[PATCH] mm: thp: Fix build warning when CONFIG_SYSFS is disabled

[Ryan Roberts <ryan.roberts@arm.com>]

huge_anon_orders_lock is used only to serialize sysfs writers. So move
its definition so that it is within the CONFIG_SYSFS ifdefery to
suppress "defined but not used" warning when sysfs is disabled.

Fixes: fe2c9313a8c0 ("mm: thp: Introduce multi-size THP sysfs interface")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312111916.YbsHxKPq-lkp@intel.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---

Hi Andrew,

David mentioned that your preference is to squash minor fixes into patches in
mm-unstable? Could you please squash this into commit fe2c9313a8c0 ("mm: thp:
Introduce multi-size THP sysfs interface")?

Thanks,
Ryan

 mm/huge_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index cfb1d04a71b1..ddf73422d3b5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -77,7 +77,6 @@ unsigned long huge_zero_pfn __read_mostly = ~0UL;
 unsigned long huge_anon_orders_always __read_mostly;
 unsigned long huge_anon_orders_madvise __read_mostly;
 unsigned long huge_anon_orders_inherit __read_mostly;
-static DEFINE_SPINLOCK(huge_anon_orders_lock);

 unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
 					 unsigned long vm_flags, bool smaps,
@@ -442,6 +441,7 @@ static const struct attribute_group hugepage_attr_group = {

 static void hugepage_exit_sysfs(struct kobject *hugepage_kobj);
 static void thpsize_release(struct kobject *kobj);
+static DEFINE_SPINLOCK(huge_anon_orders_lock);
 static LIST_HEAD(thpsize_list);

 struct thpsize {
--
2.25.1