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* [PATCH v2 2/2] mm/mm_init.c: remove reset_node_present_pages()
       [not found] <d92273f6-28be-dc37-3ca5-a9579a75f8c4@redhat.com>
@ 2023-06-07  2:50 ` Haifeng Xu
  2023-06-07 10:33   ` Michal Hocko
  2023-06-07 11:38   ` David Hildenbrand
  0 siblings, 2 replies; 3+ messages in thread
From: Haifeng Xu @ 2023-06-07  2:50 UTC (permalink / raw
  To: david; +Cc: rppt, osalvador, mhocko, akpm, linux-mm, linux-kernel, Haifeng Xu

reset_node_present_pages() only get called in hotadd_init_pgdat(), move
the action that clear present pages to free_area_init_core_hotplug(), so
the helper can be removed.

Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Suggested-by: David Hildenbrand <david@redhat.com>
---
v2:
- declare 'struct zone' within the for loop
- fix comment layout
---
 mm/memory_hotplug.c | 18 ------------------
 mm/mm_init.c        | 15 +++++++++++++--
 2 files changed, 13 insertions(+), 20 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 65e385f34679..ee1c0d9a4d5a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1172,16 +1172,6 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
 	return ret;
 }
 
-static void reset_node_present_pages(pg_data_t *pgdat)
-{
-	struct zone *z;
-
-	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
-		z->present_pages = 0;
-
-	pgdat->node_present_pages = 0;
-}
-
 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
 static pg_data_t __ref *hotadd_init_pgdat(int nid)
 {
@@ -1204,14 +1194,6 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
 	 */
 	build_all_zonelists(pgdat);
 
-	/*
-	 * When memory is hot-added, all the memory is in offline state. So
-	 * clear all zones' present_pages because they will be updated in
-	 * online_pages() and offline_pages().
-	 * TODO: should be in free_area_init_core_hotplug?
-	 */
-	reset_node_present_pages(pgdat);
-
 	return pgdat;
 }
 
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 78e67041ae9f..a02ba9a79b3d 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1507,6 +1507,8 @@ void __ref free_area_init_core_hotplug(struct pglist_data *pgdat)
 	pgdat->kswapd_order = 0;
 	pgdat->kswapd_highest_zoneidx = 0;
 	pgdat->node_start_pfn = 0;
+	pgdat->node_present_pages = 0;
+
 	for_each_online_cpu(cpu) {
 		struct per_cpu_nodestat *p;
 
@@ -1514,8 +1516,17 @@ void __ref free_area_init_core_hotplug(struct pglist_data *pgdat)
 		memset(p, 0, sizeof(*p));
 	}
 
-	for (z = 0; z < MAX_NR_ZONES; z++)
-		zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
+	/*
+	 * When memory is hot-added, all the memory is in offline state. So
+	 * clear all zones' present_pages and managed_pages because they will
+	 * be updated in online_pages() and offline_pages().
+	 */
+	for (z = 0; z < MAX_NR_ZONES; z++) {
+		struct zone *zone = pgdat->node_zones + z;
+
+		zone->present_pages = 0;
+		zone_init_internals(zone, z, nid, 0);
+	}
 }
 #endif
 
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2 2/2] mm/mm_init.c: remove reset_node_present_pages()
  2023-06-07  2:50 ` [PATCH v2 2/2] mm/mm_init.c: remove reset_node_present_pages() Haifeng Xu
@ 2023-06-07 10:33   ` Michal Hocko
  2023-06-07 11:38   ` David Hildenbrand
  1 sibling, 0 replies; 3+ messages in thread
From: Michal Hocko @ 2023-06-07 10:33 UTC (permalink / raw
  To: Haifeng Xu; +Cc: david, rppt, osalvador, akpm, linux-mm, linux-kernel

On Wed 07-06-23 02:50:56, Haifeng Xu wrote:
> reset_node_present_pages() only get called in hotadd_init_pgdat(), move
> the action that clear present pages to free_area_init_core_hotplug(), so
> the helper can be removed.

There is no explanation why moving the action is desirable and/or
needed. I do agree that removing this trivial helper which only has a
single caller. I guess the incentive is an overal simplification but
please spell that out.

> Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
> Suggested-by: David Hildenbrand <david@redhat.com>

The patch itself makes sense
Acked-by: Michal Hocko <mhocko@suse.com>

> ---
> v2:
> - declare 'struct zone' within the for loop
> - fix comment layout
> ---
>  mm/memory_hotplug.c | 18 ------------------
>  mm/mm_init.c        | 15 +++++++++++++--
>  2 files changed, 13 insertions(+), 20 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 65e385f34679..ee1c0d9a4d5a 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1172,16 +1172,6 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
>  	return ret;
>  }
>  
> -static void reset_node_present_pages(pg_data_t *pgdat)
> -{
> -	struct zone *z;
> -
> -	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
> -		z->present_pages = 0;
> -
> -	pgdat->node_present_pages = 0;
> -}
> -
>  /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
>  static pg_data_t __ref *hotadd_init_pgdat(int nid)
>  {
> @@ -1204,14 +1194,6 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
>  	 */
>  	build_all_zonelists(pgdat);
>  
> -	/*
> -	 * When memory is hot-added, all the memory is in offline state. So
> -	 * clear all zones' present_pages because they will be updated in
> -	 * online_pages() and offline_pages().
> -	 * TODO: should be in free_area_init_core_hotplug?
> -	 */
> -	reset_node_present_pages(pgdat);
> -
>  	return pgdat;
>  }
>  
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 78e67041ae9f..a02ba9a79b3d 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -1507,6 +1507,8 @@ void __ref free_area_init_core_hotplug(struct pglist_data *pgdat)
>  	pgdat->kswapd_order = 0;
>  	pgdat->kswapd_highest_zoneidx = 0;
>  	pgdat->node_start_pfn = 0;
> +	pgdat->node_present_pages = 0;
> +
>  	for_each_online_cpu(cpu) {
>  		struct per_cpu_nodestat *p;
>  
> @@ -1514,8 +1516,17 @@ void __ref free_area_init_core_hotplug(struct pglist_data *pgdat)
>  		memset(p, 0, sizeof(*p));
>  	}
>  
> -	for (z = 0; z < MAX_NR_ZONES; z++)
> -		zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
> +	/*
> +	 * When memory is hot-added, all the memory is in offline state. So
> +	 * clear all zones' present_pages and managed_pages because they will
> +	 * be updated in online_pages() and offline_pages().
> +	 */
> +	for (z = 0; z < MAX_NR_ZONES; z++) {
> +		struct zone *zone = pgdat->node_zones + z;
> +
> +		zone->present_pages = 0;
> +		zone_init_internals(zone, z, nid, 0);
> +	}
>  }
>  #endif
>  
> -- 
> 2.25.1

-- 
Michal Hocko
SUSE Labs


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2 2/2] mm/mm_init.c: remove reset_node_present_pages()
  2023-06-07  2:50 ` [PATCH v2 2/2] mm/mm_init.c: remove reset_node_present_pages() Haifeng Xu
  2023-06-07 10:33   ` Michal Hocko
@ 2023-06-07 11:38   ` David Hildenbrand
  1 sibling, 0 replies; 3+ messages in thread
From: David Hildenbrand @ 2023-06-07 11:38 UTC (permalink / raw
  To: Haifeng Xu; +Cc: rppt, osalvador, mhocko, akpm, linux-mm, linux-kernel

On 07.06.23 04:50, Haifeng Xu wrote:
> reset_node_present_pages() only get called in hotadd_init_pgdat(), move
> the action that clear present pages to free_area_init_core_hotplug(), so
> the helper can be removed.
> 
> Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
> Suggested-by: David Hildenbrand <david@redhat.com>
> ---
> v2:
> - declare 'struct zone' within the for loop
> - fix comment layout
> ---
>   mm/memory_hotplug.c | 18 ------------------
>   mm/mm_init.c        | 15 +++++++++++++--
>   2 files changed, 13 insertions(+), 20 deletions(-)

As Michal said, we could be clearer that this simplifies the code (and 
removes a TODO).

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb



^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-06-07 11:39 UTC | newest]

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     [not found] <d92273f6-28be-dc37-3ca5-a9579a75f8c4@redhat.com>
2023-06-07  2:50 ` [PATCH v2 2/2] mm/mm_init.c: remove reset_node_present_pages() Haifeng Xu
2023-06-07 10:33   ` Michal Hocko
2023-06-07 11:38   ` David Hildenbrand

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