[PATCH 06/12] hugetlb: perform vmemmap optimization on a list of pages

[Mike Kravetz]

When adding hugetlb pages to the pool, we first create a list of the
allocated pages before adding to the pool.  Pass this list of pages to a
new routine hugetlb_vmemmap_optimize_folios() for vmemmap optimization.

We also modify the routine vmemmap_should_optimize() to check for pages
that are already optimized.  There are code paths that might request
vmemmap optimization twice and we want to make sure this is not
attempted.

Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
 mm/hugetlb.c         |  8 ++++++++
 mm/hugetlb_vmemmap.c | 11 +++++++++++
 mm/hugetlb_vmemmap.h |  5 +++++
 3 files changed, 24 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 452e7ed6dc36..3133dbd89696 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2223,6 +2223,14 @@ static void prep_and_add_allocated_folios(struct hstate *h,
 {
 	struct folio *folio, *tmp_f;
 
+	/*
+	 * Send list for bulk vmemmap optimization processing.
+	 * prep_new_hugetlb_folio (called from prep_and_add_pool_folio)
+	 * will also attempt to perform vmemmap optimization, but this
+	 * is a NOOP if already done.
+	 */
+	hugetlb_vmemmap_optimize_folios(h, folio_list);
+
 	list_for_each_entry_safe(folio, tmp_f, folio_list, lru)
 		prep_and_add_pool_folio(h, folio);
 
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 4b9734777f69..147018a504a6 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -482,6 +482,9 @@ int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head)
 /* Return true iff a HugeTLB whose vmemmap should and can be optimized. */
 static bool vmemmap_should_optimize(const struct hstate *h, const struct page *head)
 {
+	if (HPageVmemmapOptimized((struct page *)head))
+		return false;
+
 	if (!READ_ONCE(vmemmap_optimize_enabled))
 		return false;
 
@@ -570,6 +573,14 @@ void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
 		SetHPageVmemmapOptimized(head);
 }
 
+void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list)
+{
+	struct folio *folio;
+
+	list_for_each_entry(folio, folio_list, lru)
+		hugetlb_vmemmap_optimize(h, &folio->page);
+}
+
 static struct ctl_table hugetlb_vmemmap_sysctls[] = {
 	{
 		.procname	= "hugetlb_optimize_vmemmap",
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
index 25bd0e002431..036494e040ca 100644
--- a/mm/hugetlb_vmemmap.h
+++ b/mm/hugetlb_vmemmap.h
@@ -13,6 +13,7 @@
 #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head);
 void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head);
+void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list);
 
 /*
  * Reserve one vmemmap page, all vmemmap addresses are mapped to it. See
@@ -47,6 +48,10 @@ static inline void hugetlb_vmemmap_optimize(const struct hstate *h, struct page
 {
 }
 
+static inline void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list)
+{
+}
+
 static inline unsigned int hugetlb_vmemmap_optimizable_size(const struct hstate *h)
 {
 	return 0;
-- 
2.41.0