diff options
Diffstat (limited to 'net/rds/ib_rdma.c')
| -rw-r--r-- | net/rds/ib_rdma.c | 291 |
1 files changed, 219 insertions, 72 deletions
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c index 4b0da865a72..e8fdb172adb 100644 --- a/net/rds/ib_rdma.c +++ b/net/rds/ib_rdma.c @@ -31,11 +31,15 @@ * */ #include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/rculist.h> +#include <linux/llist.h> #include "rds.h" -#include "rdma.h" #include "ib.h" +static DEFINE_PER_CPU(unsigned long, clean_list_grace); +#define CLEAN_LIST_BUSY_BIT 0 /* * This is stored as mr->r_trans_private. @@ -44,7 +48,11 @@ struct rds_ib_mr { struct rds_ib_device *device; struct rds_ib_mr_pool *pool; struct ib_fmr *fmr; - struct list_head list; + + struct llist_node llnode; + + /* unmap_list is for freeing */ + struct list_head unmap_list; unsigned int remap_count; struct scatterlist *sg; @@ -58,14 +66,16 @@ struct rds_ib_mr { */ struct rds_ib_mr_pool { struct mutex flush_lock; /* serialize fmr invalidate */ - struct work_struct flush_worker; /* flush worker */ + struct delayed_work flush_worker; /* flush worker */ - spinlock_t list_lock; /* protect variables below */ atomic_t item_count; /* total # of MRs */ atomic_t dirty_count; /* # dirty of MRs */ - struct list_head drop_list; /* MRs that have reached their max_maps limit */ - struct list_head free_list; /* unused MRs */ - struct list_head clean_list; /* unused & unamapped MRs */ + + struct llist_head drop_list; /* MRs that have reached their max_maps limit */ + struct llist_head free_list; /* unused MRs */ + struct llist_head clean_list; /* global unused & unamapped MRs */ + wait_queue_head_t flush_wait; + atomic_t free_pinned; /* memory pinned by free MRs */ unsigned long max_items; unsigned long max_items_soft; @@ -73,7 +83,7 @@ struct rds_ib_mr_pool { struct ib_fmr_attr fmr_attr; }; -static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all); +static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all, struct rds_ib_mr **); static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr); static void rds_ib_mr_pool_flush_worker(struct work_struct *work); @@ -82,16 +92,17 @@ static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr) struct rds_ib_device *rds_ibdev; struct rds_ib_ipaddr *i_ipaddr; - list_for_each_entry(rds_ibdev, &rds_ib_devices, list) { - spin_lock_irq(&rds_ibdev->spinlock); - list_for_each_entry(i_ipaddr, &rds_ibdev->ipaddr_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) { + list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) { if (i_ipaddr->ipaddr == ipaddr) { - spin_unlock_irq(&rds_ibdev->spinlock); + atomic_inc(&rds_ibdev->refcount); + rcu_read_unlock(); return rds_ibdev; } } - spin_unlock_irq(&rds_ibdev->spinlock); } + rcu_read_unlock(); return NULL; } @@ -107,7 +118,7 @@ static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) i_ipaddr->ipaddr = ipaddr; spin_lock_irq(&rds_ibdev->spinlock); - list_add_tail(&i_ipaddr->list, &rds_ibdev->ipaddr_list); + list_add_tail_rcu(&i_ipaddr->list, &rds_ibdev->ipaddr_list); spin_unlock_irq(&rds_ibdev->spinlock); return 0; @@ -115,17 +126,24 @@ static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) { - struct rds_ib_ipaddr *i_ipaddr, *next; + struct rds_ib_ipaddr *i_ipaddr; + struct rds_ib_ipaddr *to_free = NULL; + spin_lock_irq(&rds_ibdev->spinlock); - list_for_each_entry_safe(i_ipaddr, next, &rds_ibdev->ipaddr_list, list) { + list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) { if (i_ipaddr->ipaddr == ipaddr) { - list_del(&i_ipaddr->list); - kfree(i_ipaddr); + list_del_rcu(&i_ipaddr->list); + to_free = i_ipaddr; break; } } spin_unlock_irq(&rds_ibdev->spinlock); + + if (to_free) { + synchronize_rcu(); + kfree(to_free); + } } int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) @@ -133,8 +151,10 @@ int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) struct rds_ib_device *rds_ibdev_old; rds_ibdev_old = rds_ib_get_device(ipaddr); - if (rds_ibdev_old) + if (rds_ibdev_old) { rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr); + rds_ib_dev_put(rds_ibdev_old); + } return rds_ib_add_ipaddr(rds_ibdev, ipaddr); } @@ -149,12 +169,13 @@ void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *con BUG_ON(list_empty(&ic->ib_node)); list_del(&ic->ib_node); - spin_lock_irq(&rds_ibdev->spinlock); + spin_lock(&rds_ibdev->spinlock); list_add_tail(&ic->ib_node, &rds_ibdev->conn_list); - spin_unlock_irq(&rds_ibdev->spinlock); + spin_unlock(&rds_ibdev->spinlock); spin_unlock_irq(&ib_nodev_conns_lock); ic->rds_ibdev = rds_ibdev; + atomic_inc(&rds_ibdev->refcount); } void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn) @@ -174,18 +195,18 @@ void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection * spin_unlock(&ib_nodev_conns_lock); ic->rds_ibdev = NULL; + rds_ib_dev_put(rds_ibdev); } -void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock) +void rds_ib_destroy_nodev_conns(void) { struct rds_ib_connection *ic, *_ic; LIST_HEAD(tmp_list); /* avoid calling conn_destroy with irqs off */ - spin_lock_irq(list_lock); - list_splice(list, &tmp_list); - INIT_LIST_HEAD(list); - spin_unlock_irq(list_lock); + spin_lock_irq(&ib_nodev_conns_lock); + list_splice(&ib_nodev_conns, &tmp_list); + spin_unlock_irq(&ib_nodev_conns_lock); list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) rds_conn_destroy(ic->conn); @@ -199,12 +220,12 @@ struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev) if (!pool) return ERR_PTR(-ENOMEM); - INIT_LIST_HEAD(&pool->free_list); - INIT_LIST_HEAD(&pool->drop_list); - INIT_LIST_HEAD(&pool->clean_list); + init_llist_head(&pool->free_list); + init_llist_head(&pool->drop_list); + init_llist_head(&pool->clean_list); mutex_init(&pool->flush_lock); - spin_lock_init(&pool->list_lock); - INIT_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker); + init_waitqueue_head(&pool->flush_wait); + INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker); pool->fmr_attr.max_pages = fmr_message_size; pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps; @@ -232,34 +253,52 @@ void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_co void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool) { - flush_workqueue(rds_wq); - rds_ib_flush_mr_pool(pool, 1); - BUG_ON(atomic_read(&pool->item_count)); - BUG_ON(atomic_read(&pool->free_pinned)); + cancel_delayed_work_sync(&pool->flush_worker); + rds_ib_flush_mr_pool(pool, 1, NULL); + WARN_ON(atomic_read(&pool->item_count)); + WARN_ON(atomic_read(&pool->free_pinned)); kfree(pool); } static inline struct rds_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool) { struct rds_ib_mr *ibmr = NULL; - unsigned long flags; + struct llist_node *ret; + unsigned long *flag; - spin_lock_irqsave(&pool->list_lock, flags); - if (!list_empty(&pool->clean_list)) { - ibmr = list_entry(pool->clean_list.next, struct rds_ib_mr, list); - list_del_init(&ibmr->list); - } - spin_unlock_irqrestore(&pool->list_lock, flags); + preempt_disable(); + flag = &__get_cpu_var(clean_list_grace); + set_bit(CLEAN_LIST_BUSY_BIT, flag); + ret = llist_del_first(&pool->clean_list); + if (ret) + ibmr = llist_entry(ret, struct rds_ib_mr, llnode); + clear_bit(CLEAN_LIST_BUSY_BIT, flag); + preempt_enable(); return ibmr; } +static inline void wait_clean_list_grace(void) +{ + int cpu; + unsigned long *flag; + + for_each_online_cpu(cpu) { + flag = &per_cpu(clean_list_grace, cpu); + while (test_bit(CLEAN_LIST_BUSY_BIT, flag)) + cpu_relax(); + } +} + static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev) { struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; struct rds_ib_mr *ibmr = NULL; int err = 0, iter = 0; + if (atomic_read(&pool->dirty_count) >= pool->max_items / 10) + schedule_delayed_work(&pool->flush_worker, 10); + while (1) { ibmr = rds_ib_reuse_fmr(pool); if (ibmr) @@ -286,19 +325,24 @@ static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev) /* We do have some empty MRs. Flush them out. */ rds_ib_stats_inc(s_ib_rdma_mr_pool_wait); - rds_ib_flush_mr_pool(pool, 0); + rds_ib_flush_mr_pool(pool, 0, &ibmr); + if (ibmr) + return ibmr; } - ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL); + ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL, rdsibdev_to_node(rds_ibdev)); if (!ibmr) { err = -ENOMEM; goto out_no_cigar; } + memset(ibmr, 0, sizeof(*ibmr)); + ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd, (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ | - IB_ACCESS_REMOTE_WRITE), + IB_ACCESS_REMOTE_WRITE| + IB_ACCESS_REMOTE_ATOMIC), &pool->fmr_attr); if (IS_ERR(ibmr->fmr)) { err = PTR_ERR(ibmr->fmr); @@ -366,7 +410,8 @@ static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibm if (page_cnt > fmr_message_size) return -EINVAL; - dma_pages = kmalloc(sizeof(u64) * page_cnt, GFP_ATOMIC); + dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC, + rdsibdev_to_node(rds_ibdev)); if (!dma_pages) return -ENOMEM; @@ -440,6 +485,7 @@ static void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr) /* FIXME we need a way to tell a r/w MR * from a r/o MR */ + BUG_ON(irqs_disabled()); set_page_dirty(page); put_page(page); } @@ -475,33 +521,107 @@ static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int fr } /* + * given an llist of mrs, put them all into the list_head for more processing + */ +static void llist_append_to_list(struct llist_head *llist, struct list_head *list) +{ + struct rds_ib_mr *ibmr; + struct llist_node *node; + struct llist_node *next; + + node = llist_del_all(llist); + while (node) { + next = node->next; + ibmr = llist_entry(node, struct rds_ib_mr, llnode); + list_add_tail(&ibmr->unmap_list, list); + node = next; + } +} + +/* + * this takes a list head of mrs and turns it into linked llist nodes + * of clusters. Each cluster has linked llist nodes of + * MR_CLUSTER_SIZE mrs that are ready for reuse. + */ +static void list_to_llist_nodes(struct rds_ib_mr_pool *pool, + struct list_head *list, + struct llist_node **nodes_head, + struct llist_node **nodes_tail) +{ + struct rds_ib_mr *ibmr; + struct llist_node *cur = NULL; + struct llist_node **next = nodes_head; + + list_for_each_entry(ibmr, list, unmap_list) { + cur = &ibmr->llnode; + *next = cur; + next = &cur->next; + } + *next = NULL; + *nodes_tail = cur; +} + +/* * Flush our pool of MRs. * At a minimum, all currently unused MRs are unmapped. * If the number of MRs allocated exceeds the limit, we also try * to free as many MRs as needed to get back to this limit. */ -static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all) +static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, + int free_all, struct rds_ib_mr **ibmr_ret) { struct rds_ib_mr *ibmr, *next; + struct llist_node *clean_nodes; + struct llist_node *clean_tail; LIST_HEAD(unmap_list); LIST_HEAD(fmr_list); unsigned long unpinned = 0; - unsigned long flags; unsigned int nfreed = 0, ncleaned = 0, free_goal; int ret = 0; rds_ib_stats_inc(s_ib_rdma_mr_pool_flush); - mutex_lock(&pool->flush_lock); + if (ibmr_ret) { + DEFINE_WAIT(wait); + while(!mutex_trylock(&pool->flush_lock)) { + ibmr = rds_ib_reuse_fmr(pool); + if (ibmr) { + *ibmr_ret = ibmr; + finish_wait(&pool->flush_wait, &wait); + goto out_nolock; + } + + prepare_to_wait(&pool->flush_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (llist_empty(&pool->clean_list)) + schedule(); + + ibmr = rds_ib_reuse_fmr(pool); + if (ibmr) { + *ibmr_ret = ibmr; + finish_wait(&pool->flush_wait, &wait); + goto out_nolock; + } + } + finish_wait(&pool->flush_wait, &wait); + } else + mutex_lock(&pool->flush_lock); + + if (ibmr_ret) { + ibmr = rds_ib_reuse_fmr(pool); + if (ibmr) { + *ibmr_ret = ibmr; + goto out; + } + } - spin_lock_irqsave(&pool->list_lock, flags); /* Get the list of all MRs to be dropped. Ordering matters - - * we want to put drop_list ahead of free_list. */ - list_splice_init(&pool->free_list, &unmap_list); - list_splice_init(&pool->drop_list, &unmap_list); + * we want to put drop_list ahead of free_list. + */ + llist_append_to_list(&pool->drop_list, &unmap_list); + llist_append_to_list(&pool->free_list, &unmap_list); if (free_all) - list_splice_init(&pool->clean_list, &unmap_list); - spin_unlock_irqrestore(&pool->list_lock, flags); + llist_append_to_list(&pool->clean_list, &unmap_list); free_goal = rds_ib_flush_goal(pool, free_all); @@ -509,19 +629,20 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all) goto out; /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */ - list_for_each_entry(ibmr, &unmap_list, list) + list_for_each_entry(ibmr, &unmap_list, unmap_list) list_add(&ibmr->fmr->list, &fmr_list); + ret = ib_unmap_fmr(&fmr_list); if (ret) printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret); /* Now