From patchwork Wed Aug 10 17:47:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940857 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DAC9C25B0D for ; Wed, 10 Aug 2022 17:47:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232338AbiHJRrt (ORCPT ); Wed, 10 Aug 2022 13:47:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232274AbiHJRrs (ORCPT ); Wed, 10 Aug 2022 13:47:48 -0400 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 058D786C06; Wed, 10 Aug 2022 10:47:45 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R881e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvmsHN_1660153662; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvmsHN_1660153662) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:43 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 01/10] net/smc: remove locks smc_client_lgr_pending and smc_server_lgr_pending Date: Thu, 11 Aug 2022 01:47:32 +0800 Message-Id: <075ff0be35660efac638448cdae7f7e7e04199d4.1660152975.git.alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" This patch attempts to remove locks named smc_client_lgr_pending and smc_server_lgr_pending, which aim to serialize the creation of link group. However, once link group existed already, those locks are meaningless, worse still, they make incoming connections have to be queued one after the other. Now, the creation of link group is no longer generated by competition, but allocated through following strategy. 1. Try to find a suitable link group, if successd, current connection is considered as NON first contact connection. ends. 2. Check the number of connections currently waiting for a suitable link group to be created, if it is not less that the number of link groups to be created multiplied by (SMC_RMBS_PER_LGR_MAX - 1), then increase the number of link groups to be created, current connection is considered as the first contact connection. ends. 3. Increase the number of connections currently waiting, and wait for woken up. 4. Decrease the number of connections currently waiting, goto 1. We wake up the connection that was put to sleep in stage 3 through the SMC link state change event. Once the link moves out of the SMC_LNK_ACTIVATING state, decrease the number of link groups to be created, and then wake up at most (SMC_RMBS_PER_LGR_MAX - 1) connections. In the iplementation, we introduce the concept of lnk cluster, which is a collection of links with the same characteristics (see smcr_lnk_cluster_cmpfn() with more details), which makes it possible to wake up efficiently in the scenario of N v.s 1. Signed-off-by: D. Wythe Reported-by: kernel test robot Reported-by: kernel test robot --- net/smc/af_smc.c | 11 +- net/smc/smc_core.c | 356 ++++++++++++++++++++++++++++++++++++++++++++++++++++- net/smc/smc_core.h | 48 ++++++++ net/smc/smc_llc.c | 9 +- 4 files changed, 411 insertions(+), 13 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 79c1318..af4b0aa 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1194,10 +1194,8 @@ static int smc_connect_rdma(struct smc_sock *smc, if (reason_code) return reason_code; - mutex_lock(&smc_client_lgr_pending); reason_code = smc_conn_create(smc, ini); if (reason_code) { - mutex_unlock(&smc_client_lgr_pending); return reason_code; } @@ -1289,7 +1287,6 @@ static int smc_connect_rdma(struct smc_sock *smc, if (reason_code) goto connect_abort; } - mutex_unlock(&smc_client_lgr_pending); smc_copy_sock_settings_to_clc(smc); smc->connect_nonblock = 0; @@ -1299,7 +1296,6 @@ static int smc_connect_rdma(struct smc_sock *smc, return 0; connect_abort: smc_conn_abort(smc, ini->first_contact_local); - mutex_unlock(&smc_client_lgr_pending); smc->connect_nonblock = 0; return reason_code; @@ -2377,7 +2373,8 @@ static void smc_listen_work(struct work_struct *work) if (rc) goto out_decl; - mutex_lock(&smc_server_lgr_pending); + if (ini->is_smcd) + mutex_lock(&smc_server_lgr_pending); smc_close_init(new_smc); smc_rx_init(new_smc); smc_tx_init(new_smc); @@ -2415,7 +2412,6 @@ static void smc_listen_work(struct work_struct *work) ini->first_contact_local, ini); if (rc) goto out_unlock; - mutex_unlock(&smc_server_lgr_pending); } smc_conn_save_peer_info(new_smc, cclc); smc_listen_out_connected(new_smc); @@ -2423,7 +2419,8 @@ static void smc_listen_work(struct work_struct *work) goto out_free; out_unlock: - mutex_unlock(&smc_server_lgr_pending); + if (ini->is_smcd) + mutex_unlock(&smc_server_lgr_pending); out_decl: smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0, proposal_version); diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index ff49a11..a3338cc 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -46,6 +46,10 @@ struct smc_lgr_list smc_lgr_list = { /* established link groups */ .num = 0, }; +struct smc_lgr_manager smc_lgr_manager = { + .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_manager.lock), +}; + static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */ static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted); @@ -55,6 +59,282 @@ static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb, static void smc_link_down_work(struct work_struct *work); +/* SMC-R lnk cluster compare func + * All lnks that meet the description conditions of this function + * are logically aggregated, called lnk cluster. + * For the server side, lnk cluster is used to determine whether + * a new group needs to be created when processing new imcoming connections. + * For the client side, lnk cluster is used to determine whether + * to wait for link ready (in other words, first contact ready). + */ +static int smcr_lnk_cluster_cmpfn(struct rhashtable_compare_arg *arg, const void *obj) +{ + const struct smc_lnk_cluster_compare_arg *key = arg->key; + const struct smc_lnk_cluster *lnkc = obj; + + if (memcmp(key->peer_systemid, lnkc->peer_systemid, SMC_SYSTEMID_LEN)) + return 1; + + if (memcmp(key->peer_gid, lnkc->peer_gid, SMC_GID_SIZE)) + return 1; + + if ((key->role == SMC_SERV || key->clcqpn == lnkc->clcqpn) && + (key->smcr_version == SMC_V2 || + !memcmp(key->peer_mac, lnkc->peer_mac, ETH_ALEN))) + return 0; + + return 1; +} + +/* SMC-R lnk cluster hash func */ +static u32 smcr_lnk_cluster_hashfn(const void *data, u32 len, u32 seed) +{ + const struct smc_lnk_cluster *lnkc = data; + + return jhash2((u32 *)lnkc->peer_systemid, SMC_SYSTEMID_LEN / sizeof(u32), seed) + + (lnkc->role == SMC_SERV) ? 