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authorSebastian Sanchez <sebastian.sanchez@intel.com>2018-05-02 16:43:55 +0300
committerDoug Ledford <dledford@redhat.com>2018-05-09 22:53:30 +0300
commit5d18ee67d4c1735f5c1f757e89228ec68e4f4ef3 (patch)
treebee1ad21ecea953b9048b94fd05b2c86a4128c27 /drivers/infiniband/sw/rdmavt/cq.c
parentcf38ea100edfcc0ec0a5797966d69ec4e10fe4f1 (diff)
downloadlinux-5d18ee67d4c1735f5c1f757e89228ec68e4f4ef3.tar.xz
IB/{hfi1, rdmavt, qib}: Implement CQ completion vector support
Currently the driver doesn't support completion vectors. These are used to indicate which sets of CQs should be grouped together into the same vector. A vector is a CQ processing thread that runs on a specific CPU. If an application has several CQs bound to different completion vectors, and each completion vector runs on different CPUs, then the completion queue workload is balanced. This helps scale as more nodes are used. Implement CQ completion vector support using a global workqueue where a CQ entry is queued to the CPU corresponding to the CQ's completion vector. Since the workqueue is global, it's guaranteed to always be there when queueing CQ entries; Therefore, the RCU locking for cq->rdi->worker in the hot path is superfluous. Each completion vector is assigned to a different CPU. The number of completion vectors available is computed by taking the number of online, physical CPUs from the local NUMA node and subtracting the CPUs used for kernel receive queues and the general interrupt. Special use cases: * If there are no CPUs left for completion vectors, the same CPU for the general interrupt is used; Therefore, there would only be one completion vector available. * For multi-HFI systems, the number of completion vectors available for each device is the total number of completion vectors in the local NUMA node divided by the number of devices in the same NUMA node. If there's a division remainder, the first device to get initialized gets an extra completion vector. Upon a CQ creation, an invalid completion vector could be specified. Handle it as follows: * If the completion vector is less than 0, set it to 0. * Set the completion vector to the result of the passed completion vector moded with the number of device completion vectors available. Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/sw/rdmavt/cq.c')
-rw-r--r--drivers/infiniband/sw/rdmavt/cq.c81
1 files changed, 32 insertions, 49 deletions
diff --git a/drivers/infiniband/sw/rdmavt/cq.c b/drivers/infiniband/sw/rdmavt/cq.c
index 340c17aba3b0..4f1544ad4aff 100644
--- a/drivers/infiniband/sw/rdmavt/cq.c
+++ b/drivers/infiniband/sw/rdmavt/cq.c
@@ -1,5 +1,5 @@
/*
- * Copyright(c) 2016 Intel Corporation.
+ * Copyright(c) 2016 - 2018 Intel Corporation.
*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
@@ -47,11 +47,12 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
-#include <linux/kthread.h>
#include "cq.h"
#include "vt.h"
#include "trace.h"
+static struct workqueue_struct *comp_vector_wq;
+
/**
* rvt_cq_enter - add a new entry to the completion queue
* @cq: completion queue
@@ -120,27 +121,21 @@ void rvt_cq_enter(struct rvt_cq *cq, struct ib_wc *entry, bool solicited)
if (cq->notify == IB_CQ_NEXT_COMP ||
(cq->notify == IB_CQ_SOLICITED &&
(solicited || entry->status != IB_WC_SUCCESS))) {
- struct kthread_worker *worker;
-
/*
* This will cause send_complete() to be called in
* another thread.
