From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Thu, 6 Nov 2025 20:14:49 +0000 (+0000)
Subject: migrate: optimise alloc_migration_target()
X-Git-Tag: v6.19-rc1~112^2~145
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c537f0dd30344434b6e7585768d3fa38190d2d0c;p=thirdparty%2Fkernel%2Flinux.git

migrate: optimise alloc_migration_target()

Extract the zone number directly from the folio instead of using the
folio's zone number to look up the zone and asking the zone what its
number is.

[ziy@nvidia.com: fix folio_zonenum() return type]
  Link: https://lkml.kernel.org/r/26E8FF35-503E-4F14-98F7-7B4FA25FBD37@nvidia.com
Link: https://lkml.kernel.org/r/20251106201452.2292631-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Ying Huang <ying.huang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/migrate.c b/mm/migrate.c
index 7c5d2efb9d47a..08d034dbeb988 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2164,7 +2164,7 @@ struct folio *alloc_migration_target(struct folio *src, unsigned long private)
 	gfp_t gfp_mask;
 	unsigned int order = 0;
 	int nid;
-	int zidx;
+	enum zone_type zidx;
 
 	mtc = (struct migration_target_control *)private;
 	gfp_mask = mtc->gfp_mask;
@@ -2190,7 +2190,7 @@ struct folio *alloc_migration_target(struct folio *src, unsigned long private)
 		gfp_mask |= GFP_TRANSHUGE;
 		order = folio_order(src);
 	}
-	zidx = zone_idx(folio_zone(src));
+	zidx = folio_zonenum(src);
 	if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE)
 		gfp_mask |= __GFP_HIGHMEM;