0 : lnkc->clcqpn; +} + +/* SMC-R lnk cluster compare arg hash func */ +static u32 smcr_lnk_cluster_compare_arg_hashfn(const void *data, u32 len, u32 seed) +{ + const struct smc_lnk_cluster_compare_arg *key = data; + + return jhash2((u32 *)key->peer_systemid, SMC_SYSTEMID_LEN / sizeof(u32), seed) + + (key->role == SMC_SERV) ? 0 : key->clcqpn; +} + +static const struct rhashtable_params smcr_lnk_cluster_rhl_params = { + .head_offset = offsetof(struct smc_lnk_cluster, rnode), + .key_len = sizeof(struct smc_lnk_cluster_compare_arg), + .obj_cmpfn = smcr_lnk_cluster_cmpfn, + .obj_hashfn = smcr_lnk_cluster_hashfn, + .hashfn = smcr_lnk_cluster_compare_arg_hashfn, + .automatic_shrinking = true, +}; + +/* hold a reference for smc_lnk_cluster */ +static inline void smc_lnk_cluster_hold(struct smc_lnk_cluster *lnkc) +{ + if (likely(lnkc)) + refcount_inc(&lnkc->ref); +} + +/* release a reference for smc_lnk_cluster */ +static inline void smc_lnk_cluster_put(struct smc_lnk_cluster *lnkc) +{ + bool do_free = false; + + if (!lnkc) + return; + + if (refcount_dec_not_one(&lnkc->ref)) + return; + + spin_lock_bh(&smc_lgr_manager.lock); + /* last ref */ + if (refcount_dec_and_test(&lnkc->ref)) { + do_free = true; + rhashtable_remove_fast(&smc_lgr_manager.lnk_cluster_maps, &lnkc->rnode, + smcr_lnk_cluster_rhl_params); + } + spin_unlock_bh(&smc_lgr_manager.lock); + if (do_free) + kfree(lnkc); +} + +/* Get or create smc_lnk_cluster by key + * This function will hold a reference of returned smc_lnk_cluster + * or create a new smc_lnk_cluster with the reference initialized to 1。 + * caller MUST call smc_lnk_cluster_put after this. + */ +static inline struct smc_lnk_cluster * +smcr_lnk_get_or_create_cluster(struct smc_lnk_cluster_compare_arg *key) +{ + struct smc_lnk_cluster *lnkc, *tmp_lnkc; + bool busy_retry; + int err; + + /* serving a hardware or software interrupt, or preemption is disabled */ + busy_retry = !in_interrupt(); + + spin_lock_bh(&smc_lgr_manager.lock); + lnkc = rhashtable_lookup_fast(&smc_lgr_manager.lnk_cluster_maps, key, + smcr_lnk_cluster_rhl_params); + if (!lnkc) { + lnkc = kzalloc(sizeof(*lnkc), GFP_ATOMIC); + if (unlikely(!lnkc)) + goto fail; + + /* init cluster */ + spin_lock_init(&lnkc->lock); + lnkc->role = key->role; + if (key->role == SMC_CLNT) + lnkc->clcqpn = key->clcqpn; + init_waitqueue_head(&lnkc->first_contact_waitqueue); + memcpy(lnkc->peer_systemid, key->peer_systemid, SMC_SYSTEMID_LEN); + memcpy(lnkc->peer_gid, key->peer_gid, SMC_GID_SIZE); + memcpy(lnkc->peer_mac, key->peer_mac, ETH_ALEN); + refcount_set(&lnkc->ref, 1); + + do { + err = rhashtable_insert_fast(&smc_lgr_manager.lnk_cluster_maps, + &lnkc->rnode, smcr_lnk_cluster_rhl_params); + + /* success or fatal error */ + if (err != -EBUSY) + break; + + /* impossible in fact right now */ + if (unlikely(!busy_retry)) { + pr_warn_ratelimited("smc: create lnk cluster in softirq\n"); + break; + } + + spin_unlock_bh(&smc_lgr_manager.lock); + /* yeild */ + cond_resched(); + spin_lock_bh(&smc_lgr_manager.lock); + + /* after spin_unlock_bh(), lnk_cluster_maps may be changed */ + tmp_lnkc = rhashtable_lookup_fast(&smc_lgr_manager.lnk_cluster_maps, key, + smcr_lnk_cluster_rhl_params); + + if (unlikely(tmp_lnkc)) { + pr_warn_ratelimited("smc: create cluster failed dues to duplicat key"); + kfree(lnkc); + lnkc = NULL; + goto fail; + } + } while (1); + + if (unlikely(err)) { + pr_warn_ratelimited("smc: rhashtable_insert_fast failed (%d)", err); + kfree(lnkc); + lnkc = NULL; + } + } else { + smc_lnk_cluster_hold(lnkc); + } +fail: + spin_unlock_bh(&smc_lgr_manager.lock); + return lnkc; +} + +/* Get or create a smc_lnk_cluster by lnk + * caller MUST call smc_lnk_cluster_put after this. + */ +static inline struct smc_lnk_cluster *smcr_lnk_get_cluster(struct smc_link *lnk) +{ + struct smc_lnk_cluster_compare_arg key; + struct smc_link_group *lgr; + + lgr = lnk->lgr; + if (!lgr || lgr->is_smcd) + return NULL; + + key.smcr_version = lgr->smc_version; + key.peer_systemid = lgr->peer_systemid; + key.peer_gid = lnk->peer_gid; + key.peer_mac = lnk->peer_mac; + key.role = lgr->role; + if (key.role == SMC_CLNT) + key.clcqpn = lnk->peer_qpn; + + return smcr_lnk_get_or_create_cluster(&key); +} + +/* Get or create a smc_lnk_cluster by ini + * caller MUST call smc_lnk_cluster_put after this. + */ +static inline struct smc_lnk_cluster * +smcr_lnk_get_cluster_by_ini(struct smc_init_info *ini, int role) +{ + struct smc_lnk_cluster_compare_arg key; + + if (ini->is_smcd) + return NULL; + + key.smcr_version = ini->smcr_version; + key.peer_systemid = ini->peer_systemid; + key.peer_gid = ini->peer_gid; + key.peer_mac = ini->peer_mac; + key.role = role; + if (role == SMC_CLNT) + key.clcqpn = ini->ib_clcqpn; + + return smcr_lnk_get_or_create_cluster(&key); +} + +/* callback when smc link state change */ +void smcr_lnk_cluster_on_lnk_state(struct smc_link *lnk) +{ + struct smc_lnk_cluster *lnkc; + int nr = 0; + + /* barrier for lnk->state */ + smp_mb(); + + /* only first link can made connections block on + * first_contact_waitqueue + */ + if (lnk->link_idx != SMC_SINGLE_LINK) + return; + + /* state already seen */ + if (lnk->state_record & SMC_LNK_STATE_BIT(lnk->state)) + return; + + lnkc = smcr_lnk_get_cluster(lnk); + + if (unlikely(!lnkc)) + return; + + spin_lock_bh(&lnkc->lock); + + /* all lnk state change should be + * 1. SMC_LNK_UNUSED -> SMC_LNK_TEAR_DWON (link init failed) + * 2. SMC_LNK_UNUSED -> SMC_LNK_ACTIVATING -> SMC_LNK_TEAR_DWON + * 3. SMC_LNK_UNUSED -> SMC_LNK_ACTIVATING -> SMC_LNK_INACTIVE -> SMC_LNK_TEAR_DWON + * 4. SMC_LNK_UNUSED -> SMC_LNK_ACTIVATING -> SMC_LNK_INACTIVE -> SMC_LNK_TEAR_DWON + * 5. SMC_LNK_UNUSED -> SMC_LNK_ATIVATING -> SMC_LNK_ACTIVE ->SMC_LNK_INACTIVE + * -> SMC_LNK_TEAR_DWON + */ + switch (lnk->state) { + case SMC_LNK_ACTIVATING: + /* It's safe to hold a reference without lock + * dues to the smcr_lnk_get_cluster already hold one + */ + smc_lnk_cluster_hold(lnkc); + break; + case SMC_LNK_TEAR_DWON: + if (lnk->state_record & SMC_LNK_STATE_BIT(SMC_LNK_ACTIVATING)) + /* smc_lnk_cluster_hold in SMC_LNK_ACTIVATING */ + smc_lnk_cluster_put(lnkc); + fallthrough; + case SMC_LNK_ACTIVE: + case SMC_LNK_INACTIVE: + if (!