mm/vmalloc.c: change purge_ndoes as local static variable

Patch series "mm/vmalloc.c: code cleanup and improvements", v2.

These changes were made from code inspection in mm/vmalloc.c.

This patch (of 5):

Static variable 'purge_ndoes' is defined in global scope, while it's only
used in function __purge_vmap_area_lazy().  It mainly serves to avoid
memory allocation repeatedly, especially when NR_CPUS is big.

While a local static variable can also satisfy the demand, and can improve
code readibility.  Hence move its definition into
__purge_vmap_area_lazy().

Link: https://lkml.kernel.org/r/20250418223653.243436-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20250418223653.243436-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Shivank Garg <shivankg@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3fd802134e4eadf3993fc8d2e773dbf17856be61..cd733387b1a072f4720223a80a7c6723d2fa912f 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2127,7 +2127,6 @@ static DEFINE_MUTEX(vmap_purge_lock);
 
 /* for per-CPU blocks */
 static void purge_fragmented_blocks_allcpus(void);
-static cpumask_t purge_nodes;
 
 static void
 reclaim_list_global(struct list_head *head)
@@ -2260,6 +2259,7 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end,
 {
        unsigned long nr_purged_areas = 0;
        unsigned int nr_purge_helpers;
+       static cpumask_t purge_nodes;
        unsigned int nr_purge_nodes;
        struct vmap_node *vn;
        int i;