[RFC PATCH 1/3] mm: record the migration reason for struct migration_target_control

[Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>]

To support different hugetlb allocation strategies during hugetlb migration
based on various migration reasons, recording the migration reason for the
migration_target_control structure as a preparation.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
 mm/gup.c            | 1 +
 mm/internal.h       | 1 +
 mm/memory-failure.c | 1 +
 mm/memory_hotplug.c | 1 +
 mm/mempolicy.c      | 1 +
 mm/migrate.c        | 1 +
 mm/page_alloc.c     | 1 +
 mm/vmscan.c         | 3 ++-
 8 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/mm/gup.c b/mm/gup.c
index df83182ec72d..959a1a05b059 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2132,6 +2132,7 @@ static int migrate_longterm_unpinnable_pages(
 		struct migration_target_control mtc = {
 			.nid = NUMA_NO_NODE,
 			.gfp_mask = GFP_USER | __GFP_NOWARN,
+			.reason = MR_LONGTERM_PIN,
 		};
 
 		if (migrate_pages(movable_page_list, alloc_migration_target,
diff --git a/mm/internal.h b/mm/internal.h
index 93e229112045..7677ee4d8e12 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -958,6 +958,7 @@ struct migration_target_control {
 	int nid;		/* preferred node id */
 	nodemask_t *nmask;
 	gfp_t gfp_mask;
+	enum migrate_reason reason;
 };
 
 /*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 9349948f1abf..780bb2aee0af 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2666,6 +2666,7 @@ static int soft_offline_in_use_page(struct page *page)
 	struct migration_target_control mtc = {
 		.nid = NUMA_NO_NODE,
 		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
+		.reason = MR_MEMORY_FAILURE,
 	};
 
 	if (!huge && folio_test_large(folio)) {
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a444e2d7dd2b..b79ba36e09e0 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1841,6 +1841,7 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 		struct migration_target_control mtc = {
 			.nmask = &nmask,
 			.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
+			.reason = MR_MEMORY_HOTPLUG,
 		};
 		int ret;
 
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index f60b4c99f130..98ceb12e0e17 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1070,6 +1070,7 @@ static long migrate_to_node(struct mm_struct *mm, int source, int dest,
 	struct migration_target_control mtc = {
 		.nid = dest,
 		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
+		.reason = MR_SYSCALL,
 	};
 
 	nodes_clear(nmask);
diff --git a/mm/migrate.c b/mm/migrate.c
index 73a052a382f1..bde63010a3cf 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2060,6 +2060,7 @@ static int do_move_pages_to_node(struct list_head *pagelist, int node)
 	struct migration_target_control mtc = {
 		.nid = node,
 		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
+		.reason = MR_SYSCALL,
 	};
 
 	err = migrate_pages(pagelist, alloc_migration_target, NULL,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b0b92ce997dc..81ba73d77921 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6264,6 +6264,7 @@ int __alloc_contig_migrate_range(struct compact_control *cc,
 	struct migration_target_control mtc = {
 		.nid = zone_to_nid(cc->zone),
 		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
+		.reason = MR_CONTIG_RANGE,
 	};
 
 	lru_cache_disable();
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 87df3a48bdd7..d111c8e3b40e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -978,7 +978,8 @@ static unsigned int demote_folio_list(struct list_head *demote_folios,
 		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) | __GFP_NOWARN |
 			__GFP_NOMEMALLOC | GFP_NOWAIT,
 		.nid = target_nid,
-		.nmask = &allowed_mask
+		.nmask = &allowed_mask,
+		.reason = MR_DEMOTION,
 	};
 
 	if (list_empty(demote_folios))
-- 
2.39.3