From 6f3ca6f4f5e05b52bf6851ada21026faa106de76 Mon Sep 17 00:00:00 2001 From: Maor Gottlieb Date: Mon, 6 Jul 2020 15:27:16 +0300 Subject: [PATCH] RDMA/core: Optimize XRC target lookup Replace the mutex with read write semaphore and use xarray instead of linked list for XRC target QPs. This will give faster XRC target lookup. In addition, when QP is closed, don't insert it back to the xarray if the destroy command failed. Link: https://lore.kernel.org/r/20200706122716.647338-4-leon@kernel.org Signed-off-by: Maor Gottlieb Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/verbs.c | 57 ++++++++++++--------------------- include/rdma/ib_verbs.h | 5 ++- 2 files changed, 23 insertions(+), 39 deletions(-) diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c index a9b99c3ff25c..b1b6cc21ca96 100644 --- a/drivers/infiniband/core/verbs.c +++ b/drivers/infiniband/core/verbs.c @@ -1090,13 +1090,6 @@ static void __ib_shared_qp_event_handler(struct ib_event *event, void *context) spin_unlock_irqrestore(&qp->device->qp_open_list_lock, flags); } -static void __ib_insert_xrcd_qp(struct ib_xrcd *xrcd, struct ib_qp *qp) -{ - mutex_lock(&xrcd->tgt_qp_mutex); - list_add(&qp->xrcd_list, &xrcd->tgt_qp_list); - mutex_unlock(&xrcd->tgt_qp_mutex); -} - static struct ib_qp *__ib_open_qp(struct ib_qp *real_qp, void (*event_handler)(struct ib_event *, void *), void *qp_context) @@ -1139,16 +1132,15 @@ struct ib_qp *ib_open_qp(struct ib_xrcd *xrcd, if (qp_open_attr->qp_type != IB_QPT_XRC_TGT) return ERR_PTR(-EINVAL); - qp = ERR_PTR(-EINVAL); - mutex_lock(&xrcd->tgt_qp_mutex); - list_for_each_entry(real_qp, &xrcd->tgt_qp_list, xrcd_list) { - if (real_qp->qp_num == qp_open_attr->qp_num) { - qp = __ib_open_qp(real_qp, qp_open_attr->event_handler, - qp_open_attr->qp_context); - break; - } + down_read(&xrcd->tgt_qps_rwsem); + real_qp = xa_load(&xrcd->tgt_qps, qp_open_attr->qp_num); + if (!real_qp) { + up_read(&xrcd->tgt_qps_rwsem); + return ERR_PTR(-EINVAL); } - mutex_unlock(&xrcd->tgt_qp_mutex); + qp = __ib_open_qp(real_qp, qp_open_attr->event_handler, + qp_open_attr->qp_context); + up_read(&xrcd->tgt_qps_rwsem); return qp; } EXPORT_SYMBOL(ib_open_qp); @@ -1157,6 +1149,7 @@ static struct ib_qp *create_xrc_qp_user(struct ib_qp *qp, struct ib_qp_init_attr *qp_init_attr) { struct ib_qp *real_qp = qp; + int err; qp->event_handler = __ib_shared_qp_event_handler; qp->qp_context = qp; @@ -1172,7 +1165,12 @@ static struct ib_qp *create_xrc_qp_user(struct ib_qp *qp, if (IS_ERR(qp)) return qp; - __ib_insert_xrcd_qp(qp_init_attr->xrcd, real_qp); + err = xa_err(xa_store(&qp_init_attr->xrcd->tgt_qps, real_qp->qp_num, + real_qp, GFP_KERNEL)); + if (err) { + ib_close_qp(qp); + return ERR_PTR(err); + } return qp; } @@ -1887,21 +1885,18 @@ static int __ib_destroy_shared_qp(struct ib_qp *qp) real_qp = qp->real_qp; xrcd = real_qp->xrcd; - - mutex_lock(&xrcd->tgt_qp_mutex); + down_write(&xrcd->tgt_qps_rwsem); ib_close_qp(qp); if (atomic_read(&real_qp->usecnt) == 0) - list_del(&real_qp->xrcd_list); + xa_erase(&xrcd->tgt_qps, real_qp->qp_num); else real_qp = NULL; - mutex_unlock(&xrcd->tgt_qp_mutex); + up_write(&xrcd->tgt_qps_rwsem); if (real_qp) { ret = ib_destroy_qp(real_qp); if (!ret) atomic_dec(&xrcd->usecnt); - else - __ib_insert_xrcd_qp(xrcd, real_qp); } return 0; @@ -2307,8 +2302,8 @@ struct ib_xrcd *ib_alloc_xrcd_user(struct ib_device *device, xrcd->device = device; xrcd->inode = inode; atomic_set(&xrcd->usecnt, 0); - mutex_init(&xrcd->tgt_qp_mutex); - INIT_LIST_HEAD(&xrcd->tgt_qp_list); + init_rwsem(&xrcd->tgt_qps_rwsem); + xa_init(&xrcd->tgt_qps); } return xrcd; @@ -2322,20 +2317,10 @@ EXPORT_SYMBOL(ib_alloc_xrcd_user); */ int ib_dealloc_xrcd_user(struct ib_xrcd *xrcd, struct ib_udata *udata) { - struct ib_qp *qp; - int ret; - if (atomic_read(&xrcd->usecnt)) return -EBUSY; - while (!list_empty(&xrcd->tgt_qp_list)) { - qp = list_entry(xrcd->tgt_qp_list.next, struct ib_qp, xrcd_list); - ret = ib_destroy_qp(qp); - if (ret) - return ret; - } - mutex_destroy(&xrcd->tgt_qp_mutex); - + WARN_ON(!xa_empty(&xrcd->tgt_qps)); return xrcd->device->ops.dealloc_xrcd(xrcd, udata); } EXPORT_SYMBOL(ib_dealloc_xrcd_user); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index db6f78c5394f..20c801730fed 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -1567,9 +1567,8 @@ struct ib_xrcd { struct ib_device *device; atomic_t usecnt; /* count all exposed resources */ struct inode *inode; - - struct mutex tgt_qp_mutex; - struct list_head tgt_qp_list; + struct rw_semaphore tgt_qps_rwsem; + struct xarray tgt_qps; }; struct ib_ah {