softlockup: remove timestamp checking from hung_task
Impact: saves sizeof(long) bytes per task_struct
By guaranteeing that sysctl_hung_task_timeout_secs have elapsed between
tasklist scans we can avoid using timestamps.
Signed-off-by: Mandeep Singh Baines <msb@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/fork.c b/kernel/fork.c
index fb94442..bf582f7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -639,6 +639,9 @@
tsk->min_flt = tsk->maj_flt = 0;
tsk->nvcsw = tsk->nivcsw = 0;
+#ifdef CONFIG_DETECT_HUNG_TASK
+ tsk->last_switch_count = tsk->nvcsw + tsk->nivcsw;
+#endif
tsk->mm = NULL;
tsk->active_mm = NULL;
@@ -1041,11 +1044,6 @@
p->default_timer_slack_ns = current->timer_slack_ns;
-#ifdef CONFIG_DETECT_HUNG_TASK
- p->last_switch_count = 0;
- p->last_switch_timestamp = 0;
-#endif
-
task_io_accounting_init(&p->ioac);
acct_clear_integrals(p);