Hi Peter, [FYI, it's a private test report for your RFC patch.] [auto build test ERROR on tip/locking/core] [cannot apply to tip/sched/core kselftest/next tip/auto-latest v5.8-rc1 next-20200615] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Peter-Oskolkov/futex-sched-intro... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 19f545b6e07f753c4dc639c2f0ab52345733b6a8 config: microblaze-randconfig-c022-20200616 (attached as .config) compiler: microblaze-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>, old ones prefixed by <<): microblaze-linux-ld: kernel/futex.o: in function `futex_wait_queue_me': vim +2649 kernel/futex.c 2611 2612 /** 2613 * futex_wait_queue_me() - queue_me() and wait for wakeup, timeout, or signal 2614 * @hb: the futex hash bucket, must be locked by the caller 2615 * @q: the futex_q to queue up on 2616 * @timeout: the prepared hrtimer_sleeper, or null for no timeout 2617 * @next: if present, wake next and hint to the scheduler that we'd 2618 * prefer to execute it locally. 2619 */ 2620 static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, 2621 struct hrtimer_sleeper *timeout, 2622 struct task_struct *next) 2623 { 2624 /* 2625 * The task state is guaranteed to be set before another task can 2626 * wake it. set_current_state() is implemented using smp_store_mb() and 2627 * queue_me() calls spin_unlock() upon completion, both serializing 2628 * access to the hash list and forcing another memory barrier. 2629 */ 2630 set_current_state(TASK_INTERRUPTIBLE); 2631 queue_me(q, hb); 2632 2633 /* Arm the timer */ 2634 if (timeout) 2635 hrtimer_sleeper_start_expires(timeout, HRTIMER_MODE_ABS); 2636 2637 /* 2638 * If we have been removed from the hash list, then another task 2639 * has tried to wake us, and we can skip the call to schedule(). 2640 */ 2641 if (likely(!plist_node_empty(&q->list))) { 2642 /* 2643 * If the timer has already expired, current will already be 2644 * flagged for rescheduling. Only call schedule if there 2645 * is no timeout, or if it has yet to expire. 2646 */ 2647 if (!timeout || timeout->task) { 2648 if (next) { 2650 put_task_struct(next); 2651 next = NULL; 2652 } 2653 freezable_schedule(); 2654 } 2655 } 2656 __set_current_state(TASK_RUNNING); 2657 2658 if (next) { 2659 /* Maybe call wake_up_process_prefer_current_cpu()? */ 2660 wake_up_process(next); 2661 put_task_struct(next); 2662 } 2663 } 2664 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org