(lnk->state_record & + (SMC_LNK_STATE_BIT(SMC_LNK_ACTIVE) + | SMC_LNK_STATE_BIT(SMC_LNK_INACTIVE)))) { + lnkc->pending_capability -= (SMC_RMBS_PER_LGR_MAX - 1); + /* TODO: wakeup just one to perfrom first contact + * if record state has no SMC_LNK_ACTIVE + */ + nr = SMC_RMBS_PER_LGR_MAX - 1; + } + break; + case SMC_LNK_UNUSED: + pr_warn_ratelimited("net/smc: invalid lnk state. "); + break; + } + SMC_LNK_STATE_RECORD(lnk, lnk->state); + spin_unlock_bh(&lnkc->lock); + if (nr) + wake_up_nr(&lnkc->first_contact_waitqueue, nr); + smc_lnk_cluster_put(lnkc); /* smc_lnk_cluster_hold in smcr_lnk_get_cluster */ +} + /* return head of link group list and its lock for a given link group */ static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr, spinlock_t **lgr_lock) @@ -651,8 +931,10 @@ static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr) for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { struct smc_link *lnk = &lgr->lnk[i]; - if (smc_link_sendable(lnk)) + if (smc_link_sendable(lnk)) { lnk->state = SMC_LNK_INACTIVE; + smcr_lnk_cluster_on_lnk_state(lnk); + } } wake_up_all(&lgr->llc_msg_waiter); wake_up_all(&lgr->llc_flow_waiter); @@ -762,6 +1044,9 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, atomic_set(&lnk->conn_cnt, 0); smc_llc_link_set_uid(lnk); INIT_WORK(&lnk->link_down_wrk, smc_link_down_work); + lnk->peer_qpn = ini->ib_clcqpn; + memcpy(lnk->peer_gid, ini->peer_gid, SMC_GID_SIZE); + memcpy(lnk->peer_mac, ini->peer_mac, sizeof(lnk->peer_mac)); if (!lnk->smcibdev->initialized) { rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev); if (rc) @@ -792,6 +1077,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, if (rc) goto destroy_qp; lnk->state = SMC_LNK_ACTIVATING; + smcr_lnk_cluster_on_lnk_state(lnk); return 0; destroy_qp: @@ -806,6 +1092,8 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, smc_ibdev_cnt_dec(lnk); put_device(&lnk->smcibdev->ibdev->dev); smcibdev = lnk->smcibdev; + lnk->state = SMC_LNK_TEAR_DWON; + smcr_lnk_cluster_on_lnk_state(lnk); memset(lnk, 0, sizeof(struct smc_link)); lnk->state = SMC_LNK_UNUSED; if (!atomic_dec_return(&smcibdev->lnk_cnt)) @@ -1263,6 +1551,8 @@ void smcr_link_clear(struct smc_link *lnk, bool log) if (!lnk->lgr || lnk->clearing || lnk->state == SMC_LNK_UNUSED) return; + lnk->state = SMC_LNK_TEAR_DWON; + smcr_lnk_cluster_on_lnk_state(lnk); lnk->clearing = 1; lnk->peer_qpn = 0; smc_llc_link_clear(lnk, log); @@ -1712,6 +2002,7 @@ void smcr_link_down_cond(struct smc_link *lnk) { if (smc_link_downing(&lnk->state)) { trace_smcr_link_down(lnk, __builtin_return_address(0)); + smcr_lnk_cluster_on_lnk_state(lnk); smcr_link_down(lnk); } } @@ -1721,6 +2012,7 @@ void smcr_link_down_cond_sched(struct smc_link *lnk) { if (smc_link_downing(&lnk->state)) { trace_smcr_link_down(lnk, __builtin_return_address(0)); + smcr_lnk_cluster_on_lnk_state(lnk); schedule_work(&lnk->link_down_wrk); } } @@ -1850,11 +2142,13 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) { struct smc_connection *conn = &smc->conn; struct net *net = sock_net(&smc->sk); + DECLARE_WAITQUEUE(wait, current); + struct smc_lnk_cluster *lnkc = NULL; struct list_head *lgr_list; struct smc_link_group *lgr; enum smc_lgr_role role; spinlock_t *lgr_lock; - int rc = 0; + int rc = 0, timeo = CLC_WAIT_TIME; lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list : &smc_lgr_list.list; @@ -1862,12 +2156,26 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) &smc_lgr_list.lock; ini->first_contact_local = 1; role = smc->listen_smc ? SMC_SERV : SMC_CLNT; - if (role == SMC_CLNT && ini->first_contact_peer) + + if (!ini->is_smcd) { + lnkc = smcr_lnk_get_cluster_by_ini(ini, role); + if (unlikely(!lnkc)) + return SMC_CLC_DECL_INTERR; + } + + if (role == SMC_CLNT && ini->first_contact_peer) { + /* first_contact */ + spin_lock_bh(&lnkc->lock); + lnkc->pending_capability += (SMC_RMBS_PER_LGR_MAX - 1); + spin_unlock_bh(&lnkc->lock); /* create new link group as well */ goto create; + } /* determine if an existing link group can be reused */ spin_lock_bh(lgr_lock); + spin_lock(&lnkc->lock); +again: list_for_each_entry(lgr, lgr_list, list) { write_lock_bh(&lgr->conns_lock); if ((ini->is_smcd ? @@ -1894,9 +2202,33 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) } write_unlock_bh(&lgr->conns_lock); } + if (lnkc && ini->first_contact_local) { + if (lnkc->pending_capability > lnkc->conns_pending) { + lnkc->conns_pending++; + add_wait_queue(&lnkc->first_contact_waitqueue, &wait); + spin_unlock(&lnkc->lock); + spin_unlock_bh(lgr_lock); + set_current_state(TASK_INTERRUPTIBLE); + /* need to wait at least once first contact done */ + timeo = schedule_timeout(timeo); + set_current_state(TASK_RUNNING); + remove_wait_queue(&lnkc->first_contact_waitqueue, &wait); + spin_lock_bh(lgr_lock); + spin_lock(&lnkc->lock); + + lnkc->conns_pending--; + if (timeo) + goto again; + } + if (role == SMC_SERV) { + /* first_contact */ + lnkc->pending_capability += (SMC_RMBS_PER_LGR_MAX - 1); + } + } + spin_unlock(&lnkc->lock); spin_unlock_bh(lgr_lock); if (rc) - return rc; + goto out; if (role == SMC_CLNT && !ini->first_contact_peer && ini->first_contact_local) { @@ -1904,7 +2236,8 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) * a new one * send out_of_sync decline, reason synchr. error */ - return SMC_CLC_DECL_SYNCERR; + rc = SMC_CLC_DECL_SYNCERR; + goto out; } create: @@ -1941,6 +2274,8 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) #endif out: + /* smc_lnk_cluster_hold in smcr_lnk_get_or_create_cluster */ + smc_lnk_cluster_put(lnkc); return rc; } @@ -2599,12 +2934,23 @@ static int smc_core_reboot_event(struct notifier_block *this, int __init smc_core_init(void) { + /* init smc lnk cluster maps */ + rhashtable_init(&smc_lgr_manager.lnk_cluster_maps, &smcr_lnk_cluster_rhl_params); return register_reboot_notifier(&smc_reboot_notifier); } +static void smc_lnk_cluster_free_cb(void *ptr, void *arg) +{ + pr_warn("smc: smc lnk cluster refcnt leak.