The patch titled
Subject: mm: add per-order mTHP split counters
has been added to the -mm mm-unstable branch. Its filename is
mm-add-per-order-mthp-split-counters.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-per-order-mthp-split-counters.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Lance Yang <ioworker0@xxxxxxxxx>
Subject: mm: add per-order mTHP split counters
Date: Fri, 28 Jun 2024 21:07:49 +0800
Patch series "mm: introduce per-order mTHP split counters", v2.
Currently, the split counters in THP statistics no longer include
PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
counters to monitor the frequency of mTHP splits. This will help
developers better analyze and optimize system performance.
/sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
split
split_failed
split_deferred
This patch (of 2):
Currently, the split counters in THP statistics no longer include
PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split
counters to monitor the frequency of mTHP splits. This will help
developers better analyze and optimize system performance.
/sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
split
split_failed
split_deferred
Link: https://lkml.kernel.org/r/20240628130750.73097-1-ioworker0@xxxxxxxxx
Link: https://lkml.kernel.org/r/20240628130750.73097-2-ioworker0@xxxxxxxxx
Signed-off-by: Mingzhe Yang <mingzhe.yang@xxxxxx>
Signed-off-by: Lance Yang <ioworker0@xxxxxxxxx>
Cc: Bang Li <libang.li@xxxxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/huge_mm.h | 3 +++
mm/huge_memory.c | 19 ++++++++++++++-----
2 files changed, 17 insertions(+), 5 deletions(-)
--- a/include/linux/huge_mm.h~mm-add-per-order-mthp-split-counters
+++ a/include/linux/huge_mm.h
@@ -284,6 +284,9 @@ enum mthp_stat_item {
MTHP_STAT_FILE_ALLOC,
MTHP_STAT_FILE_FALLBACK,
MTHP_STAT_FILE_FALLBACK_CHARGE,
+ MTHP_STAT_SPLIT,
+ MTHP_STAT_SPLIT_FAILED,
+ MTHP_STAT_SPLIT_DEFERRED,
__MTHP_STAT_COUNT
};
--- a/mm/huge_memory.c~mm-add-per-order-mthp-split-counters
+++ a/mm/huge_memory.c
@@ -559,6 +559,9 @@ DEFINE_MTHP_STAT_ATTR(swpout_fallback, M
DEFINE_MTHP_STAT_ATTR(file_alloc, MTHP_STAT_FILE_ALLOC);
DEFINE_MTHP_STAT_ATTR(file_fallback, MTHP_STAT_FILE_FALLBACK);
DEFINE_MTHP_STAT_ATTR(file_fallback_charge, MTHP_STAT_FILE_FALLBACK_CHARGE);
+DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT);
+DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED);
+DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED);
static struct attribute *stats_attrs[] = {
&anon_fault_alloc_attr.attr,
@@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] =
&file_alloc_attr.attr,
&file_fallback_attr.attr,
&file_fallback_charge_attr.attr,
+ &split_attr.attr,
+ &split_failed_attr.attr,
+ &split_deferred_attr.attr,
NULL,
};
@@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(str
XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order);
struct anon_vma *anon_vma = NULL;
struct address_space *mapping = NULL;
- bool is_thp = folio_test_pmd_mappable(folio);
+ int order = folio_order(folio);
int extra_pins, ret;
pgoff_t end;
bool is_hzp;
@@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(str
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
- if (new_order >= folio_order(folio))
+ if (new_order >= order)
return -EINVAL;
if (folio_test_anon(folio)) {
@@ -3253,8 +3259,9 @@ out_unlock:
i_mmap_unlock_read(mapping);
out:
xas_destroy(&xas);
- if (is_thp)
+ if (order >= HPAGE_PMD_ORDER)
count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
+ count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED);
return ret;
}
@@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *
#ifdef CONFIG_MEMCG
struct mem_cgroup *memcg = folio_memcg(folio);
#endif
+ int order = folio_order(folio);
unsigned long flags;
/*
* Order 1 folios have no space for a deferred list, but we also
* won't waste much memory by not adding them to the deferred list.
*/
- if (folio_order(folio) <= 1)
+ if (order <= 1)
return;
/*
@@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *
spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
if (list_empty(&folio->_deferred_list)) {
- if (folio_test_pmd_mappable(folio))
+ if (order >= HPAGE_PMD_ORDER)
count_vm_event(THP_DEFERRED_SPLIT_PAGE);
+ count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED);
list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
ds_queue->split_queue_len++;
#ifdef CONFIG_MEMCG
_
Patches currently in -mm which might be from ioworker0@xxxxxxxxx are
mm-add-per-order-mthp-split-counters.patch
mm-add-docs-for-per-order-mthp-split-counters.patch
