[kbuild-all] Re: kernel/sched/fair.c:9551:12: warning: stack frame size of 1376 bytes in function 'load_balance'

On Tue, 11 May 2021 at 18:01, kernel test robot <lkp(a)intel.com&gt; wrote: It was a bit difficult to find the warning among the thousand This is triggered by the removal of code in update_sd/sg_lb_stats() which are in the call path of load_balance. load_balance find_busiest_group update_sd_lb_stats update_sg_lb_stats I don't expect the remove of code to increase the use of stack frame > ^ > 10 warnings generated. > > > vim +/load_balance +9551 kernel/sched/fair.c > > 23f0d2093c789e kernel/sched/fair.c Joonsoo Kim 2013-08-06 9546 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9547 /* > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9548 * Check this_cpu to ensure it is balanced within domain. Attempt to move > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9549 * tasks if there is an imbalance. > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9550 */ > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 @9551 static int load_balance(int this_cpu, struct rq *this_rq, > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9552 struct sched_domain *sd, enum cpu_idle_type idle, > 23f0d2093c789e kernel/sched/fair.c Joonsoo Kim 2013-08-06 9553 int *continue_balancing) > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9554 { > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9555 int ld_moved, cur_ld_moved, active_balance = 0; > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9556 struct sched_domain *sd_parent = sd->parent; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9557 struct sched_group *group; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9558 struct rq *busiest; > 8a8c69c3277886 kernel/sched/fair.c Peter Zijlstra 2016-10-04 9559 struct rq_flags rf; > 4ba2968420fa9d kernel/sched/fair.c Christoph Lameter 2014-08-26 9560 struct cpumask *cpus = this_cpu_cpumask_var_ptr(load_balance_mask); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9561 > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9562 struct lb_env env = { > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9563 .sd = sd, > ddcdf6e7d9919d kernel/sched/fair.c Peter Zijlstra 2012-02-22 9564 .dst_cpu = this_cpu, > ddcdf6e7d9919d kernel/sched/fair.c Peter Zijlstra 2012-02-22 9565 .dst_rq = this_rq, > ae4df9d6c93510 kernel/sched/fair.c Peter Zijlstra 2017-05-01 9566 .dst_grpmask = sched_group_span(sd->groups), > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9567 .idle = idle, > eb95308ee2a694 kernel/sched/fair.c Peter Zijlstra 2012-04-17 9568 .loop_break = sched_nr_migrate_break, > b9403130a5350f kernel/sched/fair.c Michael Wang 2012-07-12 9569 .cpus = cpus, > 0ec8aa00f2b4dc kernel/sched/fair.c Peter Zijlstra 2013-10-07 9570 .fbq_type = all, > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9571 .tasks = LIST_HEAD_INIT(env.tasks), > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9572 }; > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9573 > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9574 cpumask_and(cpus, sched_domain_span(sd), cpu_active_mask); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9575 > ae92882e5646d8 kernel/sched/fair.c Josh Poimboeuf 2016-06-17 9576 schedstat_inc(sd->lb_count[idle]); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9577 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9578 redo: > 23f0d2093c789e kernel/sched/fair.c Joonsoo Kim 2013-08-06 9579 if (!should_we_balance(&env)) { > 23f0d2093c789e kernel/sched/fair.c Joonsoo Kim 2013-08-06 9580 *continue_balancing = 0; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9581 goto out_balanced; > 23f0d2093c789e kernel/sched/fair.c Joonsoo Kim 2013-08-06 9582 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9583 > 23f0d2093c789e kernel/sched/fair.c Joonsoo Kim 2013-08-06 9584 group = find_busiest_group(&env); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9585 if (!group) { > ae92882e5646d8 kernel/sched/fair.c Josh Poimboeuf 2016-06-17 9586 schedstat_inc(sd->lb_nobusyg[idle]); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9587 goto out_balanced; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9588 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9589 > b9403130a5350f kernel/sched/fair.c Michael Wang 2012-07-12 9590 busiest = find_busiest_queue(&env, group); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9591 if (!busiest) { > ae92882e5646d8 kernel/sched/fair.c Josh Poimboeuf 2016-06-17 9592 schedstat_inc(sd->lb_nobusyq[idle]); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9593 goto out_balanced; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9594 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9595 > 78feefc512a091 kernel/sched/fair.c Michael Wang 2012-08-06 9596 BUG_ON(busiest == env.dst_rq); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9597 > ae92882e5646d8 kernel/sched/fair.c