From 9c584f04959620e587b3b3d358076dab48a8893c Mon Sep 17 00:00:00 2001 From: Matan Barak Date: Wed, 28 Oct 2015 16:52:40 +0200 Subject: [PATCH] IB/core: Change per-entry lock in RoCE GID table to one lock Previously, IB GID cached used a lock per entry. This could result in spending a lot of CPU cycles for locking and unlocking just in order to find a GID. Changing this in favor of one lock per a GID table. Signed-off-by: Matan Barak Reviewed-by: Haggai Eran Signed-off-by: Doug Ledford --- drivers/infiniband/core/cache.c | 143 ++++++++++++++++++++------------ 1 file changed, 89 insertions(+), 54 deletions(-) diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c index f0703d22ff98..83aee7c55cb3 100644 --- a/drivers/infiniband/core/cache.c +++ b/drivers/infiniband/core/cache.c @@ -81,10 +81,6 @@ enum gid_table_write_action { }; struct ib_gid_table_entry { - /* This lock protects an entry from being - * read and written simultaneously. - */ - rwlock_t lock; unsigned long props; union ib_gid gid; struct ib_gid_attr attr; @@ -109,6 +105,10 @@ struct ib_gid_table { * are locked by this lock. **/ struct mutex lock; + /* This lock protects the table entries from being + * read and written simultaneously. + */ + rwlock_t rwlock; struct ib_gid_table_entry *data_vec; }; @@ -125,6 +125,10 @@ static void dispatch_gid_change_event(struct ib_device *ib_dev, u8 port) } } +/* This function expects that rwlock will be write locked in all + * scenarios and that lock will be locked in sleep-able (RoCE) + * scenarios. + */ static int write_gid(struct ib_device *ib_dev, u8 port, struct ib_gid_table *table, int ix, const union ib_gid *gid, @@ -134,16 +138,14 @@ static int write_gid(struct ib_device *ib_dev, u8 port, { int ret = 0; struct net_device *old_net_dev; - unsigned long flags; /* in rdma_cap_roce_gid_table, this funciton should be protected by a * sleep-able lock. */ - write_lock_irqsave(&table->data_vec[ix].lock, flags); if (rdma_cap_roce_gid_table(ib_dev, port)) { table->data_vec[ix].props |= GID_TABLE_ENTRY_INVALID; - write_unlock_irqrestore(&table->data_vec[ix].lock, flags); + write_unlock_irq(&table->rwlock); /* GID_TABLE_WRITE_ACTION_MODIFY currently isn't supported by * RoCE providers and thus only updates the cache. */ @@ -153,7 +155,7 @@ static int write_gid(struct ib_device *ib_dev, u8 port, else if (action == GID_TABLE_WRITE_ACTION_DEL) ret = ib_dev->del_gid(ib_dev, port, ix, &table->data_vec[ix].context); - write_lock_irqsave(&table->data_vec[ix].lock, flags); + write_lock_irq(&table->rwlock); } old_net_dev = table->data_vec[ix].attr.ndev; @@ -175,11 +177,6 @@ static int write_gid(struct ib_device *ib_dev, u8 port, table->data_vec[ix].props &= ~GID_TABLE_ENTRY_INVALID; - write_unlock_irqrestore(&table->data_vec[ix].lock, flags); - - if (!ret) - dispatch_gid_change_event(ib_dev, port); - return ret; } @@ -208,6 +205,7 @@ static int del_gid(struct ib_device *ib_dev, u8 port, GID_TABLE_WRITE_ACTION_DEL, default_gid); } +/* rwlock should be read locked */ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid, const struct ib_gid_attr *val, bool default_gid, unsigned long mask) @@ -215,34 +213,29 @@ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid, int i; for (i = 0; i < table->sz; i++) { - unsigned long flags; struct ib_gid_attr *attr = &table->data_vec[i].attr; - read_lock_irqsave(&table->data_vec[i].lock, flags); if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID) - goto next; + continue; if (mask & GID_ATTR_FIND_MASK_GID && memcmp(gid, &table->data_vec[i].gid, sizeof(*gid))) - goto next; + continue; if (mask & GID_ATTR_FIND_MASK_NETDEV && attr->ndev != val->ndev) - goto next; + continue; if (mask & GID_ATTR_FIND_MASK_DEFAULT && !!