*/
- rcu_read_lock();
- worker = rcu_dereference(cq->rdi->worker);
- if (likely(worker)) {
- cq->notify = RVT_CQ_NONE;
- cq->triggered++;
- kthread_queue_work(worker, &cq->comptask);
- }
- rcu_read_unlock();
+ cq->notify = RVT_CQ_NONE;
+ cq->triggered++;
+ queue_work_on(cq->comp_vector_cpu, comp_vector_wq,
+ &cq->comptask);
}
spin_unlock_irqrestore(&cq->lock, flags);
}
EXPORT_SYMBOL(rvt_cq_enter);
-static void send_complete(struct kthread_work *work)
+static void send_complete(struct work_struct *work)
{
struct rvt_cq *cq = container_of(work, struct rvt_cq, comptask);
@@ -192,6 +187,7 @@ struct ib_cq *rvt_create_cq(struct ib_device *ibdev,
struct ib_cq *ret;
u32 sz;
unsigned int entries = attr->cqe;
+ int comp_vector = attr->comp_vector;
if (attr->flags)
return ERR_PTR(-EINVAL);
@@ -199,6 +195,11 @@ struct ib_cq *rvt_create_cq(struct ib_device *ibdev,
if (entries < 1 || entries > rdi->dparms.props.max_cqe)
return ERR_PTR(-EINVAL);
+ if (comp_vector < 0)
+ comp_vector = 0;
+
+ comp_vector = comp_vector % rdi->ibdev.num_comp_vectors;
+
/* Allocate the completion queue structure. */
cq = kzalloc_node(sizeof(*cq), GFP_KERNEL, rdi->dparms.node);
if (!cq)
@@ -267,14 +268,22 @@ struct ib_cq *rvt_create_cq(struct ib_device *ibdev,
* an error.
*/
cq->rdi = rdi;
+ if (rdi->driver_f.comp_vect_cpu_lookup)
+ cq->comp_vector_cpu =
+ rdi->driver_f.comp_vect_cpu_lookup(rdi, comp_vector);
+ else
+ cq->comp_vector_cpu =
+ cpumask_first(cpumask_of_node(rdi->dparms.node));
+
cq->ibcq.cqe = entries;
cq->notify = RVT_CQ_NONE;
spin_lock_init(&cq->lock);
- kthread_init_work(&cq->comptask, send_complete);
+ INIT_WORK(&cq->comptask, send_complete);
cq->queue = wc;
ret = &cq->ibcq;
+ trace_rvt_create_cq(cq, attr);
goto done;
bail_ip:
@@ -300,7 +309,7 @@ int rvt_destroy_cq(struct ib_cq *ibcq)
struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
struct rvt_dev_info *rdi = cq->rdi;
- kthread_flush_work(&cq->comptask);
+ flush_work(&cq->comptask);
spin_lock_irq(&rdi->n_cqs_lock);
rdi->n_cqs_allocated--;
spin_unlock_irq(&rdi->n_cqs_lock);
@@ -510,24 +519,13 @@ int rvt_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
*
* Return: 0 on success
*/
-int rvt_driver_cq_init(struct rvt_dev_info *rdi)
+int rvt_driver_cq_init(void)
{
- int cpu;
- struct kthread_worker *worker;
-
- if (rcu_access_pointer(rdi->worker))
- return 0;
-
- spin_lock_init(&rdi->n_cqs_lock);
-
- cpu = cpumask_first(cpumask_of_node(rdi->dparms.node));
- worker = kthread_create_worker_on_cpu(cpu, 0,
- "%s", rdi->dparms.cq_name);
- if (IS_ERR(worker))
- return PTR_ERR(worker);
+ comp_vector_wq = alloc_workqueue("%s", WQ_HIGHPRI | WQ_CPU_INTENSIVE,
+ 0, "rdmavt_cq");
+ if (!comp_vector_wq)
+ return -ENOMEM;
- set_user_nice(worker->task, MIN_NICE);
- RCU_INIT_POINTER(rdi->worker, worker);
return 0;
}
@@ -535,23 +533,8 @@ int rvt_driver_cq_init(struct rvt_dev_info *rdi)
* rvt_cq_exit - tear down cq reources
* @rdi: rvt dev structure
*/
-void rvt_cq_exit(struct rvt_dev_info *rdi)
+void rvt_cq_exit(void)
{
- struct kthread_worker *worker;
-
- if (!rcu_access_pointer(rdi->worker))
- return;
-
- spin_lock(&rdi->n_cqs_lock);
- worker = rcu_dereference_protected(rdi->worker,
- lockdep_is_held(&rdi->n_cqs_lock));
- if (!worker) {
- spin_unlock(&rdi->n_cqs_lock);
- return;
- }
- RCU_INIT_POINTER(rdi->worker, NULL);
- spin_unlock(&rdi->n_cqs_lock);
- synchronize_rcu();
-
- kthread_destroy_worker(worker);
+ destroy_workqueue(comp_vector_wq);
+ comp_vector_wq = NULL;
}