From: Jack Morgenstein Date: Mon, 27 Aug 2018 05:35:55 +0000 (+0300) Subject: IB/core: Add an unbound WQ type to the new CQ API X-Git-Tag: v4.20-rc1~110^2~214 X-Git-Url: https://git.kernel.dk/?p=linux-2.6-block.git;a=commitdiff_plain;h=f794809a7259dfaa3d47d90ef5a86007cf48b1ce IB/core: Add an unbound WQ type to the new CQ API The upstream kernel commit cited below modified the workqueue in the new CQ API to be bound to a specific CPU (instead of being unbound). This caused ALL users of the new CQ API to use the same bound WQ. Specifically, MAD handling was severely delayed when the CPU bound to the WQ was busy handling (higher priority) interrupts. This caused a delay in the MAD "heartbeat" response handling, which resulted in ports being incorrectly classified as "down". To fix this, add a new "unbound" WQ type to the new CQ API, so that users have the option to choose either a bound WQ or an unbound WQ. For MADs, choose the new "unbound" WQ. Fixes: b7363e67b23e ("IB/device: Convert ib-comp-wq to be CPU-bound") Signed-off-by: Jack Morgenstein Signed-off-by: Leon Romanovsky Reviewed-by: Sagi Grimberg Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c index af5ad6a56ae4..9271f7290005 100644 --- a/drivers/infiniband/core/cq.c +++ b/drivers/infiniband/core/cq.c @@ -112,12 +112,12 @@ static void ib_cq_poll_work(struct work_struct *work) IB_POLL_BATCH); if (completed >= IB_POLL_BUDGET_WORKQUEUE || ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) - queue_work(ib_comp_wq, &cq->work); + queue_work(cq->comp_wq, &cq->work); } static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private) { - queue_work(ib_comp_wq, &cq->work); + queue_work(cq->comp_wq, &cq->work); } /** @@ -175,9 +175,12 @@ struct ib_cq *__ib_alloc_cq(struct ib_device *dev, void *private, ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); break; case IB_POLL_WORKQUEUE: + case IB_POLL_UNBOUND_WORKQUEUE: cq->comp_handler = ib_cq_completion_workqueue; INIT_WORK(&cq->work, ib_cq_poll_work); ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); + cq->comp_wq = (cq->poll_ctx == IB_POLL_WORKQUEUE) ? + ib_comp_wq : ib_comp_unbound_wq; break; default: ret = -EINVAL; @@ -213,6 +216,7 @@ void ib_free_cq(struct ib_cq *cq) irq_poll_disable(&cq->iop); break; case IB_POLL_WORKQUEUE: + case IB_POLL_UNBOUND_WORKQUEUE: cancel_work_sync(&cq->work); break; default: diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index db3b6271f09d..6d8ac51a39cc 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -61,6 +61,7 @@ struct ib_client_data { }; struct workqueue_struct *ib_comp_wq; +struct workqueue_struct *ib_comp_unbound_wq; struct workqueue_struct *ib_wq; EXPORT_SYMBOL_GPL(ib_wq); @@ -1166,10 +1167,19 @@ static int __init ib_core_init(void) goto err; } + ib_comp_unbound_wq = + alloc_workqueue("ib-comp-unb-wq", + WQ_UNBOUND | WQ_HIGHPRI | WQ_MEM_RECLAIM | + WQ_SYSFS, WQ_UNBOUND_MAX_ACTIVE); + if (!ib_comp_unbound_wq) { + ret = -ENOMEM; + goto err_comp; + } + ret = class_register(&ib_class); if (ret) { pr_warn("Couldn't create InfiniBand device class\n"); - goto err_comp; + goto err_comp_unbound; } ret = rdma_nl_init(); @@ -1218,6 +1228,8 @@ err_ibnl: rdma_nl_exit(); err_sysfs: class_unregister(&ib_class); +err_comp_unbound: + destroy_workqueue(ib_comp_unbound_wq); err_comp: destroy_workqueue(ib_comp_wq); err: @@ -1236,6 +1248,7 @@ static void __exit ib_core_cleanup(void) addr_cleanup(); rdma_nl_exit(); class_unregister(&ib_class); + destroy_workqueue(ib_comp_unbound_wq); destroy_workqueue(ib_comp_wq); /* Make sure that any pending umem accounting work is done. */ destroy_workqueue(ib_wq); diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c index ef459f2f2eeb..b8977c3db5f3 100644 --- a/drivers/infiniband/core/mad.c +++ b/drivers/infiniband/core/mad.c @@ -3183,7 +3183,7 @@ static int ib_mad_port_open(struct ib_device *device, cq_size *= 2; port_priv->cq = ib_alloc_cq(port_priv->device, port_priv, cq_size, 0, - IB_POLL_WORKQUEUE); + IB_POLL_UNBOUND_WORKQUEUE); if (IS_ERR(port_priv->cq)) { dev_err(&device->dev, "Couldn't create ib_mad CQ\n"); ret = PTR_ERR(port_priv->cq); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index e950c2a68f06..df8d234a2b56 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -71,6 +71,7 @@ extern struct workqueue_struct *ib_wq; extern struct workqueue_struct *ib_comp_wq; +extern struct workqueue_struct *ib_comp_unbound_wq; union ib_gid { u8 raw[16]; @@ -1570,9 +1571,10 @@ struct ib_ah { typedef void (*ib_comp_handler)(struct ib_cq *cq, void *cq_context); enum ib_poll_context { - IB_POLL_DIRECT, /* caller context, no hw completions */ - IB_POLL_SOFTIRQ, /* poll from softirq context */ - IB_POLL_WORKQUEUE, /* poll from workqueue */ + IB_POLL_DIRECT, /* caller context, no hw completions */ + IB_POLL_SOFTIRQ, /* poll from softirq context */ + IB_POLL_WORKQUEUE, /* poll from workqueue */ + IB_POLL_UNBOUND_WORKQUEUE, /* poll from unbound workqueue */ }; struct ib_cq { @@ -1589,6 +1591,7 @@ struct ib_cq { struct irq_poll iop; struct work_struct work; }; + struct workqueue_struct *comp_wq; /* * Implementation details of the RDMA core, don't use in drivers: */