diff options
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c47b38eded19..523b5aee2d6a 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7392,7 +7392,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) bool has_idle_core = false; struct sched_domain *sd; unsigned long task_util, util_min, util_max; - int i, recent_used_cpu; + int i, recent_used_cpu, prev_aff = -1; /* * On asymmetric system, update task utilization because we will check @@ -7424,6 +7424,8 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) if (!static_branch_unlikely(&sched_cluster_active) || cpus_share_resources(prev, target)) return prev; + + prev_aff = prev; } /* @@ -7456,6 +7458,8 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) cpus_share_resources(recent_used_cpu, target)) return recent_used_cpu; + } else { + recent_used_cpu = -1; } /* @@ -7496,6 +7500,17 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) if ((unsigned)i < nr_cpumask_bits) return i; + /* + * For cluster machines which have lower sharing cache like L2 or + * LLC Tag, we tend to find an idle CPU in the target's cluster + * first. But prev_cpu or recent_used_cpu may also be a good candidate, + * use them if possible when no idle CPU found in select_idle_cpu(). + */ + if ((unsigned int)prev_aff < nr_cpumask_bits) + return prev_aff; + if ((unsigned int)recent_used_cpu < nr_cpumask_bits) + return recent_used_cpu; + return target; } |