mm/page_alloc: remove ifdefs from pindex helpers

The ifdefs are not technically needed here, everything used here is
always defined.

Switching to IS_ENABLED() makes the code a bit less tiresome to read.

Link: https://lore.kernel.org/20260513-page_alloc-unmapped-prep-v1-4-dacdf5402be8@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0278d642445ad4047aac493580893ab5c634590e..dc09a25203138d3cf9455cee2111929df7878c64 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -650,19 +650,17 @@ out:
 
 static inline unsigned int order_to_pindex(int migratetype, int order)
 {
+       if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
+               bool movable = migratetype == MIGRATE_MOVABLE;
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-       bool movable;
-       if (order > PAGE_ALLOC_COSTLY_ORDER) {
-               VM_BUG_ON(!is_pmd_order(order));
-
-               movable = migratetype == MIGRATE_MOVABLE;
+               if (order > PAGE_ALLOC_COSTLY_ORDER) {
+                       VM_BUG_ON(!is_pmd_order(order));
 
-               return NR_LOWORDER_PCP_LISTS + movable;
+                       return NR_LOWORDER_PCP_LISTS + movable;
+               }
+       } else {
+               VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
        }
-#else
-       VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
-#endif
 
        return (MIGRATE_PCPTYPES * order) + migratetype;
 }
@@ -671,12 +669,12 @@ static inline int pindex_to_order(unsigned int pindex)
 {
        int order = pindex / MIGRATE_PCPTYPES;
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-       if (pindex >= NR_LOWORDER_PCP_LISTS)
-               order = HPAGE_PMD_ORDER;
-#else
-       VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
-#endif
+       if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
+               if (pindex >= NR_LOWORDER_PCP_LISTS)
+                       order = HPAGE_PMD_ORDER;
+       } else {
+               VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
+       }
 
        return order;
 }