[RFC] mm/vmstat: Add events for HugeTLB migration
From: Anshuman Khandual
Date: Fri Sep 25 2020 - 05:13:23 EST
Add following new vmstat events which will track HugeTLB page migration.
1. HUGETLB_MIGRATION_SUCCESS
2. HUGETLB_MIGRATION_FAILURE
It follows the existing semantics to accommodate HugeTLB subpages in total
page migration statistics. While here, this updates current trace event
"mm_migrate_pages" to accommodate now available HugeTLB based statistics.
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
This is just for getting some early feedbacks. Applies on linux-next and
lightly tested for THP and HugeTLB migrations.
include/linux/vm_event_item.h | 2 ++
include/trace/events/migrate.h | 13 +++++++++---
mm/migrate.c | 37 ++++++++++++++++++++++++++++++++--
mm/vmstat.c | 2 ++
4 files changed, 49 insertions(+), 5 deletions(-)
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 18e75974d4e3..d1ddad835c19 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -60,6 +60,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
THP_MIGRATION_SUCCESS,
THP_MIGRATION_FAIL,
THP_MIGRATION_SPLIT,
+ HUGETLB_MIGRATION_SUCCESS,
+ HUGETLB_MIGRATION_FAIL,
#endif
#ifdef CONFIG_COMPACTION
COMPACTMIGRATE_SCANNED, COMPACTFREE_SCANNED,
diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h
index 4d434398d64d..f8ffb8aece48 100644
--- a/include/trace/events/migrate.h
+++ b/include/trace/events/migrate.h
@@ -47,10 +47,11 @@ TRACE_EVENT(mm_migrate_pages,
TP_PROTO(unsigned long succeeded, unsigned long failed,
unsigned long thp_succeeded, unsigned long thp_failed,
- unsigned long thp_split, enum migrate_mode mode, int reason),
+ unsigned long thp_split, unsigned long hugetlb_succeeded,
+ unsigned long hugetlb_failed, enum migrate_mode mode, int reason),
TP_ARGS(succeeded, failed, thp_succeeded, thp_failed,
- thp_split, mode, reason),
+ thp_split, hugetlb_succeeded, hugetlb_failed, mode, reason),
TP_STRUCT__entry(
__field( unsigned long, succeeded)
@@ -58,6 +59,8 @@ TRACE_EVENT(mm_migrate_pages,
__field( unsigned long, thp_succeeded)
__field( unsigned long, thp_failed)
__field( unsigned long, thp_split)
+ __field( unsigned long, hugetlb_succeeded)
+ __field( unsigned long, hugetlb_failed)
__field( enum migrate_mode, mode)
__field( int, reason)
),
@@ -68,16 +71,20 @@ TRACE_EVENT(mm_migrate_pages,
__entry->thp_succeeded = thp_succeeded;
__entry->thp_failed = thp_failed;
__entry->thp_split = thp_split;
+ __entry->hugetlb_succeeded = hugetlb_succeeded;
+ __entry->hugetlb_failed = hugetlb_failed;
__entry->mode = mode;
__entry->reason = reason;
),
- TP_printk("nr_succeeded=%lu nr_failed=%lu nr_thp_succeeded=%lu nr_thp_failed=%lu nr_thp_split=%lu mode=%s reason=%s",
+ TP_printk("nr_succeeded=%lu nr_failed=%lu nr_thp_succeeded=%lu nr_thp_failed=%lu nr_thp_split=%lu nr_hugetlb_succeeded=%lu nr_hugetlb_failed=%lu mode=%s reason=%s",
__entry->succeeded,
__entry->failed,
__entry->thp_succeeded,
__entry->thp_failed,
__entry->thp_split,
+ __entry->hugetlb_succeeded,
+ __entry->hugetlb_failed,
__print_symbolic(__entry->mode, MIGRATE_MODE),
__print_symbolic(__entry->reason, MIGRATE_REASON))
);
diff --git a/mm/migrate.c b/mm/migrate.c
index 3ab965f83029..d53dd101ffff 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1415,13 +1415,17 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
{
int retry = 1;
int thp_retry = 1;
+ int hugetlb_retry = 1;
int nr_failed = 0;
int nr_succeeded = 0;
int nr_thp_succeeded = 0;
int nr_thp_failed = 0;
int nr_thp_split = 0;
+ int nr_hugetlb_succeeded = 0;
+ int nr_hugetlb_failed = 0;
int pass = 0;
bool is_thp = false;
+ bool is_hugetlb = false;
struct page *page;
struct page *page2;
int swapwrite = current->flags & PF_SWAPWRITE;
@@ -1433,6 +1437,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
for (pass = 0; pass < 10 && (retry || thp_retry); pass++) {
retry = 0;
thp_retry = 0;
+ hugetlb_retry = 0;
list_for_each_entry_safe(page, page2, from, lru) {
retry:
@@ -1442,7 +1447,12 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
* during migration.
