From 29cd8bae396583a2ee9a3340db8c5102acf9f6fd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 Sep 2009 09:01:14 +0200 Subject: [PATCH] sched: Fix SD_POWERSAVING_BALANCE|SD_PREFER_LOCAL vs SD_WAKE_AFFINE The SD_POWERSAVING_BALANCE|SD_PREFER_LOCAL code can break out of the domain iteration early, making us miss the SD_WAKE_AFFINE bits. Fix this by continuing iteration until there is no need for a larger domain. This also cleans up the cgroup stuff a bit, but not having two update_shares() invocations. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 42 +++++++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 15 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ffee827fa22f..10d218ab69f2 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1333,11 +1333,12 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) */ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) { - struct sched_domain *tmp, *shares = NULL, *sd = NULL; + struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); int new_cpu = cpu; int want_affine = 0; + int want_sd = 1; int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { @@ -1369,33 +1370,44 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag nr_running /= 2; if (nr_running < capacity) - break; + want_sd = 0; } if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { - if (sched_feat(LB_SHARES_UPDATE)) { - update_shares(tmp); - shares = tmp; - } - - if (wake_affine(tmp, p, sync)) { - new_cpu = cpu; - goto out; - } - + affine_sd = tmp; want_affine = 0; } + if (!want_sd && !want_affine) + break; + if (!(tmp->flags & sd_flag)) continue; - sd = tmp; + if (want_sd) + sd = tmp; + } + + if (sched_feat(LB_SHARES_UPDATE)) { + /* + * Pick the largest domain to update shares over + */ + tmp = sd; + if (affine_sd && (!tmp || + cpumask_weight(sched_domain_span(affine_sd)) > + cpumask_weight(sched_domain_span(sd)))) + tmp = affine_sd; + + if (tmp) + update_shares(tmp); } - if (sd && sd != shares && sched_feat(LB_SHARES_UPDATE)) - update_shares(sd); + if (affine_sd && wake_affine(affine_sd, p, sync)) { + new_cpu = cpu; + goto out; + } while (sd) { int load_idx = sd->forkexec_idx; -- 2.20.1