[PATCH memcg] memcg: enable memory accounting in __alloc_pages_bulk

Vasily Averin
2021-10-08T09:23:54Z

Enable memory accounting for bulk page allocator.

Fixes: 387ba26fb1cb ("mm/page_alloc: add a bulk page allocator")
Cc: <stable@vger.kernel.org>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
mm/page_alloc.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 62 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b37435c274cf..602819a232e5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5172,6 +5172,55 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
return true;
}

+#ifdef CONFIG_MEMCG_KMEM
+static bool memcg_bulk_pre_charge_hook(struct obj_cgroup **objcgp, gfp_t gfp,
+ unsigned int nr_pages)
+{
+ struct obj_cgroup *objcg = NULL;
+
+ if (!memcg_kmem_enabled() || !(gfp & __GFP_ACCOUNT))
+ return true;
+
+ objcg = get_obj_cgroup_from_current();
+
+ if (objcg && obj_cgroup_charge(objcg, gfp, nr_pages << PAGE_SHIFT)) {
+ obj_cgroup_put(objcg);
+ return false;
+ }
+ obj_cgroup_get_many(objcg, nr_pages);
+ *objcgp = objcg;
+ return true;
+}
+
+static void memcg_bulk_charge_hook(struct obj_cgroup *objcg,
+ struct page *page)
+{
+ page->memcg_data = (unsigned long)objcg | MEMCG_DATA_KMEM;
+}
+
+static void memcg_bulk_post_charge_hook(struct obj_cgroup *objcg,
+ unsigned int nr_pages)
+{
+ obj_cgroup_uncharge(objcg, nr_pages << PAGE_SHIFT);
+ percpu_ref_put_many(&objcg->refcnt, nr_pages + 1);
+}
+#else
+static bool memcg_bulk_pre_charge_hook(struct obj_cgroup **objcgp, gfp_t gfp,
+ unsigned int nr_pages)
+{
+ return true;
+}
+
+static void memcg_bulk_charge_hook(struct obj_cgroup *objcgp,
+ struct page *page)
+{
+}
+
+static void memcg_bulk_post_charge_hook(struct obj_cgroup *objcg,
+ unsigned int nr_pages)
+{
+}
+#endif
/*
* __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
* @gfp: GFP flags for the allocation
@@ -5207,6 +5256,8 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
gfp_t alloc_gfp;
unsigned int alloc_flags = ALLOC_WMARK_LOW;
int nr_populated = 0, nr_account = 0;
+ unsigned int nr_pre_charge = 0;
+ struct obj_cgroup *objcg = NULL;

/*
* Skip populated array elements to determine if any pages need
@@ -5275,6 +5326,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
if (unlikely(!zone))
goto failed;

+ nr_pre_charge = nr_pages - nr_populated;
+ if (!memcg_bulk_pre_charge_hook(&objcg, gfp, nr_pre_charge))
+ goto failed;
+
/* Attempt the batch allocation */
local_lock_irqsave(&pagesets.lock, flags);
pcp = this_cpu_ptr(zone->per_cpu_pageset);
@@ -5287,9 +5342,9 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
nr_populated++;
continue;
}
-
page = __rmqueue_pcplist(zone, 0, ac.migratetype, alloc_flags,
pcp, pcp_list);
+
if (unlikely(!page)) {
/* Try and get at least one page */
if (!nr_populated)
@@ -5297,6 +5352,8 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
break;
}
nr_account++;
+ if (objcg)
+ memcg_bulk_charge_hook(objcg, page);

prep_new_page(page, 0, gfp, 0);
if (page_list)
@@ -5310,13 +5367,16 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,

__count_zid_vm_events(PGALLOC, zone_idx(zone), nr_account);
zone_statistics(ac.preferred_zoneref->zone, zone, nr_account);
+ if (objcg)
+ memcg_bulk_post_charge_hook(objcg, nr_pre_charge - nr_account);

out:
return nr_populated;

failed_irq:
local_unlock_irqrestore(&pagesets.lock, flags);
-
+ if (objcg)
+ memcg_bulk_post_charge_hook(objcg, nr_pre_charge);
failed:
page = __alloc_pages(gfp, 0, preferred_nid, nodemask);
if (page) {
--
2.31.1