[PATCH v6 04/12] khugepaged: generalize alloc_charge_folio()

[Nico Pache]

From: Dev Jain <dev.j...@arm.com>

Pass order to alloc_charge_folio() and update mTHP statistics.

Reviewed-by: Baolin Wang <baolin.w...@linux.alibaba.com>
Co-developed-by: Nico Pache <npa...@redhat.com>
Signed-off-by: Nico Pache <npa...@redhat.com>
Signed-off-by: Dev Jain <dev.j...@arm.com>
---
 include/linux/huge_mm.h |  2 ++
 mm/huge_memory.c        |  4 ++++
 mm/khugepaged.c         | 17 +++++++++++------
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 2f190c90192d..0bb65bd4e6dd 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -123,6 +123,8 @@ enum mthp_stat_item {
        MTHP_STAT_ANON_FAULT_ALLOC,
        MTHP_STAT_ANON_FAULT_FALLBACK,
        MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
+       MTHP_STAT_COLLAPSE_ALLOC,
+       MTHP_STAT_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 d3e66136e41a..177f0a78666a 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(collapse_alloc, MTHP_STAT_COLLAPSE_ALLOC);
+DEFINE_MTHP_STAT_ATTR(collapse_alloc_failed, MTHP_STAT_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);
@@ -680,6 +682,8 @@ static struct attribute *any_stats_attrs[] = {
 #endif
        &split_attr.attr,
        &split_failed_attr.attr,
+       &collapse_alloc_attr.attr,
+       &collapse_alloc_failed_attr.attr,
        NULL,
 };
 
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0c4d6a02d59c..cf94ccdfe751 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1074,21 +1074,26 @@ 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)
+                             struct collapse_control *cc, u8 order)
 {
        gfp_t gfp = (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() :
                     GFP_TRANSHUGE);
        int node = khugepaged_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_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+               count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC_FAILED);
                return SCAN_ALLOC_HUGE_PAGE_FAIL;
        }
 
-       count_vm_event(THP_COLLAPSE_ALLOC);
+       if (order == HPAGE_PMD_ORDER)
+               count_vm_event(THP_COLLAPSE_ALLOC);
+       count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC);
+
        if (unlikely(mem_cgroup_charge(folio, mm, gfp))) {
                folio_put(folio);
                *foliop = NULL;
@@ -1125,7 +1130,7 @@ 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, cc, HPAGE_PMD_ORDER);
        if (result != SCAN_SUCCEED)
                goto out_nolock;
 
@@ -1847,7 +1852,7 @@ 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, cc, HPAGE_PMD_ORDER);
        if (result != SCAN_SUCCEED)
                goto out;
 
-- 
2.49.0