(table->data_vec[i].props & GID_TABLE_ENTRY_DEFAULT) != default_gid) - goto next; + continue; - read_unlock_irqrestore(&table->data_vec[i].lock, flags); - return i; -next: - read_unlock_irqrestore(&table->data_vec[i].lock, flags); + break; } - return -1; + return i == table->sz ? -1 : i; } static void make_default_gid(struct net_device *dev, union ib_gid *gid) @@ -282,6 +275,7 @@ int ib_cache_gid_add(struct ib_device *ib_dev, u8 port, } mutex_lock(&table->lock); + write_lock_irq(&table->rwlock); ix = find_gid(table, gid, attr, false, GID_ATTR_FIND_MASK_GID | GID_ATTR_FIND_MASK_NETDEV); @@ -295,9 +289,12 @@ int ib_cache_gid_add(struct ib_device *ib_dev, u8 port, goto out_unlock; } - add_gid(ib_dev, port, table, ix, gid, attr, false); + ret = add_gid(ib_dev, port, table, ix, gid, attr, false); + if (!ret) + dispatch_gid_change_event(ib_dev, port); out_unlock: + write_unlock_irq(&table->rwlock); mutex_unlock(&table->lock); return ret; } @@ -312,6 +309,7 @@ int ib_cache_gid_del(struct ib_device *ib_dev, u8 port, table = ports_table[port - rdma_start_port(ib_dev)]; mutex_lock(&table->lock); + write_lock_irq(&table->rwlock); ix = find_gid(table, gid, attr, false, GID_ATTR_FIND_MASK_GID | @@ -320,9 +318,11 @@ int ib_cache_gid_del(struct ib_device *ib_dev, u8 port, if (ix < 0) goto out_unlock; - del_gid(ib_dev, port, table, ix, false); + if (!del_gid(ib_dev, port, table, ix, false)) + dispatch_gid_change_event(ib_dev, port); out_unlock: + write_unlock_irq(&table->rwlock); mutex_unlock(&table->lock); return 0; } @@ -333,16 +333,24 @@ int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u8 port, struct ib_gid_table **ports_table = ib_dev->cache.gid_cache; struct ib_gid_table *table; int ix; + bool deleted = false; table = ports_table[port - rdma_start_port(ib_dev)]; mutex_lock(&table->lock); + write_lock_irq(&table->rwlock); for (ix = 0; ix < table->sz; ix++) if (table->data_vec[ix].attr.ndev == ndev) - del_gid(ib_dev, port, table, ix, false); + if (!del_gid(ib_dev, port, table, ix, false)) + deleted = true; + write_unlock_irq(&table->rwlock); mutex_unlock(&table->lock); + + if (deleted) + dispatch_gid_change_event(ib_dev, port); + return 0; } @@ -351,18 +359,14 @@ static int __ib_cache_gid_get(struct ib_device *ib_dev, u8 port, int index, { struct ib_gid_table **ports_table = ib_dev->cache.gid_cache; struct ib_gid_table *table; - unsigned long flags; table = ports_table[port - rdma_start_port(ib_dev)]; if (index < 0 || index >= table->sz) return -EINVAL; - read_lock_irqsave(&table->data_vec[index].lock, flags); - if (table->data_vec[index].props & GID_TABLE_ENTRY_INVALID) { - read_unlock_irqrestore(&table->data_vec[index].lock, flags); + if (table->data_vec[index].props & GID_TABLE_ENTRY_INVALID) return -EAGAIN; - } memcpy(gid, &table->data_vec[index].gid, sizeof(*gid)); if (attr) { @@ -371,7 +375,6 @@ static int __ib_cache_gid_get(struct ib_device *ib_dev, u8 port, int index, dev_hold(attr->ndev); } - read_unlock_irqrestore(&table->data_vec[index].lock, flags); return 0; } @@ -385,17 +388,21 @@ static int _ib_cache_gid_table_find(struct ib_device *ib_dev, struct ib_gid_table *table; u8 p; int local_index; + unsigned long flags; for (p = 0; p < ib_dev->phys_port_cnt; p++) { table = ports_table[p]; + read_lock_irqsave(&table->rwlock, flags); local_index = find_gid(table, gid, val, false, mask); if (local_index >= 0) { if (index) *index = local_index; if (port) *port = p + rdma_start_port(ib_dev); + read_unlock_irqrestore(&table->rwlock, flags); return 0; } + read_unlock_irqrestore(&table->rwlock, flags); } return -ENOENT; @@ -426,6 +433,7 @@ int ib_find_cached_gid_by_port(struct ib_device *ib_dev, struct ib_gid_table *table; unsigned long mask = GID_ATTR_FIND_MASK_GID; struct ib_gid_attr val = {.ndev = ndev}; + unsigned long flags; if (port < rdma_start_port(ib_dev) || port > rdma_end_port(ib_dev)) @@ -436,13 +444,16 @@ int ib_find_cached_gid_by_port(struct ib_device *ib_dev, if (ndev) mask |= GID_ATTR_FIND_MASK_NETDEV; + read_lock_irqsave(&table->rwlock, flags); local_index = find_gid(table, gid, &val, false, mask); if (local_index >= 0) { if (index) *index = local_index; + read_unlock_irqrestore(&table->rwlock, flags); return 0; } + read_unlock_irqrestore(&table->rwlock, flags); return -ENOENT; } EXPORT_SYMBOL(ib_find_cached_gid_by_port); @@ -479,6 +490,7 @@ static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev, struct ib_gid_table **ports_table = ib_dev->cache.gid_cache; struct ib_gid_table *table; unsigned int i; + unsigned long flags; bool found = false; if (!ports_table) @@ -491,11 +503,10 @@ static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev, table = ports_table[port - rdma_start_port(ib_dev)]; + read_lock_irqsave(&table->rwlock, flags); for (i = 