[PATCH] mm/hugetlb: Perform vmemmap optimization batchly for specific node allocation

From: suhua
Date: Sat Oct 12 2024 - 03:08:18 EST


When HVO is enabled and huge page memory allocs are made, the freed memory
can be aggregated into higher order memory in the following paths, which
facilitates further allocs for higher order memory.

echo 200000 > /proc/sys/vm/nr_hugepages
echo 200000 > /sys/devices/system/node/node*/hugepages/hugepages-2048kB/nr_hugepages
grub: default_hugepagesz=2M hugepagesz=2M hugepages=200000

Currently not support for releasing aggregations to higher order in the
following way, which will releasing to lower order.

grub: default_hugepagesz=2M hugepagesz=2M hugepages=0:100000,1:100000

This patch supports the release of huge page optimizations aggregates to
higher order memory.

eg:
cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-xxx ... default_hugepagesz=2M hugepagesz=2M hugepages=0:100000,1:100000

Before:
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
...
Node 0, zone Normal, type Unmovable 55282 97039 99307 0 1 1 0 1 1 1 0
Node 0, zone Normal, type Movable 25 11 345 87 48 21 2 20 9 3 75061
Node 0, zone Normal, type Reclaimable 4 2 2 4 3 0 2 1 1 1 0
Node 0, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0
...
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 1, zone Normal, type Unmovable 98888 99650 99679 2 3 1 2 2 2 0 0
Node 1, zone Normal, type Movable 1 1 0 1 1 0 1 0 1 1 75937
Node 1, zone Normal, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 1, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0

After:
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
...
Node 0, zone Normal, type Unmovable 152 158 37 2 2 0 3 4 2 6 717
Node 0, zone Normal, type Movable 1 37 53 3 55 49 16 6 2 1 75000
Node 0, zone Normal, type Reclaimable 1 4 3 1 2 1 1 1 1 1 0
Node 0, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0
...
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 1, zone Normal, type Unmovable 5 3 2 1 3 4 2 2 2 0 779
Node 1, zone Normal, type Movable 1 0 1 1 1 0 1 0 1 1 75849
Node 1, zone Normal, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 1, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0

Signed-off-by: suhua <suhua1@xxxxxxxxxxxx>
---
mm/hugetlb.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 190fa05635f4..906294ac85dc 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3301,6 +3301,7 @@ static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
{
unsigned long i;
char buf[32];
+ LIST_HEAD(folio_list);

for (i = 0; i < h->max_huge_pages_node[nid]; ++i) {
if (hstate_is_gigantic(h)) {
@@ -3310,14 +3311,18 @@ static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
struct folio *folio;
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;

- folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid,
- &node_states[N_MEMORY]);
+ folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, nid,
+ &node_states[N_MEMORY], NULL);
if (!folio)
break;
- free_huge_folio(folio); /* free it into the hugepage allocator */
+ list_add(&folio->lru, &folio_list);
}
cond_resched();
}
+
+ if (!list_empty(&folio_list))
+ prep_and_add_allocated_folios(h, &folio_list);
+
if (i == h->max_huge_pages_node[nid])
return;

--
2.34.1