It is for a debug purpose and is called when a vmap area
gets freed. This event gives some indication about:
- a start address of released area;
- a current number of outstanding pages;
- a maximum number of allowed outstanding pages.
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
mm/vmalloc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 912abcd6e8b4..df4fd6674ced 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1822,6 +1822,8 @@ static void drain_vmap_area_work(struct work_struct *work)
*/
static void free_vmap_area_noflush(struct vmap_area *va)
{
+ unsigned long nr_lazy_max = lazy_max_pages();
+ unsigned long va_start = va->va_start;
unsigned long nr_lazy;
spin_lock(&vmap_area_lock);
@@ -1839,8 +1841,10 @@ static void free_vmap_area_noflush(struct vmap_area *va)
&purge_vmap_area_root, &purge_vmap_area_list);
spin_unlock(&purge_vmap_area_lock);
+ trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max);
+
/* After this point, we may free va at any time */
- if (unlikely(nr_lazy > lazy_max_pages()))
+ if (unlikely(nr_lazy > nr_lazy_max))
schedule_work(&drain_vmap_work);
}
--
2.30.2
