Messages in this thread Patch in this message | | | From | Viresh Kumar <> | Subject | [PATCH] sched/fair: Rearrange select_task_rq_fair() to optimize it | Date | Mon, 23 Apr 2018 16:08:26 +0530 |
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Rearrange select_task_rq_fair() a bit to avoid executing some conditional statements in few specific code-paths. That gets rid of the goto as well.
This shouldn't result in any functional changes.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- kernel/sched/fair.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 54dc31e7ab9b..cacee15076a4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6636,6 +6636,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f */ if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { + sd = NULL; /* Prefer wake_affine over balance flags */ affine_sd = tmp; break; } @@ -6646,33 +6647,26 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f break; } - if (affine_sd) { - sd = NULL; /* Prefer wake_affine over balance flags */ - if (cpu == prev_cpu) - goto pick_cpu; - - new_cpu = wake_affine(affine_sd, p, cpu, prev_cpu, sync); - } - - if (sd && !(sd_flag & SD_BALANCE_FORK)) { + if (sd) { /* * We're going to need the task's util for capacity_spare_wake * in find_idlest_group. Sync it up to prev_cpu's * last_update_time. */ - sync_entity_load_avg(&p->se); - } + if (!(sd_flag & SD_BALANCE_FORK)) + sync_entity_load_avg(&p->se); + + new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag); + } else { + if (affine_sd && cpu != prev_cpu) + new_cpu = wake_affine(affine_sd, p, cpu, prev_cpu, sync); - if (!sd) { -pick_cpu: if (sd_flag & SD_BALANCE_WAKE) { /* XXX always ? */ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu); if (want_affine) current->recent_used_cpu = cpu; } - } else { - new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag); } rcu_read_unlock(); -- 2.15.0.194.g9af6a3dea062
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