* [PATCH] mm/mm_init.c: don't initialize page->lru again
@ 2024-06-05 22:14 Wei Yang
2024-06-07 7:33 ` Mike Rapoport
0 siblings, 1 reply; 4+ messages in thread
From: Wei Yang @ 2024-06-05 22:14 UTC (permalink / raw)
To: rppt, akpm; +Cc: linux-mm, Wei Yang
After init_reserved_page(), we expect __init_single_page() has done its
work to the page, which already initialize page->lru properly.
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
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/mm_init.c: don't initialize page->lru again
2024-06-05 22:14 [PATCH] mm/mm_init.c: don't initialize page->lru again Wei Yang
@ 2024-06-07 7:33 ` Mike Rapoport
2024-06-08 0:35 ` Wei Yang
0 siblings, 1 reply; 4+ messages in thread
From: Mike Rapoport @ 2024-06-07 7:33 UTC (permalink / raw)
To: Wei Yang; +Cc: akpm, linux-mm
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
> 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.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/mm_init.c: don't initialize page->lru again
2024-06-07 7:33 ` Mike Rapoport
@ 2024-06-08 0:35 ` Wei Yang
2024-06-08 7:56 ` Mike Rapoport
0 siblings, 1 reply; 4+ messages in thread
From: Wei Yang @ 2024-06-08 0:35 UTC (permalink / raw)
To: Mike Rapoport; +Cc: Wei Yang, akpm, linux-mm
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?
>
>> 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
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/mm_init.c: don't initialize page->lru again
2024-06-08 0:35 ` Wei Yang
@ 2024-06-08 7:56 ` Mike Rapoport
0 siblings, 0 replies; 4+ messages in thread
From: Mike Rapoport @ 2024-06-08 7:56 UTC (permalink / raw)
To: Wei Yang; +Cc: akpm, linux-mm
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.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-06-08 7:58 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2024-06-05 22:14 [PATCH] mm/mm_init.c: don't initialize page->lru again Wei Yang
2024-06-07 7:33 ` Mike Rapoport
2024-06-08 0:35 ` Wei Yang
2024-06-08 7:56 ` Mike Rapoport
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