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authorAnshuman Khandual <anshuman.khandual@arm.com>2020-08-11 18:31:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-12 10:57:57 -0700
commit1a5bae25e3cf95c4e83a97f87a6b5280d9acbb22 (patch)
treedc992bcf615ef29415565caa5d6938e9870d75bc /mm
parent4958e4d86ecb011a81f5d80ce2023ef9f10692d8 (diff)
mm/vmstat: add events for THP migration without split
Add following new vmstat events which will help in validating THP migration without split. Statistics reported through these new VM events will help in performance debugging. 1. THP_MIGRATION_SUCCESS 2. THP_MIGRATION_FAILURE 3. THP_MIGRATION_SPLIT In addition, these new events also update normal page migration statistics appropriately via PGMIGRATE_SUCCESS and PGMIGRATE_FAILURE. While here, this updates current trace event 'mm_migrate_pages' to accommodate now available THP statistics. [akpm@linux-foundation.org: s/hpage_nr_pages/thp_nr_pages/] [ziy@nvidia.com: v2] Link: http://lkml.kernel.org/r/C5E3C65C-8253-4638-9D3C-71A61858BB8B@nvidia.com [anshuman.khandual@arm.com: s/thp_nr_pages/hpage_nr_pages/] Link: http://lkml.kernel.org/r/1594287583-16568-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Link: http://lkml.kernel.org/r/1594080415-27924-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/migrate.c52
-rw-r--r--mm/vmstat.c3
2 files changed, 47 insertions, 8 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index b52f30113366..5ea275878383 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1418,22 +1418,35 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
enum migrate_mode mode, int reason)
{
int retry = 1;
+ int thp_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 pass = 0;
+ bool is_thp = false;
struct page *page;
struct page *page2;
int swapwrite = current->flags & PF_SWAPWRITE;
- int rc;
+ int rc, nr_subpages;
if (!swapwrite)
current->flags |= PF_SWAPWRITE;
- for(pass = 0; pass < 10 && retry; pass++) {
+ for (pass = 0; pass < 10 && (retry || thp_retry); pass++) {
retry = 0;
+ thp_retry = 0;
list_for_each_entry_safe(page, page2, from, lru) {
retry:
+ /*
+ * THP statistics is based on the source huge page.
+ * Capture required information that might get lost
+ * during migration.
+ */
+ is_thp = PageTransHuge(page);
+ nr_subpages = hpage_nr_pages(page);
cond_resched();
if (PageHuge(page))
@@ -1464,15 +1477,30 @@ retry:
unlock_page(page);
if (!rc) {
list_safe_reset_next(page, page2, lru);
+ nr_thp_split++;
goto retry;
}
}
+ if (is_thp) {
+ nr_thp_failed++;
+ nr_failed += nr_subpages;
+ goto out;
+ }
nr_failed++;
goto out;
case -EAGAIN:
+ if (is_thp) {
+ thp_retry++;
+ break;
+ }
retry++;
break;
case MIGRATEPAGE_SUCCESS:
+ if (is_thp) {
+ nr_thp_succeeded++;
+ nr_succeeded += nr_subpages;
+ break;
+ }
nr_succeeded++;
break;
default:
@@ -1482,19 +1510,27 @@ retry:
* removed from migration page list and not
* retried in the next outer loop.
*/
+ if (is_thp) {
+ nr_thp_failed++;
+ nr_failed += nr_subpages;
+ break;
+ }
nr_failed++;
break;
}
}
}
- nr_failed += retry;
+ nr_failed += retry + thp_retry;
+ nr_thp_failed += thp_retry;
rc = nr_failed;
out:
- if (nr_succeeded)
- count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded);
- if (nr_failed)
- count_vm_events(PGMIGRATE_FAIL, nr_failed);
- trace_mm_migrate_pages(nr_succeeded, nr_failed, mode, reason);
+ count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded);
+ count_vm_events(PGMIGRATE_FAIL, nr_failed);
+ 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, nr_thp_succeeded,
+ nr_thp_failed, nr_thp_split, mode, reason);
if (!swapwrite)
current->flags &= ~PF_SWAPWRITE;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 3bb034c99887..727a26d1ec1d 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1277,6 +1277,9 @@ const char * const vmstat_text[] = {
#ifdef CONFIG_MIGRATION
"pgmigrate_success",
"pgmigrate_fail",
+ "thp_migration_success",
+ "thp_migration_fail",
+ "thp_migration_split",
#endif
#ifdef CONFIG_COMPACTION
"compact_migrate_scanned",