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authorShakeel Butt <shakeel.butt@linux.dev>2025-04-02 22:33:26 -0700
committerAndrew Morton <akpm@linux-foundation.org>2025-05-11 17:48:10 -0700
commitaa8d89d1472b010cbcda7288a4da76e4852a260d (patch)
treebb745dfc7f6f3eaf0ba6427cb8c622e603f10d19 /mm
parent98c9389042f4d1e6aa73fbaf79e2e962c9497fc5 (diff)
memcg: vmalloc: simplify MEMCG_VMALLOC updates
The vmalloc region can either be charged to a single memcg or none. At the moment kernel traverses all the pages backing the vmalloc region to update the MEMCG_VMALLOC stat. However there is no need to look at all the pages as all those pages will be charged to a single memcg or none. Simplify the MEMCG_VMALLOC update by just looking at the first page of the vmalloc region. [shakeel.butt@linux.dev: add comment] Link: https://lkml.kernel.org/r/bmlkdbqgwboyqrnxyom7n52fjmo76ux77jhqw5odc6c6dfon3h@zdylwtmlywbt Link: https://lkml.kernel.org/r/20250403053326.26860-1-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmalloc.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2d7511654831..44b735a4573a 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3371,12 +3371,13 @@ void vfree(const void *addr)
if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
vm_reset_perms(vm);
+ /* All pages of vm should be charged to same memcg, so use first one. */
+ if (vm->nr_pages && !(vm->flags & VM_MAP_PUT_PAGES))
+ mod_memcg_page_state(vm->pages[0], MEMCG_VMALLOC, -vm->nr_pages);
for (i = 0; i < vm->nr_pages; i++) {
struct page *page = vm->pages[i];
BUG_ON(!page);
- if (!(vm->flags & VM_MAP_PUT_PAGES))
- mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
/*
* High-order allocs for huge vmallocs are split, so
* can be freed as an array of order-0 allocations
@@ -3672,12 +3673,10 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
node, page_order, nr_small_pages, area->pages);
atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
- if (gfp_mask & __GFP_ACCOUNT) {
- int i;
-
- for (i = 0; i < area->nr_pages; i++)
- mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1);
- }
+ /* All pages of vm should be charged to same memcg, so use first one. */
+ if (gfp_mask & __GFP_ACCOUNT && area->nr_pages)
+ mod_memcg_page_state(area->pages[0], MEMCG_VMALLOC,
+ area->nr_pages);
/*
* If not enough pages were obtained to accomplish an