linux/drivers/infiniband/hw/hfi1/affinity.h
Sebastian Sanchez 5d18ee67d4 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>
2018-05-09 15:53:30 -04:00

129 lines
4.1 KiB
C

/*
* Copyright(c) 2015 - 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.
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* GPL LICENSE SUMMARY
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#ifndef _HFI1_AFFINITY_H
#define _HFI1_AFFINITY_H
#include "hfi.h"
enum irq_type {
IRQ_SDMA,
IRQ_RCVCTXT,
IRQ_GENERAL,
IRQ_OTHER
};
/* Can be used for both memory and cpu */
enum affinity_flags {
AFF_AUTO,
AFF_NUMA_LOCAL,
AFF_DEV_LOCAL,
AFF_IRQ_LOCAL
};
struct cpu_mask_set {
struct cpumask mask;
struct cpumask used;
uint gen;
};
struct hfi1_msix_entry;
/* Initialize non-HT cpu cores mask */
void init_real_cpu_mask(void);
/* Initialize driver affinity data */
int hfi1_dev_affinity_init(struct hfi1_devdata *dd);
/*
* Set IRQ affinity to a CPU. The function will determine the
* CPU and set the affinity to it.
*/
int hfi1_get_irq_affinity(struct hfi1_devdata *dd,
struct hfi1_msix_entry *msix);
/*
* Remove the IRQ's CPU affinity. This function also updates
* any internal CPU tracking data
*/
void hfi1_put_irq_affinity(struct hfi1_devdata *dd,
struct hfi1_msix_entry *msix);
/*
* Determine a CPU affinity for a user process, if the process does not
* have an affinity set yet.
*/
int hfi1_get_proc_affinity(int node);
/* Release a CPU used by a user process. */
void hfi1_put_proc_affinity(int cpu);
struct hfi1_affinity_node {
int node;
u16 __percpu *comp_vect_affinity;
struct cpu_mask_set def_intr;
struct cpu_mask_set rcv_intr;
struct cpumask general_intr_mask;
struct cpumask comp_vect_mask;
struct list_head list;
};
struct hfi1_affinity_node_list {
struct list_head list;
struct cpumask real_cpu_mask;
struct cpu_mask_set proc;
int num_core_siblings;
int num_possible_nodes;
int num_online_nodes;
int num_online_cpus;
struct mutex lock; /* protects affinity nodes */
};
int node_affinity_init(void);
void node_affinity_destroy_all(void);
extern struct hfi1_affinity_node_list node_affinity;
void hfi1_dev_affinity_clean_up(struct hfi1_devdata *dd);
int hfi1_comp_vect_mappings_lookup(struct rvt_dev_info *rdi, int comp_vect);
int hfi1_comp_vectors_set_up(struct hfi1_devdata *dd);
void hfi1_comp_vectors_clean_up(struct hfi1_devdata *dd);
#endif /* _HFI1_AFFINITY_H */