we can destroy the DMA mapping and unpin any pages */ - list_for_each_entry_safe(ibmr, next, &unmap_list, list) { + list_for_each_entry_safe(ibmr, next, &unmap_list, unmap_list) { unpinned += ibmr->sg_len; __rds_ib_teardown_mr(ibmr); if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) { rds_ib_stats_inc(s_ib_rdma_mr_free); - list_del(&ibmr->list); + list_del(&ibmr->unmap_list); ib_dealloc_fmr(ibmr->fmr); kfree(ibmr); nfreed++; @@ -529,9 +650,27 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all) ncleaned++; } - spin_lock_irqsave(&pool->list_lock, flags); - list_splice(&unmap_list, &pool->clean_list); - spin_unlock_irqrestore(&pool->list_lock, flags); + if (!list_empty(&unmap_list)) { + /* we have to make sure that none of the things we're about + * to put on the clean list would race with other cpus trying + * to pull items off. The llist would explode if we managed to + * remove something from the clean list and then add it back again + * while another CPU was spinning on that same item in llist_del_first. + * + * This is pretty unlikely, but just in case wait for an llist grace period + * here before adding anything back into the clean list. + */ + wait_clean_list_grace(); + + list_to_llist_nodes(pool, &unmap_list, &clean_nodes, &clean_tail); + if (ibmr_ret) + *ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode); + + /* more than one entry in llist nodes */ + if (clean_nodes->next) + llist_add_batch(clean_nodes->next, clean_tail, &pool->clean_list); + + } atomic_sub(unpinned, &pool->free_pinned); atomic_sub(ncleaned, &pool->dirty_count); @@ -539,14 +678,17 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all) out: mutex_unlock(&pool->flush_lock); + if (waitqueue_active(&pool->flush_wait)) + wake_up(&pool->flush_wait); +out_nolock: return ret; } static void rds_ib_mr_pool_flush_worker(struct work_struct *work) { - struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker); + struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work); - rds_ib_flush_mr_pool(pool, 0); + rds_ib_flush_mr_pool(pool, 0, NULL); } void rds_ib_free_mr(void *trans_private, int invalidate) @@ -554,47 +696,48 @@ void rds_ib_free_mr(void *trans_private, int invalidate) struct rds_ib_mr *ibmr = trans_private; struct rds_ib_device *rds_ibdev = ibmr->device; struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; - unsigned long flags; rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len); /* Return it to the pool's free list */ - spin_lock_irqsave(&pool->list_lock, flags); if (ibmr->remap_count >= pool->fmr_attr.max_maps) - list_add(&ibmr->list, &pool->drop_list); + llist_add(&ibmr->llnode, &pool->drop_list); else - list_add(&ibmr->list, &pool->free_list); + llist_add(&ibmr->llnode, &pool->free_list); atomic_add(ibmr->sg_len, &pool->free_pinned); atomic_inc(&pool->dirty_count); - spin_unlock_irqrestore(&pool->list_lock, flags); /* If we've pinned too many pages, request a flush */ if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned || atomic_read(&pool->dirty_count) >= pool->max_items / 10) - queue_work(rds_wq, &pool->flush_worker); + schedule_delayed_work(&pool->flush_worker, 10); if (invalidate) { if (likely(!in_interrupt())) { - rds_ib_flush_mr_pool(pool, 0); + rds_ib_flush_mr_pool(pool, 0, NULL); } else { /* We get here if the user created a MR marked * as use_once and invalidate at the same time. */ - queue_work(rds_wq, &pool->flush_worker); + schedule_delayed_work(&pool->flush_worker, 10); } } + + rds_ib_dev_put(rds_ibdev); } void rds_ib_flush_mrs(void) { struct rds_ib_device *rds_ibdev; + down_read(&rds_ib_devices_lock); list_for_each_entry(rds_ibdev, &rds_ib_devices, list) { struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; if (pool) - rds_ib_flush_mr_pool(pool, 0); + rds_ib_flush_mr_pool(pool, 0, NULL); } + up_read(&rds_ib_devices_lock); } void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, @@ -626,6 +769,7 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret); ibmr->device = rds_ibdev; + rds_ibdev = NULL; out: if (ret) { @@ -633,5 +777,8 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, rds_ib_free_mr(ibmr, 0); ibmr = ERR_PTR(ret); } + if (rds_ibdev) + rds_ib_dev_put(rds_ibdev); return ibmr; } + |