contest: vm: sleep 5 sec before triggering kmemleak

Stan reports that kmemleak has a 5 sec grace period.
This is probably also why we always catch leaks on the second scan.
Add a sleep.

Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

contest/remote/lib/vm.py

@@ -402,6 +402,9 @@ def check_health(self):
         if self.fail_state:
             return
         if self.has_kmemleak:
+            # kmemleak needs objects to be at least MSECS_MIN_AGE (5000)
+            # before it considers them to have been leaked
+            sleep(5)
             self.cmd("echo scan > /sys/kernel/debug/kmemleak && cat /sys/kernel/debug/kmemleak")
             self.drain_to_prompt()
             # Do it twice, kmemleak likes to hide the leak on the first attempt