Josh Poimboeuf 2016-06-17 9598 schedstat_add(sd->lb_imbalance[idle], env.imbalance); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9599 > 1aaf90a4b88aae kernel/sched/fair.c Vincent Guittot 2015-02-27 9600 env.src_cpu = busiest->cpu; > 1aaf90a4b88aae kernel/sched/fair.c Vincent Guittot 2015-02-27 9601 env.src_rq = busiest; > 1aaf90a4b88aae kernel/sched/fair.c Vincent Guittot 2015-02-27 9602 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9603 ld_moved = 0; > 8a41dfcda7a32e kernel/sched/fair.c Vincent Guittot 2021-01-07 9604 /* Clear this flag as soon as we find a pullable task */ > 8a41dfcda7a32e kernel/sched/fair.c Vincent Guittot 2021-01-07 9605 env.flags |= LBF_ALL_PINNED; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9606 if (busiest->nr_running > 1) { > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9607 /* > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9608 * Attempt to move tasks. If find_busiest_group has found > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9609 * an imbalance but busiest->nr_running <= 1, the group is > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9610 * still unbalanced. ld_moved simply stays zero, so it is > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9611 * correctly treated as an imbalance. > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9612 */ > c82513e513556a kernel/sched/fair.c Peter Zijlstra 2012-04-26 9613 env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running); > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9614 > 5d6523ebd2f67d kernel/sched/fair.c Peter Zijlstra 2012-03-10 9615 more_balance: > 8a8c69c3277886 kernel/sched/fair.c Peter Zijlstra 2016-10-04 9616 rq_lock_irqsave(busiest, &rf); > 3bed5e2166a5e4 kernel/sched/fair.c Peter Zijlstra 2016-10-03 9617 update_rq_clock(busiest); > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9618 > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9619 /* > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9620 * cur_ld_moved - load moved in current iteration > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9621 * ld_moved - cumulative load moved across iterations > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9622 */ > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9623 cur_ld_moved = detach_tasks(&env); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9624 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9625 /* > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9626 * We've detached some tasks from busiest_rq. Every > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9627 * task is masked "TASK_ON_RQ_MIGRATING", so we can safely > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9628 * unlock busiest->lock, and we are able to be sure > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9629 * that nobody can manipulate the tasks in parallel. > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9630 * See task_rq_lock() family for the details. > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9631 */ > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9632 > 8a8c69c3277886 kernel/sched/fair.c Peter Zijlstra 2016-10-04 9633 rq_unlock(busiest, &rf); > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9634 > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9635 if (cur_ld_moved) { > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9636 attach_tasks(&env); > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9637 ld_moved += cur_ld_moved; > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9638 } > 163122b7fcfa28 kernel/sched/fair.c Kirill Tkhai 2014-08-20 9639 > 8a8c69c3277886 kernel/sched/fair.c Peter Zijlstra 2016-10-04 9640 local_irq_restore(rf.flags); > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9641 > f1cd0858100c67 kernel/sched/fair.c Joonsoo Kim 2013-04-23 9642 if (env.flags & LBF_NEED_BREAK) { > f1cd0858100c67 kernel/sched/fair.c Joonsoo Kim 2013-04-23 9643 env.flags &= ~LBF_NEED_BREAK; > f1cd0858100c67 kernel/sched/fair.c Joonsoo Kim 2013-04-23 9644 goto more_balance; > f1cd0858100c67 kernel/sched/fair.c Joonsoo Kim 2013-04-23 9645 } > f1cd0858100c67 kernel/sched/fair.c Joonsoo Kim 2013-04-23 9646 > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9647 /* > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9648 * Revisit (affine) tasks on src_cpu that couldn't be moved to > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9649 * us and move them to an alternate dst_cpu in our sched_group > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9650 * where they can run. The upper limit on how many times we > 97fb7a0a8944bd kernel/sched/fair.c Ingo Molnar 2018-03-03 9651 * iterate on same src_cpu is dependent on number of CPUs in our > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9652 * sched_group. > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9653 * > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9654 * This