[patch v12 08/13] task isolation: enable return to userspace processing

[Marcelo Tosatti <mtosatti@redhat.com>]

Enable processing of pending task isolation work if per-CPU vmstats
are out of sync with global vmstats.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

---

v11:
   Fold patch to add task_isol_exit hooks into
  "sync vmstats on return to userspace" patch.          (Frederic W. Weisbecker)

 include/linux/task_isolation.h |   22 +++++++++++++++++++++-
 kernel/task_isolation.c        |   13 +++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

Index: linux-2.6/kernel/task_isolation.c
===================================================================
--- linux-2.6.orig/kernel/task_isolation.c
+++ linux-2.6/kernel/task_isolation.c
@@ -10,7 +10,6 @@
  */
 
 #include <linux/sched.h>
-#include <linux/task_isolation.h>
 #include <linux/prctl.h>
 #include <linux/slab.h>
 #include <linux/kobject.h>
@@ -20,9 +19,17 @@
 #include <linux/sched/task.h>
 #include <linux/mm.h>
 #include <linux/vmstat.h>
+#include <linux/task_isolation.h>
 
 void __task_isol_exit(struct task_struct *tsk)
 {
+	struct task_isol_info *i;
+
+	i = tsk->task_isol_info;
+	if (!i)
+		return;
+
+	static_key_slow_dec(&vmstat_sync_enabled);
 }
 
 void __task_isol_free(struct task_struct *tsk)
@@ -41,6 +48,12 @@ static struct task_isol_info *task_isol_
 	if (unlikely(!info))
 		return ERR_PTR(-ENOMEM);
 
+	preempt_disable();
+	init_sync_vmstat();
+	preempt_enable();
+
+	static_key_slow_inc(&vmstat_sync_enabled);
+
 	return info;
 }