Hi Huaixin, Thank you for the patch! Yet something to improve: [auto build test ERROR on tip/sched/core] [also build test ERROR on tip/master linus/master v5.10 next-20201217] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Huaixin-Chang/sched-fair-Burstable-CFS-bandwidth-controller/20201217-155214 base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 5b78f2dc315354c05300795064f587366a02c6ff config: i386-randconfig-r013-20200812 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/d2f5cde464c872307ee33f78ba167a6f3334697c git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Huaixin-Chang/sched-fair-Burstable-CFS-bandwidth-controller/20201217-155214 git checkout d2f5cde464c872307ee33f78ba167a6f3334697c # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): ld: kernel/sched/core.o: in function `tg_set_cfs_bandwidth': >> kernel/sched/core.c:8596: undefined reference to `__udivdi3' vim +8596 kernel/sched/core.c 8521 8522 static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota, 8523 u64 burst) 8524 { 8525 int i, ret = 0, runtime_enabled, runtime_was_enabled; 8526 struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; 8527 u64 buffer, burst_onset; 8528 8529 if (tg == &root_task_group) 8530 return -EINVAL; 8531 8532 /* 8533 * Ensure we have at some amount of bandwidth every period. This is 8534 * to prevent reaching a state of large arrears when throttled via 8535 * entity_tick() resulting in prolonged exit starvation. 8536 */ 8537 if (quota < min_cfs_quota_period || period < min_cfs_quota_period) 8538 return -EINVAL; 8539 8540 /* 8541 * Likewise, bound things on the otherside by preventing insane quota 8542 * periods. This also allows us to normalize in computing quota 8543 * feasibility. 8544 */ 8545 if (period > max_cfs_quota_period) 8546 return -EINVAL; 8547 8548 /* 8549 * Bound quota to defend quota against overflow during bandwidth shift. 8550 */ 8551 if (quota != RUNTIME_INF && quota > max_cfs_runtime) 8552 return -EINVAL; 8553 8554 /* 8555 * Bound burst to defend burst against overflow during bandwidth shift. 8556 */ 8557 if (burst > max_cfs_runtime) 8558 return -EINVAL; 8559 8560 if (quota == RUNTIME_INF) 8561 buffer = RUNTIME_INF; 8562 else 8563 buffer = min(max_cfs_runtime, quota + burst); 8564 /* 8565 * Prevent race between setting of cfs_rq->runtime_enabled and 8566 * unthrottle_offline_cfs_rqs(). 8567 */ 8568 get_online_cpus(); 8569 mutex_lock(&cfs_constraints_mutex); 8570 ret = __cfs_schedulable(tg, period, quota); 8571 if (ret) 8572 goto out_unlock; 8573 8574 runtime_enabled = quota != RUNTIME_INF; 8575 runtime_was_enabled = cfs_b->quota != RUNTIME_INF; 8576 /* 8577 * If we need to toggle cfs_bandwidth_used, off->on must occur 8578 * before making related changes, and on->off must occur afterwards 8579 */ 8580 if (runtime_enabled && !runtime_was_enabled) 8581 cfs_bandwidth_usage_inc(); 8582 raw_spin_lock_irq(&cfs_b->lock); 8583 cfs_b->period = ns_to_ktime(period); 8584 cfs_b->quota = quota; 8585 cfs_b->burst = burst; 8586 cfs_b->buffer = buffer; 8587 8588 cfs_b->max_overrun = DIV_ROUND_UP_ULL(max_cfs_runtime, quota); 8589 cfs_b->runtime = cfs_b->quota; 8590 8591 /* burst_onset needed */ 8592 if (cfs_b->quota != RUNTIME_INF && 8593 sysctl_sched_cfs_bw_burst_enabled && 8594 sysctl_sched_cfs_bw_burst_onset_percent > 0) { 8595 > 8596 burst_onset = burst / 100 * 8597 sysctl_sched_cfs_bw_burst_onset_percent; 8598 8599 cfs_b->runtime += burst_onset; 8600 cfs_b->runtime = min(max_cfs_runtime, cfs_b->runtime); 8601 } 8602 8603 /* Restart the period timer (if active) to handle new period expiry: */ 8604 if (runtime_enabled) 8605 start_cfs_bandwidth(cfs_b, 1); 8606 8607 raw_spin_unlock_irq(&cfs_b->lock); 8608 8609 for_each_online_cpu(i) { 8610 struct cfs_rq *cfs_rq = tg->cfs_rq[i]; 8611 struct rq *rq = cfs_rq->rq; 8612 struct rq_flags rf; 8613 8614 rq_lock_irq(rq, &rf); 8615 cfs_rq->runtime_enabled = runtime_enabled; 8616 cfs_rq->runtime_remaining = 0; 8617 8618 if (cfs_rq->throttled) 8619 unthrottle_cfs_rq(cfs_rq); 8620 rq_unlock_irq(rq, &rf); 8621 } 8622 if (runtime_was_enabled && !runtime_enabled) 8623 cfs_bandwidth_usage_dec(); 8624 out_unlock: 8625 mutex_unlock(&cfs_constraints_mutex); 8626 put_online_cpus(); 8627 8628 return ret; 8629 } 8630 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org