Introduce a flag to restrict the selection of an idle CPU to a specific NUMA node. Signed-off-by: Andrea Righi <arighi@xxxxxxxxxx> --- kernel/sched/ext.c | 1 + kernel/sched/ext_idle.c | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 143938e935f1..da5c15bd3c56 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -773,6 +773,7 @@ enum scx_deq_flags { enum scx_pick_idle_cpu_flags { SCX_PICK_IDLE_CORE = 1LLU << 0, /* pick a CPU whose SMT siblings are also idle */ + SCX_PICK_IDLE_NODE = 1LLU << 1, /* pick a CPU in the same target NUMA node */ }; enum scx_kick_flags { diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index 444f2a15f1d4..013deaa08f12 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -199,6 +199,12 @@ static s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, int node, u64 f cpu = pick_idle_cpu_from_node(cpus_allowed, n, flags); if (cpu >= 0) break; + /* + * Check if the search is restricted to the same core or + * the same node. + */ + if (flags & SCX_PICK_IDLE_NODE) + break; } return cpu; @@ -495,7 +501,8 @@ static s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, * Search for any fully idle core in the same LLC domain. */ if (llc_cpus) { - cpu = pick_idle_cpu_from_node(llc_cpus, node, SCX_PICK_IDLE_CORE); + cpu = scx_pick_idle_cpu(llc_cpus, node, + SCX_PICK_IDLE_CORE | SCX_PICK_IDLE_NODE); if (cpu >= 0) goto cpu_found; } @@ -533,7 +540,7 @@ static s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, * Search for any idle CPU in the same LLC domain. */ if (llc_cpus) { - cpu = pick_idle_cpu_from_node(llc_cpus, node, 0); + cpu = scx_pick_idle_cpu(llc_cpus, node, SCX_PICK_IDLE_NODE); if (cpu >= 0) goto cpu_found; } -- 2.47.1