From: Biaoxiang Ye yebiaoxiang@huawei.com
euleros inclusion category: feature feature: Implement NUMA affinity for order workqueue
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Currently, single thread workqueue only have single pwq, all of works are queued the same workerpool. This is not optimal on NUMA machines, will cause workers jump around across node.
This patch add a new wq flags __WQ_DYNAMIC, this new kind of single thread workqueue creates a separate pwq covering the intersecting CPUS for each NUMA node which has online CPUS in @attrs->cpumask instead of mapping all entries of numa_pwq_tbl[] to the same pwq. After this, we can specify the @cpu of queue_work_on, so the work can be executed on the same NUMA node of the specified @cpu. This kind of wq only support single work, multi works can't guarantee the work's order.
Signed-off-by: Biaoxiang Ye yebiaoxiang@huawei.com Acked-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/workqueue.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index cdf9d95..118cf73 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3843,6 +3843,9 @@ static void apply_wqattrs_cleanup(struct apply_wqattrs_ctx *ctx) * wq_unbound_cpumask, we fallback to the wq_unbound_cpumask. */ copy_workqueue_attrs(new_attrs, attrs); + if (wq->flags & __WQ_DYNAMIC) + new_attrs->no_numa = false; + cpumask_and(new_attrs->cpumask, new_attrs->cpumask, wq_unbound_cpumask); if (unlikely(cpumask_empty(new_attrs->cpumask))) cpumask_copy(new_attrs->cpumask, wq_unbound_cpumask); @@ -4092,10 +4095,12 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) return 0; } else if (wq->flags & __WQ_ORDERED) { ret = apply_workqueue_attrs(wq, ordered_wq_attrs[highpri]); - /* there should only be single pwq for ordering guarantee */ - WARN(!ret && (wq->pwqs.next != &wq->dfl_pwq->pwqs_node || - wq->pwqs.prev != &wq->dfl_pwq->pwqs_node), - "ordering guarantee broken for workqueue %s\n", wq->name); + if (!(wq->flags & __WQ_DYNAMIC)) { + /* there should only be single pwq for ordering guarantee */ + WARN(!ret && (wq->pwqs.next != &wq->dfl_pwq->pwqs_node || + wq->pwqs.prev != &wq->dfl_pwq->pwqs_node), + "ordering guarantee broken for workqueue %s\n", wq->name); + } return ret; } else { return apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]); @@ -5166,7 +5171,7 @@ static int workqueue_apply_unbound_cpumask(void) if (!(wq->flags & WQ_UNBOUND)) continue; /* creating multiple pwqs breaks ordering guarantee */ - if (wq->flags & __WQ_ORDERED) + if ((wq->flags & __WQ_ORDERED) && !(wq->flags & __WQ_DYNAMIC)) continue;
ctx = apply_wqattrs_prepare(wq, wq->unbound_attrs);