Merge branch 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux.git] / kernel / sched / psi.c

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 23fbbcc414d5d739507ac1f8ecb5757c87a9ce55..517e3719027e619e5c7b565d1de9294dfffb5a3c 100644 (file)
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1131,7 +1131,15 @@ static void psi_trigger_destroy(struct kref *ref)
         * deadlock while waiting for psi_poll_work to acquire trigger_lock
         */
        if (kworker_to_destroy) {
+               /*
+                * After the RCU grace period has expired, the worker
+                * can no longer be found through group->poll_kworker.
+                * But it might have been already scheduled before
+                * that - deschedule it cleanly before destroying it.
+                */
                kthread_cancel_delayed_work_sync(&group->poll_work);
+               atomic_set(&group->poll_scheduled, 0);
+
                kthread_destroy_worker(kworker_to_destroy);
        }
        kfree(t);
@@ -1190,7 +1198,7 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf,
        if (static_branch_likely(&psi_disabled))
                return -EOPNOTSUPP;
 
-       buf_size = min(nbytes, (sizeof(buf) - 1));
+       buf_size = min(nbytes, sizeof(buf));
        if (copy_from_user(buf, user_buf, buf_size))
                return -EFAULT;