\n"); + kfree(ptr); +} + /* Called (from smc_exit) when module is removed */ void smc_core_exit(void) { unregister_reboot_notifier(&smc_reboot_notifier); smc_lgrs_shutdown(); + /* destroy smc lnk cluster maps */ + rhashtable_free_and_destroy(&smc_lgr_manager.lnk_cluster_maps, smc_lnk_cluster_free_cb, + NULL); } diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index fe8b524..199f533 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -29,18 +30,62 @@ struct smc_lgr_list { /* list of link group definition */ u32 num; /* unique link group number */ }; +struct smc_lgr_manager { /* manager for link group */ + struct rhashtable lnk_cluster_maps; /* maps of smc_lnk_cluster */ + spinlock_t lock; /* lock for lgr_cm_maps */ +}; + +struct smc_lnk_cluster { + struct rhash_head rnode; /* node for rhashtable */ + struct wait_queue_head first_contact_waitqueue; + /* queue for non first contact to wait + * first contact to be established. + */ + spinlock_t lock; /* protection for link group */ + refcount_t ref; /* refcount for cluster */ + unsigned long pending_capability; + /* maximum pending number of connections that + * need wait first contact complete. + */ + unsigned long conns_pending; + /* connections that are waiting for first contact + * complete + */ + u8 peer_systemid[SMC_SYSTEMID_LEN]; + u8 peer_mac[ETH_ALEN]; /* = gid[8:10||13:15] */ + u8 peer_gid[SMC_GID_SIZE]; /* gid of peer*/ + int clcqpn; + int role; +}; + enum smc_lgr_role { /* possible roles of a link group */ SMC_CLNT, /* client */ SMC_SERV /* server */ }; +struct smc_lnk_cluster_compare_arg /* key for smc_lnk_cluster */ +{ + int smcr_version; + enum smc_lgr_role role; + u8 *peer_systemid; + u8 *peer_gid; + u8 *peer_mac; + int clcqpn; +}; + enum smc_link_state { /* possible states of a link */ SMC_LNK_UNUSED, /* link is unused */ SMC_LNK_INACTIVE, /* link is inactive */ SMC_LNK_ACTIVATING, /* link is being activated */ SMC_LNK_ACTIVE, /* link is active */ + SMC_LNK_TEAR_DWON, /* link is tear down */ }; +#define SMC_LNK_STATE_BIT(state) (1 << (state)) + +#define SMC_LNK_STATE_RECORD(lnk, state) \ + ((lnk)->state_record |= SMC_LNK_STATE_BIT(state)) + #define SMC_WR_BUF_SIZE 48 /* size of work request buffer */ #define SMC_WR_BUF_V2_SIZE 8192 /* size of v2 work request buffer */ @@ -145,6 +190,7 @@ struct smc_link { int ndev_ifidx; /* network device ifindex */ enum smc_link_state state; /* state of link */ + int state_record; /* record of previous state */ struct delayed_work llc_testlink_wrk; /* testlink worker */ struct completion llc_testlink_resp; /* wait for rx of testlink */ int llc_testlink_time; /* testlink interval */ @@ -557,6 +603,8 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb); int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb); +void smcr_lnk_cluster_on_lnk_state(struct smc_link *lnk); + static inline struct smc_link_group *smc_get_lgr(struct smc_link *link) { return link->lgr; diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 175026a..8134c15 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -1099,6 +1099,7 @@ int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry) goto out; out_clear_lnk: lnk_new->state = SMC_LNK_INACTIVE; + smcr_lnk_cluster_on_lnk_state(lnk_new); smcr_link_clear(lnk_new, false); out_reject: smc_llc_cli_add_link_reject(qentry); @@ -1278,6 +1279,7 @@ static void smc_llc_delete_asym_link(struct smc_link_group *lgr) return; /* no asymmetric link */ if (!smc_link_downing(&lnk_asym->state)) return; + smcr_lnk_cluster_on_lnk_state(lnk_asym); lnk_new = smc_switch_conns(lgr, lnk_asym, false); smc_wr_tx_wait_no_pending_sends(lnk_asym); if (!lnk_new) @@ -1492,6 +1494,7 @@ int smc_llc_srv_add_link(struct smc_link *link, out_err: if (link_new) { link_new->state = SMC_LNK_INACTIVE; + smcr_lnk_cluster_on_lnk_state(link_new); smcr_link_clear(link_new, false); } out: @@ -1602,8 +1605,10 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr) del_llc->reason = 0; smc_llc_send_message(lnk, &qentry->msg); /* response */ - if (smc_link_downing(&lnk_del->state)) + if (smc_link_downing(&lnk_del->state)) { + smcr_lnk_cluster_on_lnk_state(lnk); smc_switch_conns(lgr, lnk_del, false); + } smcr_link_clear(lnk_del, true); active_links = smc_llc_active_link_count(lgr); @@ -1676,6 +1681,7 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr) goto out; /* asymmetric link already deleted */ if (smc_link_downing(&lnk_del->state)) { + smcr_lnk_cluster_on_lnk_state(lnk); if (smc_switch_conns(lgr, lnk_del, false)) smc_wr_tx_wait_no_pending_sends(lnk_del); } @@ -2167,6 +2173,7 @@ void smc_llc_link_active(struct smc_link *link) schedule_delayed_work(&link->llc_testlink_wrk, link->llc_testlink_time); } + smcr_lnk_cluster_on_lnk_state(link); } /* called in worker context */ From patchwork Wed Aug 10 17:47:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940856 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0F7AC25B0E for ; Wed, 10 Aug 2022 17:47:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230095AbiHJRrs (ORCPT ); Wed, 10 Aug 2022 13:47:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231707AbiHJRrs (ORCPT ); Wed, 10 Aug 2022 13:47:48 -0400 Received: from out30-43.freemail.mail.aliyun.com (out30-43.freemail.mail.aliyun.com [115.124.30.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8DD386C17; Wed, 10 Aug 2022 10:47:46 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvtrmG_1660153663; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvtrmG_1660153663) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:44 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 02/10] net/smc: fix SMC_CLC_DECL_ERR_REGRMB without smc_server_lgr_pending Date: Thu, 11 Aug 2022 01:47:33 +0800 Message-Id: <01105a98ac715b6df6d019c0b6a9916814fdcff4.1660152975.git.alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" As commit "net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server" mentioned, it works only when all connection creations are completely protected by smc_server_lgr_pending lock, since we already cancel the lock, we need to re-fix the issues. Fixes: 4940a1fdf31c ("net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server") Signed-off-by: D. Wythe --- net/smc/af_smc.c | 2 ++ net/smc/smc_core.c | 11 ++++++++--- net/smc/smc_core.h | 21 +++++++++++++++++++++ 3 files changed, 31 insertions(+), 3 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index af4b0aa..c0842a9 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2413,6 +2413,7 @@ static void smc_listen_work(struct work_struct *work) if (rc) goto out_unlock; } + smc_conn_leave_rtoken_pending(new_smc, ini); smc_conn_save_peer_info(new_smc, cclc); smc_listen_out_connected(new_smc); SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini); @@ -2422,6 +2423,7 @@ static void smc_listen_work(struct work_struct *work) if (ini->is_smcd) mutex_unlock(&smc_server_lgr_pending); out_decl: + smc_conn_leave_rtoken_pending(new_smc, ini); smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0, proposal_version); out_free: diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index a3338cc..61a3854 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -2190,14 +2190,19 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) lgr->vlan_id == ini->vlan_id) && (role == SMC_CLNT || ini->is_smcd || (lgr->conns_num < SMC_RMBS_PER_LGR_MAX && - !