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

Dev Jain
2024-12-16T16:52:00Z

Pass order to alloc_charge_folio() and update mTHP statistics.

Signed-off-by: Dev Jain <dev.jain@arm.com>
---
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