
>> + /* Should be run after vmap initialization */
>> + page_ext_init(true);
>
>you can just
> if (early_page_ext)
> page_ext_init();
>
>> /* Should be run before the first non-init thread is created */
>> init_espfix_bsp();
>> /* Should be run after espfix64 is set up. */
>> @@ -1606,7 +1608,7 @@ static noinline void __init kernel_init_freeable(void)
>> padata_init();
>> page_alloc_init_late();
>> /* Initialize page ext after all struct pages are initialized. */
>> - page_ext_init();
>> + page_ext_init(false);
>
> if (!early_page_ext)
> page_ext_init();
I think we can use an inline function instead of 'early_page_ext' here. The
reason is that if CONFIG_PAGE_EXTENSION=n, 'early_page_ext' is undefined.
Thought we can #define early_page_ext as false, it is ugly.
>>
>> do_basic_setup();
>>
>
>and without the ifdefery it all becomes much more simple.
Yes it becomes much more simple. Thanks for all your advices! I will take your
advices and send a v3 patch.