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) { + (SMC_RMBS_PER_LGR_MAX - + bitmap_weight(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) + > atomic_read(&lgr->rtoken_pendings))))) { /* link group found */ ini->first_contact_local = 0; conn->lgr = lgr; rc = smc_lgr_register_conn(conn, false); write_unlock_bh(&lgr->conns_lock); - if (!rc && delayed_work_pending(&lgr->free_work)) - cancel_delayed_work(&lgr->free_work); + if (!rc) { + smc_conn_enter_rtoken_pending(smc, ini); + if (delayed_work_pending(&lgr->free_work)) + cancel_delayed_work(&lgr->free_work); + } break; } write_unlock_bh(&lgr->conns_lock); diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 199f533..acc2869 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -293,6 +293,9 @@ struct smc_link_group { struct rb_root conns_all; /* connection tree */ rwlock_t conns_lock; /* protects conns_all */ unsigned int conns_num; /* current # of connections */ + atomic_t rtoken_pendings;/* number of connection that + * lgr assigned but no rtoken got yet + */ unsigned short vlan_id; /* vlan id of link group */ struct list_head sndbufs[SMC_RMBE_SIZES];/* tx buffers */ @@ -603,6 +606,24 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb); int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb); +static inline void smc_conn_enter_rtoken_pending(struct smc_sock *smc, struct smc_init_info *ini) +{ + struct smc_link_group *lgr; + + lgr = smc->conn.lgr; + if (lgr && !ini->first_contact_local) + atomic_inc(&lgr->rtoken_pendings); +} + +static inline void smc_conn_leave_rtoken_pending(struct smc_sock *smc, struct smc_init_info *ini) +{ + struct smc_link_group *lgr; + + lgr = smc->conn.lgr; + if (lgr && !ini->first_contact_local) + atomic_dec(&lgr->rtoken_pendings); +} + void smcr_lnk_cluster_on_lnk_state(struct smc_link *lnk); static inline struct smc_link_group *smc_get_lgr(struct smc_link *link) From patchwork Wed Aug 10 17:47:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940858 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F3B3C28B2C for ; Wed, 10 Aug 2022 17:47:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232370AbiHJRru (ORCPT ); Wed, 10 Aug 2022 13:47:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232306AbiHJRrt (ORCPT ); Wed, 10 Aug 2022 13:47:49 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79AD086C24; Wed, 10 Aug 2022 10:47:47 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvtrmQ_1660153664; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvtrmQ_1660153664) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:44 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 03/10] net/smc: allow confirm/delete rkey response deliver multiplex Date: Thu, 11 Aug 2022 01:47:34 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" We know that all flows except confirm_rkey and delete_rkey are exclusive, confirm/delete rkey flows can run concurrently (local and remote). Although the protocol allows, all flows are actually mutually exclusive in implementation, dues to waiting for LLC messages is in serial. This aggravates the time for establishing or destroying a SMC-R connections, connections have to be queued in smc_llc_wait. We use rtokens or rkey to correlate a confirm/delete rkey message with its response. Before sending a message, we put context with rtokens or rkey into wait queue. When a response message received, we wakeup the context which with the same rtokens or rkey against the response message. Signed-off-by: D. Wythe --- net/smc/smc_llc.c | 174 +++++++++++++++++++++++++++++++++++++++++------------- net/smc/smc_wr.c | 10 ---- net/smc/smc_wr.h | 10 ++++ 3 files changed, 143 insertions(+), 51 deletions(-) diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 8134c15..b026df2 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -200,6 +200,7 @@ struct smc_llc_msg_delete_rkey_v2 { /* type 0x29 */ struct smc_llc_qentry { struct list_head list; struct smc_link *link; + void *private; union smc_llc_msg msg; }; @@ -479,19 +480,17 @@ int smc_llc_send_confirm_link(struct smc_link *link, return rc; } -/* send LLC confirm rkey request */ -static int smc_llc_send_confirm_rkey(struct smc_link *send_link, - struct smc_buf_desc *rmb_desc) +/* build LLC confirm rkey request */ +static int smc_llc_build_confirm_rkey_request(struct smc_link *send_link, + struct smc_buf_desc *rmb_desc, + struct smc_wr_tx_pend_priv **priv) { struct smc_llc_msg_confirm_rkey *rkeyllc; - struct smc_wr_tx_pend_priv *pend; struct smc_wr_buf *wr_buf; struct smc_link *link; int i, rc, rtok_ix; - if (!smc_wr_tx_link_hold(send_link)) - return -ENOLINK; - rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend); + rc = smc_llc_add_pending_send(send_link, &wr_buf, priv); if (rc) goto put_out; rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf; @@ -521,25 +520,20 @@ static int smc_llc_send_confirm_rkey(struct smc_link *send_link, cpu_to_be64((uintptr_t)rmb_desc->cpu_addr) : cpu_to_be64((u64)sg_dma_address (rmb_desc->sgt[send_link->link_idx].sgl)); - /* send llc message */ - rc = smc_wr_tx_send(send_link, pend); put_out: - smc_wr_tx_link_put(send_link); return rc; } -/* send LLC delete rkey request */ -static int smc_llc_send_delete_rkey(struct smc_link *link, - struct smc_buf_desc *rmb_desc) +/* build LLC delete rkey request */ +static int smc_llc_build_delete_rkey_request(struct smc_link *link, + struct smc_buf_desc *rmb_desc, + struct smc_wr_tx_pend_priv **priv) { struct smc_llc_msg_delete_rkey *rkeyllc; - struct smc_wr_tx_pend_priv *pend; struct smc_wr_buf *wr_buf; int rc; - if (!smc_wr_tx_link_hold(link)) - return -ENOLINK; - rc = smc_llc_add_pending_send(link, &wr_buf, &pend); + rc = smc_llc_add_pending_send(link, &wr_buf, priv); if (rc) goto put_out; rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf; @@ -548,10 +542,7 @@ static int smc_llc_send_delete_rkey(struct smc_link *link, smc_llc_init_msg_hdr(&rkeyllc->hd, link->lgr, sizeof(*rkeyllc)); rkeyllc->num_rkeys = 1; rkeyllc->rkey[0] = htonl(rmb_desc->mr[link->link_idx]->rkey); - /* send