0; i < table->sz; i++) { struct ib_gid_attr attr; - unsigned long flags; - read_lock_irqsave(&table->data_vec[i].lock, flags); if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID) goto next; @@ -508,11 +519,10 @@ static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev, found = true; next: - read_unlock_irqrestore(&table->data_vec[i].lock, flags); - if (found) break; } + read_unlock_irqrestore(&table->rwlock, flags); if (!found) return -ENOENT; @@ -524,9 +534,9 @@ static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev, static struct ib_gid_table *alloc_gid_table(int sz) { - unsigned int i; struct ib_gid_table *table = kzalloc(sizeof(struct ib_gid_table), GFP_KERNEL); + if (!table) return NULL; @@ -537,9 +547,7 @@ static struct ib_gid_table *alloc_gid_table(int sz) mutex_init(&table->lock); table->sz = sz; - - for (i = 0; i < sz; i++) - rwlock_init(&table->data_vec[i].lock); + rwlock_init(&table->rwlock); return table; @@ -560,17 +568,24 @@ static void cleanup_gid_table_port(struct ib_device *ib_dev, u8 port, struct ib_gid_table *table) { int i; + bool deleted = false; if (!table) return; + write_lock_irq(&table->rwlock); for (i = 0; i < table->sz; ++i) { if (memcmp(&table->data_vec[i].gid, &zgid, sizeof(table->data_vec[i].gid))) - del_gid(ib_dev, port, table, i, - table->data_vec[i].props & - GID_ATTR_FIND_MASK_DEFAULT); + if (!del_gid(ib_dev, port, table, i, + table->data_vec[i].props & + GID_ATTR_FIND_MASK_DEFAULT)) + deleted = true; } + write_unlock_irq(&table->rwlock); + + if (deleted) + dispatch_gid_change_event(ib_dev, port); } void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port, @@ -592,6 +607,7 @@ void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port, gid_attr.ndev = ndev; mutex_lock(&table->lock); + write_lock_irq(&table->rwlock); ix = find_gid(table, NULL, NULL, true, GID_ATTR_FIND_MASK_DEFAULT); /* Coudn't find default GID location */ @@ -604,23 +620,31 @@ void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port, !memcmp(&gid_attr, ¤t_gid_attr, sizeof(gid_attr))) goto unlock; - if ((memcmp(¤t_gid, &zgid, sizeof(current_gid)) || - memcmp(¤t_gid_attr, &zattr, - sizeof(current_gid_attr))) && - del_gid(ib_dev, port, table, ix, true)) { - pr_warn("ib_cache_gid: can't delete index %d for default gid %pI6\n", - ix, gid.raw); - goto unlock; + if (memcmp(¤t_gid, &zgid, sizeof(current_gid)) || + memcmp(¤t_gid_attr, &zattr, + sizeof(current_gid_attr))) { + if (del_gid(ib_dev, port, table, ix, true)) { + pr_warn("ib_cache_gid: can't delete index %d for default gid %pI6\n", + ix, gid.raw); + goto unlock; + } else { + dispatch_gid_change_event(ib_dev, port); + } } - if (mode == IB_CACHE_GID_DEFAULT_MODE_SET) - if (add_gid(ib_dev, port, table, ix, &gid, &gid_attr, true)) + if (mode == IB_CACHE_GID_DEFAULT_MODE_SET) { + if (add_gid(ib_dev, port, table, ix, &gid, &gid_attr, true)) { pr_warn("ib_cache_gid: unable to add default gid %pI6\n", gid.raw); + } else { + dispatch_gid_change_event(ib_dev, port); + } + } unlock: if (current_gid_attr.ndev) dev_put(current_gid_attr.ndev); + write_unlock_irq(&table->rwlock); mutex_unlock(&table->lock); } @@ -735,10 +759,19 @@ int ib_get_cached_gid(struct ib_device *device, union ib_gid *gid, struct ib_gid_attr *gid_attr) { + int res; + unsigned long flags; + struct ib_gid_table **ports_table = device->cache.gid_cache; + struct ib_gid_table *table = ports_table[port_num - rdma_start_port(device)]; + if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device)) return -EINVAL; - return __ib_cache_gid_get(device, port_num, index, gid, gid_attr); + read_lock_irqsave(&table->rwlock, flags); + res = __ib_cache_gid_get(device, port_num, index, gid, gid_attr); + read_unlock_irqrestore(&table->rwlock, flags); + + return res; } EXPORT_SYMBOL(ib_get_cached_gid); @@ -963,10 +996,12 @@ static void ib_cache_update(struct ib_device *device, device->cache.pkey_cache[port - rdma_start_port(device)] = pkey_cache; if (!use_roce_gid_table) { + write_lock(&table->rwlock); for (i = 0; i < gid_cache->table_len; i++) { modify_gid(device, port, table, i, gid_cache->table + i, &zattr, false); } + write_unlock(&table->rwlock); } device->cache.lmc_cache[port - rdma_start_port(device)] = tprops->lmc; -- GitLab