[v1,2/2] mm/memory_hotplug: don't use __GFP_HARDWALL when migrating pages via memory offlining

Commit Message

David Hildenbrand Dec. 5, 2024, 8:52 a.m. UTC

We'll migrate pages allocated by other context; respecting the cpuset of
the memory offlining context when allocating a migration target does not
make sense.

Drop the __GFP_HARDWALL by using GFP_KERNEL.

Note that in an ideal world, migration code could figure out the cpuset
of the original context and take that into consideration.

Suggested-by: Vlastimil Babka <[e-mail]>
Signed-off-by: David Hildenbrand <[e-mail]>
---
 mm/memory_hotplug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Oscar Salvador Dec. 9, 2024, 7:48 a.m. UTC | #1

On Thu, Dec 05, 2024 at 09:52:17AM +0100, David Hildenbrand wrote:
> We'll migrate pages allocated by other context; respecting the cpuset of
> the memory offlining context when allocating a migration target does not
> make sense.
> 
> Drop the __GFP_HARDWALL by using GFP_KERNEL.
> 
> Note that in an ideal world, migration code could figure out the cpuset
> of the original context and take that into consideration.
> 
> Suggested-by: Vlastimil Babka <[e-mail]>
> Signed-off-by: David Hildenbrand <[e-mail]>

Acked-by: Oscar Salvador <[e-mail]>

Patch

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 5f497ccf473d..3b6f93962481 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1838,7 +1838,7 @@  static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 		nodemask_t nmask = node_states[N_MEMORY];
 		struct migration_target_control mtc = {
 			.nmask = &nmask,
-			.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
+			.gfp_mask = GFP_KERNEL | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
 			.reason = MR_MEMORY_HOTPLUG,
 		};
 		int ret;