llc message */ - rc = smc_wr_tx_send(link, pend); put_out: - smc_wr_tx_link_put(link); return rc; } @@ -2023,7 +2014,8 @@ static void smc_llc_rx_response(struct smc_link *link, case SMC_LLC_DELETE_RKEY: if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry) break; /* drop out-of-flow response */ - goto assign; + __wake_up(&link->lgr->llc_msg_waiter, TASK_NORMAL, 1, qentry); + goto free; case SMC_LLC_CONFIRM_RKEY_CONT: /* not used because max links is 3 */ break; @@ -2032,6 +2024,7 @@ static void smc_llc_rx_response(struct smc_link *link, qentry->msg.raw.hdr.common.type); break; } +free: kfree(qentry); return; assign: @@ -2191,25 +2184,98 @@ void smc_llc_link_clear(struct smc_link *link, bool log) cancel_delayed_work_sync(&link->llc_testlink_wrk); } +static int smc_llc_rkey_response_wake_function(struct wait_queue_entry *wq_entry, + unsigned int mode, int sync, void *key) +{ + struct smc_llc_qentry *except, *incoming; + u8 except_llc_type; + + /* not a rkey response */ + if (!key) + return 0; + + except = wq_entry->private; + incoming = key; + + except_llc_type = except->msg.raw.hdr.common.llc_type; + + /* except LLC MSG TYPE mismatch */ + if (except_llc_type != incoming->msg.raw.hdr.common.llc_type) + return 0; + + switch (except_llc_type) { + case SMC_LLC_CONFIRM_RKEY: + if (memcmp(except->msg.confirm_rkey.rtoken, incoming->msg.confirm_rkey.rtoken, + sizeof(struct smc_rmb_rtoken) * + except->msg.confirm_rkey.rtoken[0].num_rkeys)) + return 0; + break; + case SMC_LLC_DELETE_RKEY: + if (memcmp(except->msg.delete_rkey.rkey, incoming->msg.delete_rkey.rkey, + sizeof(__be32) * except->msg.delete_rkey.num_rkeys)) + return 0; + break; + default: + panic("invalid except llc msg %d", except_llc_type); + return 0; + } + + /* match, save hdr */ + memcpy(&except->msg.raw.hdr, &incoming->msg.raw.hdr, sizeof(except->msg.raw.hdr)); + + wq_entry->private = except->private; + return woken_wake_function(wq_entry, mode, sync, NULL); +} + /* register a new rtoken at the remote peer (for all links) */ int smc_llc_do_confirm_rkey(struct smc_link *send_link, struct smc_buf_desc *rmb_desc) { + long timeout = SMC_LLC_WAIT_TIME; struct smc_link_group *lgr = send_link->lgr; - struct smc_llc_qentry *qentry = NULL; - int rc = 0; + struct smc_llc_qentry qentry; + struct smc_wr_tx_pend *pend; + struct smc_wr_tx_pend_priv *priv; + DEFINE_WAIT_FUNC(wait, smc_llc_rkey_response_wake_function); + int rc = 0, flags; - rc = smc_llc_send_confirm_rkey(send_link, rmb_desc); + if (!smc_wr_tx_link_hold(send_link)) + return -ENOLINK; + + rc = smc_llc_build_confirm_rkey_request(send_link, rmb_desc, &priv); if (rc) goto out; - /* receive CONFIRM RKEY response from server over RoCE fabric */ - qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME, - SMC_LLC_CONFIRM_RKEY); - if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG)) + + pend = container_of(priv, struct smc_wr_tx_pend, priv); + /* make a copy of send msg */ + memcpy(&qentry.msg.confirm_rkey, send_link->wr_tx_bufs[pend->idx].raw, + sizeof(qentry.msg.confirm_rkey)); + + qentry.private = wait.private; + wait.private = &qentry; + + add_wait_queue(&lgr->llc_msg_waiter, &wait); + + /* send llc message */ + rc = smc_wr_tx_send(send_link, priv); + smc_wr_tx_link_put(send_link); + if (rc) { + remove_wait_queue(&lgr->llc_msg_waiter, &wait); + goto out; + } + + while (!signal_pending(current) && timeout) { + timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); + if (qentry.msg.raw.hdr.flags & SMC_LLC_FLAG_RESP) + break; + } + + remove_wait_queue(&lgr->llc_msg_waiter, &wait); + flags = qentry.msg.raw.hdr.flags; + + if (!(flags & SMC_LLC_FLAG_RESP) || flags & SMC_LLC_FLAG_RKEY_NEG) rc = -EFAULT; out: - if (qentry) - smc_llc_flow_qentry_del(&lgr->llc_flow_lcl); return rc; } @@ -2217,26 +2283,52 @@ int smc_llc_do_confirm_rkey(struct smc_link *send_link, int smc_llc_do_delete_rkey(struct smc_link_group *lgr, struct smc_buf_desc *rmb_desc) { - struct smc_llc_qentry *qentry = NULL; + long timeout = SMC_LLC_WAIT_TIME; + struct smc_llc_qentry qentry; + struct smc_wr_tx_pend *pend; struct smc_link *send_link; - int rc = 0; + struct smc_wr_tx_pend_priv *priv; + DEFINE_WAIT_FUNC(wait, smc_llc_rkey_response_wake_function); + int rc = 0, flags; send_link = smc_llc_usable_link(lgr); - if (!send_link) + if (!send_link || !smc_wr_tx_link_hold(send_link)) return -ENOLINK; - /* protected by llc_flow control */ - rc = smc_llc_send_delete_rkey(send_link, rmb_desc); + rc = smc_llc_build_delete_rkey_request(send_link, rmb_desc, &priv); if (rc) goto out; - /* receive DELETE RKEY response from server over RoCE fabric */ - qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME, - SMC_LLC_DELETE_RKEY); - if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG)) + + pend = container_of(priv, struct smc_wr_tx_pend, priv); + /* make a copy of send msg */ + memcpy(&qentry.msg.delete_link, send_link->wr_tx_bufs[pend->idx].raw, + sizeof(qentry.msg.delete_link)); + + qentry.private = wait.private; + wait.private = &qentry; + + add_wait_queue(&lgr->llc_msg_waiter, &wait); + + /* send llc message */ + rc = smc_wr_tx_send(send_link, priv); + smc_wr_tx_link_put(send_link); + if (rc) { + remove_wait_queue(&lgr->llc_msg_waiter, &wait); + goto out; + } + + while (!signal_pending(current) && timeout) { + timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); + if (qentry.msg.raw.hdr.flags & SMC_LLC_FLAG_RESP) + break; + } + + remove_wait_queue(&lgr->llc_msg_waiter, &wait); + flags = qentry.msg.raw.hdr.flags; + + if (!