*/
is_thp = PageTransHuge(page) && !PageHuge(page);
+ is_hugetlb = PageTransHuge(page) && PageHuge(page);
+
nr_subpages = thp_nr_pages(page);
+ if (is_hugetlb)
+ nr_subpages = pages_per_huge_page(page_hstate(page));
+
cond_resched();
if (PageHuge(page))
@@ -1481,6 +1491,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_failed += nr_subpages;
goto out;
}
+ if (is_hugetlb) {
+ nr_hugetlb_failed++;
+ nr_failed += nr_subpages;
+ goto out;
+ }
nr_failed++;
goto out;
case -EAGAIN:
@@ -1488,6 +1503,10 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
thp_retry++;
break;
}
+ if (is_hugetlb) {
+ hugetlb_retry++;
+ break;
+ }
retry++;
break;
case MIGRATEPAGE_SUCCESS:
@@ -1496,6 +1515,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_succeeded += nr_subpages;
break;
}
+ if (is_hugetlb) {
+ nr_hugetlb_succeeded++;
+ nr_succeeded += nr_subpages;
+ break;
+ }
nr_succeeded++;
break;
default:
@@ -1510,13 +1534,19 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_failed += nr_subpages;
break;
}
+ if (is_hugetlb) {
+ nr_hugetlb_failed++;
+ nr_failed += nr_subpages;
+ break;
+ }
nr_failed++;
break;
}
}
}
- nr_failed += retry + thp_retry;
+ nr_failed += retry + thp_retry + hugetlb_retry;
nr_thp_failed += thp_retry;
+ nr_hugetlb_failed += hugetlb_retry;
rc = nr_failed;
out:
count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded);
@@ -1524,8 +1554,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded);
count_vm_events(THP_MIGRATION_FAIL, nr_thp_failed);
count_vm_events(THP_MIGRATION_SPLIT, nr_thp_split);
+ count_vm_events(HUGETLB_MIGRATION_SUCCESS, nr_hugetlb_succeeded);
+ count_vm_events(HUGETLB_MIGRATION_FAIL, nr_hugetlb_failed);
trace_mm_migrate_pages(nr_succeeded, nr_failed, nr_thp_succeeded,
- nr_thp_failed, nr_thp_split, mode, reason);
+ nr_thp_failed, nr_thp_split, nr_hugetlb_succeeded,
+ nr_hugetlb_failed, mode, reason);
if (!swapwrite)
current->flags &= ~PF_SWAPWRITE;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 79e5cd0abd0e..12fd35ba135f 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1286,6 +1286,8 @@ const char * const vmstat_text[] = {
"thp_migration_success",
"thp_migration_fail",
"thp_migration_split",
+ "hugetlb_migration_success",
+ "hugetlb_migration_fail",
#endif
#ifdef CONFIG_COMPACTION
"compact_migrate_scanned",
--
2.20.1