Re: WARNING in enqueue_task_dl

[syzbot]

syzbot has bisected this bug to:

commit 7c80cfc99b7bfdc92cee26f8008859f326f4a37f
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date:   Sat May 6 14:03:17 2017 +0000

    sched/fair: Clean up calc_cfs_shares()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=169d614d200000
start commit:   7c80cfc9 sched/fair: Clean up calc_cfs_shares()
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=159d614d200000
console output: https://syzkaller.appspot.com/x/log.txt?x=119d614d200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=76d28549be7c27cf
dashboard link: https://syzkaller.appspot.com/bug?extid=119ba87189432ead09b4
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10eb7ebf400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14156d77400000

Reported-by: syzbot+119ba87189432ead09b4@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 7c80cfc9 ("sched/fair: Clean up calc_cfs_shares()")