[RFC PATCH 02/12] khugepaged: Generalize alloc_charge_folio()

[Dev Jain <dev.jain@xxxxxxx>]

Pass order to alloc_charge_folio() and update mTHP statistics.

Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
---
 include/linux/huge_mm.h |  2 ++
 mm/huge_memory.c        |  4 ++++
 mm/khugepaged.c         | 13 +++++++++----
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 93e509b6c00e..8b6d0fed99b3 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -119,6 +119,8 @@ enum mthp_stat_item {
 	MTHP_STAT_ANON_FAULT_ALLOC,
 	MTHP_STAT_ANON_FAULT_FALLBACK,
 	MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
+	MTHP_STAT_ANON_COLLAPSE_ALLOC,
+	MTHP_STAT_ANON_COLLAPSE_ALLOC_FAILED,
 	MTHP_STAT_ZSWPOUT,
 	MTHP_STAT_SWPIN,
 	MTHP_STAT_SWPIN_FALLBACK,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 2da5520bfe24..2e582fad4c77 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -615,6 +615,8 @@ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 DEFINE_MTHP_STAT_ATTR(anon_fault_alloc, MTHP_STAT_ANON_FAULT_ALLOC);
 DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_STAT_ANON_FAULT_FALLBACK);
 DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE);
+DEFINE_MTHP_STAT_ATTR(anon_collapse_alloc, MTHP_STAT_ANON_COLLAPSE_ALLOC);
+DEFINE_MTHP_STAT_ATTR(anon_collapse_alloc_failed, MTHP_STAT_ANON_COLLAPSE_ALLOC_FAILED);
 DEFINE_MTHP_STAT_ATTR(zswpout, MTHP_STAT_ZSWPOUT);
 DEFINE_MTHP_STAT_ATTR(swpin, MTHP_STAT_SWPIN);
 DEFINE_MTHP_STAT_ATTR(swpin_fallback, MTHP_STAT_SWPIN_FALLBACK);
@@ -636,6 +638,8 @@ static struct attribute *anon_stats_attrs[] = {
 	&anon_fault_alloc_attr.attr,
 	&anon_fault_fallback_attr.attr,
 	&anon_fault_fallback_charge_attr.attr,
+	&anon_collapse_alloc_attr.attr,
+	&anon_collapse_alloc_failed_attr.attr,
 #ifndef CONFIG_SHMEM
 	&zswpout_attr.attr,
 	&swpin_attr.attr,
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 95643e6e5f31..02cd424b8e48 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1073,21 +1073,26 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm,
 }
 
 static int alloc_charge_folio(struct folio **foliop, struct mm_struct *mm,
-			      struct collapse_control *cc)
+			      int order, struct collapse_control *cc)
 {
 	gfp_t gfp = (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() :
 		     GFP_TRANSHUGE);
 	int node = hpage_collapse_find_target_node(cc);
 	struct folio *folio;
 
-	folio = __folio_alloc(gfp, HPAGE_PMD_ORDER, node, &cc->alloc_nmask);
+	folio = __folio_alloc(gfp, order, node, &cc->alloc_nmask);
 	if (!folio) {
 		*foliop = NULL;
 		count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+		if (order != HPAGE_PMD_ORDER)
+			count_mthp_stat(order, MTHP_STAT_ANON_COLLAPSE_ALLOC_FAILED);
 		return SCAN_ALLOC_HUGE_PAGE_FAIL;
 	}
 
 	count_vm_event(THP_COLLAPSE_ALLOC);
+	if (order != HPAGE_PMD_ORDER)
+		count_mthp_stat(order, MTHP_STAT_ANON_COLLAPSE_ALLOC);
+
 	if (unlikely(mem_cgroup_charge(folio, mm, gfp))) {
 		folio_put(folio);
 		*foliop = NULL;
@@ -1124,7 +1129,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	 */
 	mmap_read_unlock(mm);
 
-	result = alloc_charge_folio(&folio, mm, cc);
+	result = alloc_charge_folio(&folio, mm, order, cc);
 	if (result != SCAN_SUCCEED)
 		goto out_nolock;
 
@@ -1850,7 +1855,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 	VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
 	VM_BUG_ON(start & (HPAGE_PMD_NR - 1));
 
-	result = alloc_charge_folio(&new_folio, mm, cc);
+	result = alloc_charge_folio(&new_folio, mm, HPAGE_PMD_ORDER, cc);
 	if (result != SCAN_SUCCEED)
 		goto out;
 
-- 
2.30.2