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author | Sebastian Sanchez <sebastian.sanchez@intel.com> | 2018-05-02 16:43:55 +0300 |
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committer | Doug Ledford <dledford@redhat.com> | 2018-05-09 22:53:30 +0300 |
commit | 5d18ee67d4c1735f5c1f757e89228ec68e4f4ef3 (patch) | |
tree | bee1ad21ecea953b9048b94fd05b2c86a4128c27 /include/rdma/rdma_vt.h | |
parent | cf38ea100edfcc0ec0a5797966d69ec4e10fe4f1 (diff) | |
download | linux-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 'include/rdma/rdma_vt.h')
-rw-r--r-- | include/rdma/rdma_vt.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/rdma/rdma_vt.h b/include/rdma/rdma_vt.h index eec495e68823..e79229a0cf01 100644 --- a/include/rdma/rdma_vt.h +++ b/include/rdma/rdma_vt.h @@ -2,7 +2,7 @@ #define DEF_RDMA_VT_H /* - * 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. @@ -167,7 +167,6 @@ struct rvt_driver_params { int qpn_res_end; int nports; int npkeys; - char cq_name[RVT_CQN_MAX]; int node; int psn_mask; int psn_shift; @@ -347,6 +346,9 @@ struct rvt_driver_provided { /* Notify driver to restart rc */ void (*notify_restart_rc)(struct rvt_qp *qp, u32 psn, int wait); + + /* Get and return CPU to pin CQ processing thread */ + int (*comp_vect_cpu_lookup)(struct rvt_dev_info *rdi, int comp_vect); }; struct rvt_dev_info { @@ -402,7 +404,6 @@ struct rvt_dev_info { spinlock_t pending_lock; /* protect pending mmap list */ /* CQ */ - struct kthread_worker __rcu *worker; /* per device cq worker */ u32 n_cqs_allocated; /* number of CQs allocated for device */ spinlock_t n_cqs_lock; /* protect count of in use cqs */ |