diff options
| -rw-r--r-- | net/rds/ib.h | 19 | ||||
| -rw-r--r-- | net/rds/ib_cm.c | 9 | ||||
| -rw-r--r-- | net/rds/ib_recv.c | 321 |
3 files changed, 297 insertions, 52 deletions
diff --git a/net/rds/ib.h b/net/rds/ib.h index 9bb7a74..2efd9d1 100644 --- a/net/rds/ib.h +++ b/net/rds/ib.h @@ -21,6 +21,8 @@ #define RDS_IB_SUPPORTED_PROTOCOLS 0x00000003 /* minor versions supported */ +#define RDS_IB_RECYCLE_BATCH_COUNT 32 + extern struct list_head rds_ib_devices; /* @@ -30,14 +32,27 @@ extern struct list_head rds_ib_devices; */ struct rds_page_frag { struct list_head f_item; + struct list_head f_cache_entry; struct scatterlist f_sg; }; struct rds_ib_incoming { struct list_head ii_frags; + struct list_head ii_cache_entry; struct rds_incoming ii_inc; }; +struct rds_ib_cache_head { + struct list_head *first; + unsigned long count; +}; + +struct rds_ib_refill_cache { + struct rds_ib_cache_head *percpu; + struct list_head *xfer; + struct list_head *ready; +}; + struct rds_ib_connect_private { /* Add new fields at the end, and don't permute existing fields. */ __be32 dp_saddr; @@ -104,6 +119,8 @@ struct rds_ib_connection { u64 i_recv_hdrs_dma; struct rds_ib_recv_work *i_recvs; u64 i_ack_recv; /* last ACK received */ + struct rds_ib_refill_cache i_cache_incs; + struct rds_ib_refill_cache i_cache_frags; /* sending acks */ unsigned long i_ack_flags; @@ -304,6 +321,8 @@ void rds_ib_flush_mrs(void); int __init rds_ib_recv_init(void); void rds_ib_recv_exit(void); int rds_ib_recv(struct rds_connection *conn); +int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic); +void rds_ib_recv_free_caches(struct rds_ib_connection *ic); int rds_ib_recv_refill(struct rds_connection *conn, int prefill); void rds_ib_inc_free(struct rds_incoming *inc); int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov, diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c index a9fb917..10f6a88 100644 --- a/net/rds/ib_cm.c +++ b/net/rds/ib_cm.c @@ -709,12 +709,19 @@ int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp) { struct rds_ib_connection *ic; unsigned long flags; + int ret; /* XXX too lazy? */ ic = kzalloc(sizeof(struct rds_ib_connection), GFP_KERNEL); if (!ic) return -ENOMEM; + ret = rds_ib_recv_alloc_caches(ic); + if (ret) { + kfree(ic); + return ret; + } + INIT_LIST_HEAD(&ic->ib_node); tasklet_init(&ic->i_recv_tasklet, rds_ib_recv_tasklet_fn, (unsigned long) ic); @@ -763,6 +770,8 @@ void rds_ib_conn_free(void *arg) list_del(&ic->ib_node); spin_unlock_irq(lock_ptr); + rds_ib_recv_free_caches(ic); + kfree(ic); } diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c index 48add10..5b429b7 100644 --- a/net/rds/ib_recv.c +++ b/net/rds/ib_recv.c @@ -43,14 +43,6 @@ static struct kmem_cache *rds_ib_incoming_slab; static struct kmem_cache *rds_ib_frag_slab; static atomic_t rds_ib_allocation = ATOMIC_INIT(0); -/* Free frag and attached recv buffer f_sg */ -static void rds_ib_frag_free(struct rds_page_frag *frag) -{ - rdsdebug("frag %p page %p\n", frag, sg_page(&frag->f_sg)); - __free_page(sg_page(&frag->f_sg)); - kmem_cache_free(rds_ib_frag_slab, frag); -} - void rds_ib_recv_init_ring(struct rds_ib_connection *ic) { struct rds_ib_recv_work *recv; @@ -79,6 +71,151 @@ void rds_ib_recv_init_ring(struct rds_ib_connection *ic) } } +/* + * The entire 'from' list, including the from element itself, is put on + * to the tail of the 'to' list. + */ +static void list_splice_entire_tail(struct list_head *from, + struct list_head *to) +{ + struct list_head *from_last = from->prev; + + list_splice_tail(from_last, to); + list_add_tail(from_last, to); +} + +static void rds_ib_cache_xfer_to_ready(struct rds_ib_refill_cache *cache) +{ + struct list_head *tmp; + + tmp = xchg(&cache->xfer, NULL); + if (tmp) { + if (cache->ready) + list_splice_entire_tail(tmp, cache->ready); + else + cache->ready = tmp; + } +} + +static int rds_ib_recv_alloc_cache(struct rds_ib_refill_cache *cache) +{ + struct rds_ib_cache_head *head; + int cpu; + + cache->percpu = alloc_percpu(struct rds_ib_cache_head); + if (!cache->percpu) + return -ENOMEM; + + for_each_possible_cpu(cpu) { + head = per_cpu_ptr(cache->percpu, cpu); + head->first = NULL; + head->count = 0; + } + cache->xfer = NULL; + cache->ready = NULL; + + return 0; +} + +int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic) +{ + int ret; + + ret = rds_ib_recv_alloc_cache(&ic->i_cache_incs); + if (!ret) { + ret = rds_ib_recv_alloc_cache(&ic->i_cache_frags); + if (ret) + free_percpu(ic->i_cache_incs.percpu); + } + + return ret; +} + +static void rds_ib_cache_splice_all_lists(struct rds_ib_refill_cache *cache, + struct list_head *caller_list) +{ + struct rds_ib_cache_head *head; + int cpu; + + for_each_possible_cpu(cpu) { + head = per_cpu_ptr(cache->percpu, cpu); + if (head->first) { + list_splice_entire_tail(head->first, caller_list); + head->first = NULL; + } + } + + if (cache->ready) { + list_splice_entire_tail(cache->ready, caller_list); + cache->ready = NULL; + } +} + +void rds_ib_recv_free_caches(struct rds_ib_connection *ic) +{ + struct rds_ib_incoming *inc; + struct rds_ib_incoming *inc_tmp; + struct rds_page_frag *frag; + struct rds_page_frag *frag_tmp; + LIST_HEAD(list); + + rds_ib_cache_xfer_to_ready(&ic->i_cache_incs); + rds_ib_cache_splice_all_lists(&ic->i_cache_incs, &list); + free_percpu(ic->i_cache_incs.percpu); + + list_for_each_entry_safe(inc, inc_tmp, &list, ii_cache_entry) { + list_del(&inc->ii_cache_entry); + WARN_ON(!list_empty(&inc->ii_frags)); + kmem_cache_free(rds_ib_incoming_slab, inc); + } + + rds_ib_cache_xfer_to_ready(&ic->i_cache_frags); + rds_ib_cache_splice_all_lists(&ic->i_cache_frags, &list); + free_percpu(ic->i_cache_frags.percpu); + + list_for_each_entry_safe(frag, frag_tmp, &list, f_cache_entry) { + list_del(&frag->f_cache_entry); + WARN_ON(!list_empty(&frag->f_item)); + kmem_cache_free(rds_ib_frag_slab, frag); + } +} + +/* fwd decl */ +static void rds_ib_recv_cache_put(struct list_head *new_item, + struct rds_ib_refill_cache *cache); +static struct list_head *rds_ib_recv_cache_get(struct rds_ib_refill_cache *cache); + + +/* Recycle frag and attached recv buffer f_sg */ +static void rds_ib_frag_free(struct rds_ib_connection *ic, + struct rds_page_frag *frag) +{ + rdsdebug("frag %p page %p\n", frag, sg_page(&frag->f_sg)); + + rds_ib_recv_cache_put(&frag->f_cache_entry, &ic->i_cache_frags); +} + +/* Recycle inc after freeing attached frags */ +void rds_ib_inc_free(struct rds_incoming *inc) +{ + struct rds_ib_incoming *ibinc; + struct rds_page_frag *frag; + struct rds_page_frag *pos; + struct rds_ib_connection *ic = inc->i_conn->c_transport_data; + + ibinc = container_of(inc, struct rds_ib_incoming, ii_inc); + + /* Free attached frags */ + list_for_each_entry_safe(frag, pos, &ibinc->ii_frags, f_item) { + list_del_init(&frag->f_item); + rds_ib_frag_free(ic, frag); + } + BUG_ON(!list_empty(&ibinc->ii_frags)); + + rdsdebug("freeing ibinc %p inc %p\n", ibinc, inc); + rds_ib_recv_cache_put(&ibinc->ii_cache_entry, &ic->i_cache_incs); +} + static void rds_ib_recv_clear_one(struct rds_ib_connection *ic, struct rds_ib_recv_work *recv) { @@ -88,7 +225,7 @@ static void rds_ib_recv_clear_one(struct rds_ib_connection *ic, } if (recv->r_frag) { ib_dma_unmap_sg(ic->i_cm_id->device, &recv->r_frag->f_sg, 1, DMA_FROM_DEVICE); - rds_ib_frag_free(recv->r_frag); + rds_ib_frag_free(ic, recv->r_frag); recv->r_frag = NULL; } } @@ -101,6 +238,61 @@ void rds_ib_recv_clear_ring(struct rds_ib_connection *ic) rds_ib_recv_clear_one(ic, &ic->i_recvs[i]); } +static struct rds_ib_incoming *rds_ib_refill_one_inc(struct rds_ib_connection *ic) +{ + struct rds_ib_incoming *ibinc; + struct list_head *cache_item; + int avail_allocs; + + cache_item = rds_ib_recv_cache_get(&ic->i_cache_incs); + if (cache_item) { + ibinc = container_of(cache_item, struct rds_ib_incoming, ii_cache_entry); + } else { + avail_allocs = atomic_add_unless(&rds_ib_allocation, + 1, rds_ib_sysctl_max_recv_allocation); + if (!avail_allocs) { + rds_ib_stats_inc(s_ib_rx_alloc_limit); + return NULL; + } + ibinc = kmem_cache_alloc(rds_ib_incoming_slab, GFP_NOWAIT); + if (!ibinc) { + atomic_dec(&rds_ib_allocation); + return NULL; + } + } + INIT_LIST_HEAD(&ibinc->ii_frags); + rds_inc_init(&ibinc->ii_inc, ic->conn, ic->conn->c_faddr); + + return ibinc; +} + +static struct rds_page_frag *rds_ib_refill_one_frag(struct rds_ib_connection *ic) +{ + struct rds_page_frag *frag; + struct list_head *cache_item; + int ret; + + cache_item = rds_ib_recv_cache_get(&ic->i_cache_frags); + if (cache_item) { + frag = container_of(cache_item, struct rds_page_frag, f_cache_entry); + } else { + frag = kmem_cache_alloc(rds_ib_frag_slab, GFP_NOWAIT); + if (!frag) + return NULL; + + ret = rds_page_remainder_alloc(&frag->f_sg, + RDS_FRAG_SIZE, GFP_NOWAIT); + if (ret) { + kmem_cache_free(rds_ib_frag_slab, frag); + return NULL; + } + } + + INIT_LIST_HEAD(&frag->f_item); + + return frag; +} + static int rds_ib_recv_refill_one(struct rds_connection *conn, struct rds_ib_recv_work *recv) { @@ -108,37 +300,25 @@ static int rds_ib_recv_refill_one(struct rds_connection *conn, struct ib_sge *sge; int ret = -ENOMEM; + if (!ic->i_cache_incs.ready) + rds_ib_cache_xfer_to_ready(&ic->i_cache_incs); + if (!ic->i_cache_frags.ready) + rds_ib_cache_xfer_to_ready(&ic->i_cache_frags); + /* * ibinc was taken from recv if recv contained the start of a message. * recvs that were continuations will still have this allocated. */ if (!recv->r_ibinc) { - if (!atomic_add_unless(&rds_ib_allocation, 1, rds_ib_sysctl_max_recv_allocation)) { - rds_ib_stats_inc(s_ib_rx_alloc_limit); - goto out; - } - recv->r_ibinc = kmem_cache_alloc(rds_ib_incoming_slab, GFP_NOWAIT); - if (!recv->r_ibinc) { - atomic_dec(&rds_ib_allocation); + recv->r_ibinc = rds_ib_refill_one_inc(ic); + if (!recv->r_ibinc) goto out; - } - INIT_LIST_HEAD(&recv->r_ibinc->ii_frags); - rds_inc_init(&recv->r_ibinc->ii_inc, conn, conn->c_faddr); } WARN_ON(recv->r_frag); /* leak! */ - recv->r_frag = kmem_cache_alloc(rds_ib_frag_slab, GFP_NOWAIT); + recv->r_frag = rds_ib_refill_one_frag(ic); if (!recv->r_frag) goto out; - INIT_LIST_HEAD(&recv->r_frag->f_item); - sg_init_table(&recv->r_frag->f_sg, 1); - ret = rds_page_remainder_alloc(&recv->r_frag->f_sg, - RDS_FRAG_SIZE, GFP_NOWAIT); - if (ret) { - kmem_cache_free(rds_ib_frag_slab, recv->r_frag); - recv->r_frag = NULL; - goto out; - } ret = ib_dma_map_sg(ic->i_cm_id->device, &recv->r_frag->f_sg, 1, DMA_FROM_DEVICE); @@ -160,8 +340,7 @@ out: /* * This tries to allocate and post unused work requests after making sure that * they have all the allocations they need to queue received fragments into - * sockets. The i_recv_mutex is held here so that ring_alloc and _unalloc - * pairs don't go unmatched. + * sockets. * * -1 is returned if posting fails due to temporary resource exhaustion. */ @@ -216,33 +395,71 @@ int rds_ib_recv_refill(struct rds_connection *conn, int prefill) return ret; } -static void rds_ib_inc_purge(struct rds_incoming *inc) +/* + * We want to recycle several types of recv allocations, like incs and frags. + * To use this, the *_free() function passes in the ptr to a list_head within + * the recyclee, as well as the cache to put it on. + * + * First, we put the memory on a percpu list. When this reaches a certain size, + * We move it to an intermediate non-percpu list in a lockless manner, with some + * xchg/compxchg wizardry. + * + * N.B. Instead of a list_head as the anchor, we use a single pointer, which can + * be NULL and xchg'd. The list is actually empty when the pointer is NULL, and + * list_empty() will return true with one element is actually present. + */ +static void rds_ib_recv_cache_put(struct list_head *new_item, + struct rds_ib_refill_cache *cache) { - struct rds_ib_incoming *ibinc; - struct rds_page_frag *frag; - struct rds_page_frag *pos; + unsigned long flags; + struct rds_ib_cache_head *chp; + struct list_head *old; - ibinc = container_of(inc, struct rds_ib_incoming, ii_inc); - rdsdebug("purging ibinc %p inc %p\n", ibinc, inc); + local_irq_save(flags); - list_for_each_entry_safe(frag, pos, &ibinc->ii_frags, f_item) { - list_del_init(&frag->f_item); - rds_ib_frag_free(frag); - } + chp = per_cpu_ptr(cache->percpu, smp_processor_id()); + if (!chp->first) + INIT_LIST_HEAD(new_item); + else /* put on front */ + list_add_tail(new_item, chp->first); + chp->first = new_item; + chp->count++; + + if (chp->count < RDS_IB_RECYCLE_BATCH_COUNT) + goto end; + + /* + * Return our per-cpu first list to the cache's xfer by atomically + * grabbing the current xfer list, appending it to our per-cpu list, + * and then atomically returning that entire list back to the + * cache's xfer list as long as it's still empty. + */ + do { + old = xchg(&cache->xfer, NULL); + if (old) + list_splice_entire_tail(old, chp->first); + old = cmpxchg(&cache->xfer, NULL, chp->first); + } while (old); + + chp->first = NULL; + chp->count = 0; +end: + local_irq_restore(flags); } -void rds_ib_inc_free(struct rds_incoming *inc) +static struct list_head *rds_ib_recv_cache_get(struct rds_ib_refill_cache *cache) { - struct rds_ib_incoming *ibinc; - - ibinc = container_of(inc, struct rds_ib_incoming, ii_inc); + struct list_head *head = cache->ready; + + if (head) { + if (!list_empty(head)) { + cache->ready = head->next; + list_del_init(head); + } else + cache->ready = NULL; + } - rds_ib_inc_purge(inc); - rdsdebug("freeing ibinc %p inc %p\n", ibinc, inc); - BUG_ON(!list_empty(&ibinc->ii_frags)); - kmem_cache_free(rds_ib_incoming_slab, ibinc); - atomic_dec(&rds_ib_allocation); - BUG_ON(atomic_read(&rds_ib_allocation) < 0); + return head; } int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov, @@ -647,7 +864,7 @@ static void rds_ib_process_recv(struct rds_connection *conn, * * FIXME: Fold this into the code path below. */ - rds_ib_frag_free(recv->r_frag); + rds_ib_frag_free(ic, recv->r_frag); recv->r_frag = NULL; return; } |
