mm: migrate: Add a tracepoint for migrate_pages

The pgmigrate_success and pgmigrate_fail vmstat counters tells the user
about migration activity but not the type or the reason. This patch adds
a tracepoint to identify the type of page migration and why the page is
being migrated.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 04687f69cc17..27be9c923dc1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -38,6 +38,9 @@
 
 #include <asm/tlbflush.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/migrate.h>
+
 #include "internal.h"
 
 /*
@@ -958,7 +961,7 @@ out:
  */
 int migrate_pages(struct list_head *from,
                 new_page_t get_new_page, unsigned long private, bool offlining,
-                enum migrate_mode mode)
+                enum migrate_mode mode, int reason)
 {
         int retry = 1;
         int nr_failed = 0;
@@ -1004,6 +1007,8 @@ out:
                 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);
+
         if (!swapwrite)
                 current->flags &= ~PF_SWAPWRITE;
 
@@ -1145,7 +1150,8 @@ set_status:
         err = 0;
         if (!list_empty(&pagelist)) {
                 err = migrate_pages(&pagelist, new_page_node,
-                                (unsigned long)pm, 0, MIGRATE_SYNC);
+                                (unsigned long)pm, 0, MIGRATE_SYNC,
+                                MR_SYSCALL);
                 if (err)
                         putback_lru_pages(&pagelist);
         }