changes load balance semantics a bit on who can move > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9655 * load to a given_cpu. In addition to the given_cpu itself > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9656 * (or a ilb_cpu acting on its behalf where given_cpu is > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9657 * nohz-idle), we now have balance_cpu in a position to move > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9658 * load to given_cpu. In rare situations, this may cause > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9659 * conflicts (balance_cpu and given_cpu/ilb_cpu deciding > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9660 * _independently_ and at _same_ time to move some load to > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9661 * given_cpu) causing exceess load to be moved to given_cpu. > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9662 * This however should not happen so much in practice and > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9663 * moreover subsequent load balance cycles should correct the > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9664 * excess load moved. > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9665 */ > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9666 if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) { > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9667 > 97fb7a0a8944bd kernel/sched/fair.c Ingo Molnar 2018-03-03 9668 /* Prevent to re-select dst_cpu via env's CPUs */ > c89d92eddfad11 kernel/sched/fair.c Viresh Kumar 2019-02-12 9669 __cpumask_clear_cpu(env.dst_cpu, env.cpus); > 7aff2e3a56b724 kernel/sched/fair.c Vladimir Davydov 2013-09-15 9670 > 78feefc512a091 kernel/sched/fair.c Michael Wang 2012-08-06 9671 env.dst_rq = cpu_rq(env.new_dst_cpu); > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9672 env.dst_cpu = env.new_dst_cpu; > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9673 env.flags &= ~LBF_DST_PINNED; > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9674 env.loop = 0; > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9675 env.loop_break = sched_nr_migrate_break; > e02e60c109ca70 kernel/sched/fair.c Joonsoo Kim 2013-04-23 9676 > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9677 /* > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9678 * Go back to "more_balance" rather than "redo" since we > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9679 * need to continue with same src_cpu. > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9680 */ > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9681 goto more_balance; > 88b8dac0a14c51 kernel/sched/fair.c Srivatsa Vaddagiri 2012-06-19 9682 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9683 > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9684 /* > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9685 * We failed to reach balance because of affinity. > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9686 */ > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9687 if (sd_parent) { > 63b2ca30bdb3db kernel/sched/fair.c Nicolas Pitre 2014-05-26 9688 int *group_imbalance = &sd_parent->groups->sgc->imbalance; > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9689 > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9690 if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9691 *group_imbalance = 1; > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9692 } > 6263322c5e8ffd kernel/sched/fair.c Peter Zijlstra 2013-08-19 9693 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9694 /* All tasks on this runqueue were pinned by CPU affinity */ > 8e45cb545d98bc kernel/sched/fair.c Peter Zijlstra 2012-02-22 9695 if (unlikely(env.flags & LBF_ALL_PINNED)) { > c89d92eddfad11 kernel/sched/fair.c Viresh Kumar 2019-02-12 9696 __cpumask_clear_cpu(cpu_of(busiest), cpus); > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9697 /* > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9698 * Attempting to continue load balancing at the current > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9699 * sched_domain level only makes sense if there are > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9700 * active CPUs remaining as possible busiest CPUs to > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9701 * pull load from which are not contained within the > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9702 * destination group that is receiving any migrated > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9703 * load. > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9704 */ > 65a4433aebe36c kernel/sched/fair.c Jeffrey Hugo 2017-06-07 9705 if (!cpumask_subset(cpus, env.dst_grpmask)) { > bbf18b19495942 kernel/sched/fair.c Prashanth Nageshappa 2012-06-19 9706 env.loop = 0; > bbf18b19495942 kernel/sched/fair.c Prashanth Nageshappa 2012-06-19 9707 env.loop_break = sched_nr_migrate_break; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9708 goto redo; > bbf18b19495942 kernel/sched/fair.c Prashanth Nageshappa 2012-06-19 9709 } > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9710 goto out_all_pinned; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9711 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9712 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9713 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9714 if (!ld_moved) { > ae92882e5646d8 kernel/sched/fair.c Josh Poimboeuf 2016-06-17 9715 schedstat_inc(sd->lb_failed[idle]); > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9716 /* > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9717 * Increment the failure counter only on periodic balance. > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9718 * We do not want newidle balance, which can be very > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9719 * frequent, pollute the failure counter causing > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9720 * excessive cache_hot migrations and active balances. > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9721 */ > 58b26c4c025778 kernel/sched_fair.c Venkatesh Pallipadi 2010-09-10 9722 if (idle != CPU_NEWLY_IDLE) > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9723 sd->nr_balance_failed++; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9724 > bd939f45da24e2 kernel/sched/fair.c Peter Zijlstra 2012-05-02 9725 if (need_active_balance(&env)) { > 8a8c69c3277886 kernel/sched/fair.c Peter Zijlstra 2016-10-04 9726 unsigned long flags; > 8a8c69c3277886 kernel/sched/fair.c Peter Zijlstra 2016-10-04 9727 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9728 raw_spin_lock_irqsave(&busiest->lock, flags); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9729 > 97fb7a0a8944bd kernel/sched/fair.c Ingo Molnar 2018-03-03 9730 /* > 97fb7a0a8944bd kernel/sched/fair.c Ingo Molnar 2018-03-03 9731 * Don't kick the active_load_balance_cpu_stop, > 97fb7a0a8944bd kernel/sched/fair.c Ingo Molnar 2018-03-03 9732 * if the curr task on busiest CPU can't be > 97fb7a0a8944bd kernel/sched/fair.c Ingo Molnar 2018-03-03 9733 * moved to this_cpu: > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9734 */ > 3bd3706251ee8a kernel/sched/fair.c Sebastian Andrzej Siewior 2019-04-23 9735 if (!cpumask_test_cpu(this_cpu, busiest->curr->cpus_ptr)) { > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9736 raw_spin_unlock_irqrestore(&busiest->lock, > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9737 flags); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9738 goto out_one_pinned; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9739 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9740 > 8a41dfcda7a32e kernel/sched/fair.c Vincent Guittot 2021-01-07 9741 /* Record that we found at least one task that could run on this_cpu */ > 8a41dfcda7a32e kernel/sched/fair.c Vincent Guittot 2021-01-07 9742 env.flags &= ~LBF_ALL_PINNED; > 8a41dfcda7a32e kernel/sched/fair.c Vincent Guittot 2021-01-07 9743 > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9744 /* > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9745 * ->active_balance synchronizes accesses to > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9746 * ->active_balance_work. Once set, it's cleared > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9747 * only after active load balance is finished. > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9748 */ > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9749 if (!busiest->active_balance) { > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9750 busiest->active_balance = 1; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9751 busiest->push_cpu = this_cpu; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9752 active_balance = 1; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9753 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9754 raw_spin_unlock_irqrestore(&busiest->lock, flags); > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9755 > bd939f45da24e2 kernel/sched/fair.c Peter Zijlstra 2012-05-02 9756 if (active_balance) { > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9757 stop_one_cpu_nowait(cpu_of(busiest), > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9758 active_load_balance_cpu_stop, busiest, > 969c79215a35b0 kernel/sched_fair.c Tejun Heo 2010-05-06 9759 &busiest->active_balance_work); > bd939f45da24e2 kernel/sched/fair.c Peter Zijlstra 2012-05-02 9760 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9761 > d02c071183e1c0 kernel/sched/fair.c Srikar Dronamraju 2016-03-23 9762 /* We've kicked active balancing, force task migration. */ > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9763 sd->nr_balance_failed = sd->cache_nice_tries+1; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9764 } > e9b9734b74656a kernel/sched/fair.c Vincent Guittot 2021-01-07 9765 } else { > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9766 sd->nr_balance_failed = 0; > e9b9734b74656a kernel/sched/fair.c Vincent Guittot 2021-01-07 9767 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9768 > e9b9734b74656a kernel/sched/fair.c Vincent Guittot 2021-01-07 9769 if (likely(!active_balance) || need_active_balance(&env)) { > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9770 /* We were unbalanced, so reset the balancing interval */ > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9771 sd->balance_interval = sd->min_interval; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9772 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9773 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9774 goto out; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9775 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9776 out_balanced: > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9777 /* > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9778 * We reach balance although we may have faced some affinity > f6cad8df6b30a5 kernel/sched/fair.c Vincent Guittot 2019-07-01 9779 * constraints. Clear the imbalance flag only if other tasks got > f6cad8df6b30a5 kernel/sched/fair.c Vincent Guittot 2019-07-01 9780 * a chance to move and fix the imbalance. > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9781 */ > f6cad8df6b30a5 kernel/sched/fair.c Vincent Guittot 2019-07-01 9782 if (sd_parent && !(env.flags & LBF_ALL_PINNED)) { > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9783 int *group_imbalance = &sd_parent->groups->sgc->imbalance; > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9784 > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9785 if (*group_imbalance) > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9786 *group_imbalance = 0; > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9787 } > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9788 > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9789 out_all_pinned: > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9790 /* > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9791 * We reach balance because all tasks are pinned at this level so > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9792 * we can't migrate them. Let the imbalance flag set so parent level > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9793 * can try to migrate them. > afdeee0510db91 kernel/sched/fair.c Vincent Guittot 2014-08-26 9794 */ > ae92882e5646d8 kernel/sched/fair.c Josh Poimboeuf 2016-06-17 9795 schedstat_inc(sd->lb_balanced[idle]); > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9796 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9797 sd->nr_balance_failed = 0; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9798 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9799 out_one_pinned: > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9800 ld_moved = 0; > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9801 > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9802 /* > 5ba553eff0c3a7 kernel/sched/fair.c Peter Zijlstra 2019-05-29 9803 * newidle_balance() disregards balance intervals, so we could > 5ba553eff0c3a7 kernel/sched/fair.c Peter Zijlstra 2019-05-29 9804 * repeatedly reach this code, which would lead to balance_interval > 5ba553eff0c3a7 kernel/sched/fair.c Peter Zijlstra 2019-05-29 9805 * skyrocketting in a short amount of time. Skip the balance_interval > 5ba553eff0c3a7 kernel/sched/fair.c Peter Zijlstra 2019-05-29 9806 * increase logic to avoid that. > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9807 */ > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9808 if (env.idle == CPU_NEWLY_IDLE) > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9809 goto out; > 3f130a37c442d5 kernel/sched/fair.c Valentin Schneider 2018-09-26 9810 > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9811 /* tune up the balancing interval */ > 47b7aee14fd7e4 kernel/sched/fair.c Valentin Schneider 2018-09-26 9812 if ((env.flags & LBF_ALL_PINNED && > 5b54b56be5b540 kernel/sched/fair.c Peter Zijlstra 2011-09-22 9813 sd->balance_interval < MAX_PINNED_INTERVAL) || > 47b7aee14fd7e4 kernel/sched/fair.c Valentin Schneider 2018-09-26 9814 sd->balance_interval < sd->max_interval) > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9815 sd->balance_interval *= 2; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9816 out: > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9817 return ld_moved; > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9818 } > 1e3c88bdeb1260 kernel/sched_fair.c Peter Zijlstra 2009-12-17 9819 > > :::::: The code at line 9551 was first introduced by commit > :::::: 1e3c88bdeb1260edc341e45c9fb8efd182a5c511 sched: Move load balance code into sched_fair.c > > :::::: TO: Peter Zijlstra <a.p.zijlstra(a)chello.nl&gt; > :::::: CC: Ingo Molnar <mingo(a)elte.hu&gt; > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org