Re: [PATCH] mm/mm_init.c: don't initialize page->lru again

[Mike Rapoport <rppt@kernel.org>]

On Sat, Jun 08, 2024 at 12:35:35AM +0000, Wei Yang wrote:
> On Fri, Jun 07, 2024 at 10:33:41AM +0300, Mike Rapoport wrote:
> >On Wed, Jun 05, 2024 at 10:14:36PM +0000, Wei Yang wrote:
> >> After init_reserved_page(), we expect __init_single_page() has done its
> >> work to the page, which already initialize page->lru properly.
> >
> >init_reserved_page only available with CONFIG_DEFERRED_STRUCT_PAGE_INIT
> 
> The common page initialize path is :
> 
> memmap_init
>     memmap_init_zone_range
>         memmap_init_range
> 	    defer_init
> 	    __init_single_page
> 
> If CONFIG_DEFERRED_STRUCT_PAGE_INIT set, we would skip initialization for pages
> after first_init_pfn. So init_reserved_page would initialize page struct
> before __SetPageReserved().
> 
> If CONFIG_DEFERRED_STRUCT_PAGE_INIT not set, page struct is already initialized.
> 
> Is my understanding correct?
 
Yes, and it should be a part of the changelog :)
 
> >> We don't need to do it again.
> >> 
> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> >> ---
> >>  mm/mm_init.c | 3 ---
> >>  1 file changed, 3 deletions(-)
> >> 
> >> diff --git a/mm/mm_init.c b/mm/mm_init.c
> >> index 14133a1cfc7b..30379b0e7729 100644
> >> --- a/mm/mm_init.c
> >> +++ b/mm/mm_init.c
> >> @@ -759,9 +759,6 @@ void __meminit reserve_bootmem_region(phys_addr_t start,
> >>  
> >>  			init_reserved_page(start_pfn, nid);
> >>  
> >> -			/* Avoid false-positive PageTail() */
> >> -			INIT_LIST_HEAD(&page->lru);
> >> -
> >>  			/*
> >>  			 * no need for atomic set_bit because the struct
> >>  			 * page is not visible yet so nobody should
> >> -- 
> >> 2.34.1
> >> 
> >> 
> >
> >-- 
> >Sincerely yours,
> >Mike.
> 
> -- 
> Wei Yang
> Help you, Help me

-- 
Sincerely yours,
Mike.