[PATCH 1/8] migrate_pages: organize stats with struct migrate_pages_stats

Huang Ying
2022-12-27T00:29:37Z

Define struct migrate_pages_stats to organize the various statistics
in migrate_pages(). This makes it easier to collect and consume the
statistics in multiple functions. This will be needed in the
following patches in the series.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: haoxin <xhao@linux.alibaba.com>
---
mm/migrate.c | 58 +++++++++++++++++++++++++++++-----------------------
1 file changed, 32 insertions(+), 26 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index a4d3fc65085f..ec9263a33d38 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1396,6 +1396,14 @@ static inline int try_split_folio(struct folio *folio, struct list_head *split_f
return rc;
}

+struct migrate_pages_stats {
+ int nr_succeeded;
+ int nr_failed_pages;
+ int nr_thp_succeeded;
+ int nr_thp_failed;
+ int nr_thp_split;
+};
+
/*
* migrate_pages - migrate the folios specified in a list, to the free folios
* supplied as the target for the page migration
@@ -1430,13 +1438,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
int large_retry = 1;
int thp_retry = 1;
int nr_failed = 0;
- int nr_failed_pages = 0;
int nr_retry_pages = 0;
- int nr_succeeded = 0;
- int nr_thp_succeeded = 0;
int nr_large_failed = 0;
- int nr_thp_failed = 0;
- int nr_thp_split = 0;
int pass = 0;
bool is_large = false;
bool is_thp = false;
@@ -1446,9 +1449,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
LIST_HEAD(split_folios);
bool nosplit = (reason == MR_NUMA_MISPLACED);
bool no_split_folio_counting = false;
+ struct migrate_pages_stats stats;

trace_mm_migrate_pages_start(mode, reason);

+ memset(&stats, 0, sizeof(stats));
split_folio_migration:
for (pass = 0; pass < 10 && (retry || large_retry); pass++) {
retry = 0;
@@ -1502,9 +1507,9 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
/* Large folio migration is unsupported */
if (is_large) {
nr_large_failed++;
- nr_thp_failed += is_thp;
+ stats.nr_thp_failed += is_thp;
if (!try_split_folio(folio, &split_folios)) {
- nr_thp_split += is_thp;
+ stats.nr_thp_split += is_thp;
break;
}
/* Hugetlb migration is unsupported */
@@ -1512,7 +1517,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_failed++;
}

- nr_failed_pages += nr_pages;
+ stats.nr_failed_pages += nr_pages;
list_move_tail(&folio->lru, &ret_folios);
break;
case -ENOMEM:
@@ -1522,13 +1527,13 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
*/
if (is_large) {
nr_large_failed++;
- nr_thp_failed += is_thp;
+ stats.nr_thp_failed += is_thp;
/* Large folio NUMA faulting doesn't split to retry. */
if (!nosplit) {
int ret = try_split_folio(folio, &split_folios);

if (!ret) {
- nr_thp_split += is_thp;
+ stats.nr_thp_split += is_thp;
break;
} else if (reason == MR_LONGTERM_PIN &&
ret == -EAGAIN) {
@@ -1546,7 +1551,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_failed++;
}

- nr_failed_pages += nr_pages + nr_retry_pages;
+ stats.nr_failed_pages += nr_pages + nr_retry_pages;
/*
* There might be some split folios of fail-to-migrate large
* folios left in split_folios list. Move them back to migration
@@ -1556,7 +1561,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
list_splice_init(&split_folios, from);
/* nr_failed isn't updated for not used */
nr_large_failed += large_retry;
- nr_thp_failed += thp_retry;
+ stats.nr_thp_failed += thp_retry;
goto out;
case -EAGAIN:
if (is_large) {
@@ -1568,8 +1573,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_retry_pages += nr_pages;
break;
case MIGRATEPAGE_SUCCESS:
- nr_succeeded += nr_pages;
- nr_thp_succeeded += is_thp;
+ stats.nr_succeeded += nr_pages;
+ stats.nr_thp_succeeded += is_thp;
break;
default:
/*
@@ -1580,20 +1585,20 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
*/
if (is_large) {
nr_large_failed++;
- nr_thp_failed += is_thp;
+ stats.nr_thp_failed += is_thp;
} else if (!no_split_folio_counting) {
nr_failed++;
}

- nr_failed_pages += nr_pages;
+ stats.nr_failed_pages += nr_pages;
break;
}
}
}
nr_failed += retry;
nr_large_failed += large_retry;
- nr_thp_failed += thp_retry;
- nr_failed_pages += nr_retry_pages;
+ stats.nr_thp_failed += thp_retry;
+ stats.nr_failed_pages += nr_retry_pages;
/*
* Try to migrate split folios of fail-to-migrate large folios, no
* nr_failed counting in this round, since all split folios of a
@@ -1626,16 +1631,17 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
if (list_empty(from))
rc = 0;

- count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded);
- count_vm_events(PGMIGRATE_FAIL, nr_failed_pages);
- 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);
- trace_mm_migrate_pages(nr_succeeded, nr_failed_pages, nr_thp_succeeded,
- nr_thp_failed, nr_thp_split, mode, reason);
+ count_vm_events(PGMIGRATE_SUCCESS, stats.nr_succeeded);
+ count_vm_events(PGMIGRATE_FAIL, stats.nr_failed_pages);
+ count_vm_events(THP_MIGRATION_SUCCESS, stats.nr_thp_succeeded);
+ count_vm_events(THP_MIGRATION_FAIL, stats.nr_thp_failed);
+ count_vm_events(THP_MIGRATION_SPLIT, stats.nr_thp_split);
+ trace_mm_migrate_pages(stats.nr_succeeded, stats.nr_failed_pages,
+ stats.nr_thp_succeeded, stats.nr_thp_failed,
+ stats.nr_thp_split, mode, reason);

if (ret_succeeded)
- *ret_succeeded = nr_succeeded;
+ *ret_succeeded = stats.nr_succeeded;

return rc;
}
--
2.35.1