[PATCH v5 4/7] hugetlb: pass *next_nid_to_alloc directly to for_each_node_mask_to_alloc

From: Gang Li
Date: Fri Jan 26 2024 - 10:26:12 EST


With parallelization of hugetlb allocation across different threads, each
thread works on a differnet node to allocate pages from, instead of all
allocating from a common node h->next_nid_to_alloc. To address this, it's
necessary to assign a separate next_nid_to_alloc for each thread.

Consequently, the hstate_next_node_to_alloc and for_each_node_mask_to_alloc
have been modified to directly accept a *next_nid_to_alloc parameter,
ensuring thread-specific allocation and avoiding concurrent access issues.

Signed-off-by: Gang Li <ligang.bdlg@xxxxxxxxxxxxx>
Tested-by: David Rientjes <rientjes@xxxxxxxxxx>
Reviewed-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Reviewed-by: Muchun Song <muchun.song@xxxxxxxxx>
---
mm/hugetlb.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 00bbf7442eb6c..e4e8ffa1c145a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1464,15 +1464,15 @@ static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
* next node from which to allocate, handling wrap at end of node
* mask.
*/
-static int hstate_next_node_to_alloc(struct hstate *h,
+static int hstate_next_node_to_alloc(int *next_node,
nodemask_t *nodes_allowed)
{
int nid;

VM_BUG_ON(!nodes_allowed);

- nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
- h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);
+ nid = get_valid_node_allowed(*next_node, nodes_allowed);
+ *next_node = next_node_allowed(nid, nodes_allowed);

return nid;
}
@@ -1495,10 +1495,10 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
return nid;
}

-#define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \
+#define for_each_node_mask_to_alloc(next_node, nr_nodes, node, mask) \
for (nr_nodes = nodes_weight(*mask); \
nr_nodes > 0 && \
- ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \
+ ((node = hstate_next_node_to_alloc(next_node, mask)) || 1); \
nr_nodes--)

#define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
@@ -2350,12 +2350,13 @@ static void prep_and_add_allocated_folios(struct hstate *h,
*/
static struct folio *alloc_pool_huge_folio(struct hstate *h,
nodemask_t *nodes_allowed,
- nodemask_t *node_alloc_noretry)
+ nodemask_t *node_alloc_noretry,
+ int *next_node)
{
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
int nr_nodes, node;

- for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
+ for_each_node_mask_to_alloc(next_node, nr_nodes, node, nodes_allowed) {
struct folio *folio;

folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, node,
@@ -3310,7 +3311,7 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid)
goto found;
}
/* allocate from next node when distributing huge pages */
- for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
+ for_each_node_mask_to_alloc(&h->next_nid_to_alloc, nr_nodes, node, &node_states[N_MEMORY]) {
m = memblock_alloc_try_nid_raw(
huge_page_size(h), huge_page_size(h),
0, MEMBLOCK_ALLOC_ACCESSIBLE, node);
@@ -3679,7 +3680,7 @@ static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
VM_BUG_ON(delta != -1 && delta != 1);

if (delta < 0) {
- for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
+ for_each_node_mask_to_alloc(&h->next_nid_to_alloc, nr_nodes, node, nodes_allowed) {
if (h->surplus_huge_pages_node[node])
goto found;
}
@@ -3794,7 +3795,8 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
cond_resched();

folio = alloc_pool_huge_folio(h, nodes_allowed,
- node_alloc_noretry);
+ node_alloc_noretry,
+ &h->next_nid_to_alloc);
if (!folio) {
prep_and_add_allocated_folios(h, &page_list);
spin_lock_irq(&hugetlb_lock);
--
2.20.1