(flags & SMC_LLC_FLAG_RESP) || flags & SMC_LLC_FLAG_RKEY_NEG) rc = -EFAULT; out: - if (qentry) - smc_llc_flow_qentry_del(&lgr->llc_flow_lcl); return rc; } diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c index 26f8f24..52af94f 100644 --- a/net/smc/smc_wr.c +++ b/net/smc/smc_wr.c @@ -37,16 +37,6 @@ static DEFINE_HASHTABLE(smc_wr_rx_hash, SMC_WR_RX_HASH_BITS); static DEFINE_SPINLOCK(smc_wr_rx_hash_lock); -struct smc_wr_tx_pend { /* control data for a pending send request */ - u64 wr_id; /* work request id sent */ - smc_wr_tx_handler handler; - enum ib_wc_status wc_status; /* CQE status */ - struct smc_link *link; - u32 idx; - struct smc_wr_tx_pend_priv priv; - u8 compl_requested; -}; - /******************************** send queue *********************************/ /*------------------------------- completion --------------------------------*/ diff --git a/net/smc/smc_wr.h b/net/smc/smc_wr.h index a54e90a..9946ed5 100644 --- a/net/smc/smc_wr.h +++ b/net/smc/smc_wr.h @@ -46,6 +46,16 @@ struct smc_wr_rx_handler { u8 type; }; +struct smc_wr_tx_pend { /* control data for a pending send request */ + u64 wr_id; /* work request id sent */ + smc_wr_tx_handler handler; + enum ib_wc_status wc_status; /* CQE status */ + struct smc_link *link; + u32 idx; + struct smc_wr_tx_pend_priv priv; + u8 compl_requested; +}; + /* Only used by RDMA write WRs. * All other WRs (CDC/LLC) use smc_wr_tx_send handling WR_ID implicitly */ From patchwork Wed Aug 10 17:47:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940859 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75D40C25B07 for ; Wed, 10 Aug 2022 17:48:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232593AbiHJRsB (ORCPT ); Wed, 10 Aug 2022 13:48:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232408AbiHJRrv (ORCPT ); Wed, 10 Aug 2022 13:47:51 -0400 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5074A86C06; Wed, 10 Aug 2022 10:47:49 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045176;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvokRq_1660153665; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvokRq_1660153665) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:45 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 04/10] net/smc: make SMC_LLC_FLOW_RKEY run concurrently Date: Thu, 11 Aug 2022 01:47:35 +0800 Message-Id: <9191753eb6f3726e0ed56c7fec6c7d55893e2c76.1660152975.git.alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" Once confirm/delete rkey response can be multiplex delivered, We can allow parallel execution of start (remote) or initialization (local) a SMC_LLC_FLOW_RKEY flow. This patch will count the flows executed in parallel, and only when the count reaches zero will the current flow type be removed. Signed-off-by: D. Wythe --- net/smc/smc_core.h | 1 + net/smc/smc_llc.c | 69 +++++++++++++++++++++++++++++++++++++++++------------- net/smc/smc_llc.h | 6 +++++ 3 files changed, 60 insertions(+), 16 deletions(-) diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index acc2869..8490676 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -286,6 +286,7 @@ enum smc_llc_flowtype { struct smc_llc_flow { enum smc_llc_flowtype type; struct smc_llc_qentry *qentry; + refcount_t parallel_refcnt; }; struct smc_link_group { diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index b026df2..965a3cc 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -231,10 +231,18 @@ static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow, flow->qentry = qentry; } -static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type, +static void smc_llc_flow_parallel(struct smc_link_group *lgr, struct smc_llc_flow *flow, struct smc_llc_qentry *qentry) { u8 msg_type = qentry->msg.raw.hdr.common.llc_type; + u8 flow_type = flow->type; + + /* SMC_LLC_FLOW_RKEY can be parallel */ + if (flow_type == SMC_LLC_FLOW_RKEY && + (msg_type == SMC_LLC_CONFIRM_RKEY || msg_type == SMC_LLC_DELETE_RKEY)) { + refcount_inc(&flow->parallel_refcnt); + return; + } if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) && flow_type != msg_type && !lgr->delayed_event) { @@ -261,7 +269,7 @@ static bool smc_llc_flow_start(struct smc_llc_flow *flow, spin_lock_bh(&lgr->llc_flow_lock); if (flow->type) { /* a flow is already active */ - smc_llc_flow_parallel(lgr, flow->type, qentry); + smc_llc_flow_parallel(lgr, flow, qentry); spin_unlock_bh(&lgr->llc_flow_lock); return false; } @@ -280,6 +288,7 @@ static bool smc_llc_flow_start(struct smc_llc_flow *flow, flow->type = SMC_LLC_FLOW_NONE; } smc_llc_flow_qentry_set(flow, qentry); + refcount_set(&flow->parallel_refcnt, 1); spin_unlock_bh(&lgr->llc_flow_lock); return true; } @@ -289,6 +298,7 @@ int smc_llc_flow_initiate(struct smc_link_group *lgr, enum smc_llc_flowtype type) { enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE; + bool accept = false; int rc; /* all flows except confirm_rkey and delete_rkey are exclusive, @@ -300,10 +310,39 @@ int smc_llc_flow_initiate(struct smc_link_group *lgr, if (list_empty(&lgr->list)) return -ENODEV; spin_lock_bh(&lgr->llc_flow_lock); - if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE && - (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE || - lgr->llc_flow_rmt.type == allowed_remote)) { - lgr->llc_flow_lcl.type = type; + + /* Flow is initialized only if the following conditions are met: + * incoming flow local flow remote flow + * exclusive NONE NONE + * SMC_LLC_FLOW_RKEY SMC_LLC_FLOW_RKEY SMC_LLC_FLOW_RKEY + * SMC_LLC_FLOW_RKEY NONE SMC_LLC_FLOW_RKEY + * SMC_LLC_FLOW_RKEY SMC_LLC_FLOW_RKEY NONE + */ + switch (type) { + case SMC_LLC_FLOW_RKEY: + if (!SMC_IS_PARALLEL_FLOW(lgr->llc_flow_lcl.type)) + break; + if (!SMC_IS_PARALLEL_FLOW(lgr->llc_flow_rmt.type)) + break; + /* accepted */ + accept = true; + break; + default: + if (!SMC_IS_NONE_FLOW(lgr->llc_flow_lcl.type)) + break; + if (!SMC_IS_NONE_FLOW(lgr->llc_flow_rmt.type)) + break; + /* accepted */ + accept = true; + break; + } + if (accept) { + if (SMC_IS_NONE_FLOW(lgr->llc_flow_lcl.type)) { + lgr->llc_flow_lcl.type = type; + refcount_set(&lgr->llc_flow_lcl.parallel_refcnt, 1); + } else { + refcount_inc(&lgr->llc_flow_lcl.parallel_refcnt); + } spin_unlock_bh(&lgr->llc_flow_lock); return 0; } @@ -322,6 +361,10 @@ int smc_llc_flow_initiate(struct smc_link_group *lgr, void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow) { spin_lock_bh(&lgr->llc_flow_lock); + if (!refcount_dec_and_test(&flow->parallel_refcnt)) { + spin_unlock_bh(&lgr->llc_flow_lock); + return; + } memset(flow, 0, sizeof(*flow)); flow->type = SMC_LLC_FLOW_NONE; spin_unlock_bh(&lgr->llc_flow_lock); @@ -1729,16 +1772,14 @@ static void smc_llc_delete_link_work(struct work_struct *work) } /* process a confirm_rkey request from peer, remote flow */ -static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr) +static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr, struct smc_llc_qentry *qentry) { struct smc_llc_msg_confirm_rkey *llc; - struct smc_llc_qentry *qentry; struct smc_link *link; int num_entries; int rk_idx; int i; - qentry = lgr->llc_flow_rmt.qentry; llc = &qentry->msg.confirm_rkey; link = qentry->link; @@ -1765,19 +1806,16 @@ static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr) llc->hd.flags |= SMC_LLC_FLAG_RESP; smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc)); smc_llc_send_message(link, &qentry->msg); - smc_llc_flow_qentry_del(&lgr->llc_flow_rmt); } /* process a delete_rkey request from peer, remote flow */ -static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr) +static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr, struct smc_llc_qentry *qentry) { struct smc_llc_msg_delete_rkey *llc; - struct smc_llc_qentry *qentry; struct smc_link *link; u8 err_mask = 0; int i, max; - qentry = lgr->llc_flow_rmt.qentry; llc = &qentry->msg.delete_rkey; link = qentry->link; @@ -1815,7 +1853,6 @@ static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr) finish: llc->hd.flags |= SMC_LLC_FLAG_RESP; smc_llc_send_message(link, &qentry->msg); - smc_llc_flow_qentry_del(&lgr->llc_flow_rmt); } static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type) @@ -1916,7 +1953,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry) /* new request from remote, assign to remote flow */ if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) { /* process here, does not wait for more llc msgs */ - smc_llc_rmt_conf_rkey(lgr); + smc_llc_rmt_conf_rkey(lgr, qentry); smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt); } return; @@ -1929,7 +1966,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry) /* new request from remote, assign to remote flow */ if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) { /* process here, does not wait for more llc msgs */ - smc_llc_rmt_delete_rkey(lgr); + smc_llc_rmt_delete_rkey(lgr, qentry); smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt); } return; diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h index 4404e52..005a81e 100644 --- a/net/smc/smc_llc.h +++ b/net/smc/smc_llc.h @@ -48,6 +48,12 @@ enum smc_llc_msg_type { #define smc_link_downing(state) \ (cmpxchg(state, SMC_LNK_ACTIVE, SMC_LNK_INACTIVE) == SMC_LNK_ACTIVE) +#define SMC_IS_NONE_FLOW(type) \ + ((type) == SMC_LLC_FLOW_NONE) + +#define SMC_IS_PARALLEL_FLOW(type) \ + (((type) == SMC_LLC_FLOW_RKEY) || SMC_IS_NONE_FLOW(type)) + /* LLC DELETE LINK Request Reason Codes */ #define SMC_LLC_DEL_LOST_PATH 0x00010000 #define SMC_LLC_DEL_OP_INIT_TERM 0x00020000 From patchwork Wed Aug 10 17:47:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940862 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF947C25B0C for ; Wed, 10 Aug 2022 17:48:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232842AbiHJRsD (ORCPT ); Wed, 10 Aug 2022 13:48:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232482AbiHJRsB (ORCPT ); Wed, 10 Aug 2022 13:48:01 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F07C8C012; Wed, 10 Aug 2022 10:47:50 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvs-tS_1660153666; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvs-tS_1660153666) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:46 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 05/10] net/smc: llc_conf_mutex refactor, replace it with rw_semaphore Date: Thu, 11 Aug 2022 01:47:36 +0800 Message-Id: <7a58a89a310d9760f183a5db60844e439a613a4a.1660152975.git.alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" llc_conf_mutex was used to protect links and link related configurations in the same link group, for example, add or delete links. However, in most cases, the protected critical area has only read semantics and with no write semantics at all, such as obtaining a usable link or an available rmb_desc. This patch do simply code refactoring, replace mutex with rw_semaphore, replace mutex_lock with down_write and replace mutex_unlock with up_write. Theoretically, this replacement is equivalent, but after this patch, we can distinguish lock granularity according to different semantics of critical areas. Signed-off-by: D. Wythe --- net/smc/af_smc.c | 8 ++++---- net/smc/smc_core.c | 20 ++++++++++---------- net/smc/smc_core.h | 2 +- net/smc/smc_llc.c | 18 +++++++++--------- 4 files changed, 24 insertions(+), 24 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index c0842a9..51b90e2 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -498,7 +498,7 @@ static int smcr_lgr_reg_sndbufs(struct smc_link *link, return -EINVAL; /* protect against parallel smcr_link_reg_buf() */ - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { if (!smc_link_active(&lgr->lnk[i])) continue; @@ -506,7 +506,7 @@ static int smcr_lgr_reg_sndbufs(struct smc_link *link, if (rc) break; } - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); return rc; } @@ -523,7 +523,7 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, /* protect against parallel smc_llc_cli_rkey_exchange() and * parallel smcr_link_reg_buf() */ - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { if (!smc_link_active(&lgr->lnk[i])) continue; @@ -540,7 +540,7 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, } rmb_desc->is_conf_rkey = true; out: - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl); return rc; } diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 61a3854..fc8deec 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1388,10 +1388,10 @@ static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb, rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY); if (!rc) { /* protect against smc_llc_cli_rkey_exchange() */ - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); smc_llc_do_delete_rkey(lgr, buf_desc); buf_desc->is_conf_rkey = false; - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl); } } @@ -1661,12 +1661,12 @@ static void smc_lgr_free(struct smc_link_group *lgr) int i; if (!lgr->is_smcd) { - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { if (lgr->lnk[i].state != SMC_LNK_UNUSED) smcr_link_clear(&lgr->lnk[i], false); } - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); smc_llc_lgr_clear(lgr); } @@ -1980,12 +1980,12 @@ static void smcr_link_down(struct smc_link *lnk) } else { if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) { /* another llc task is ongoing */ - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) || lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE), SMC_LLC_WAIT_TIME); - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); } if (!list_empty(&lgr->list)) { smc_llc_send_delete_link(to_lnk, del_link_id, @@ -2047,9 +2047,9 @@ static void smc_link_down_work(struct work_struct *work) if (list_empty(&lgr->list)) return; wake_up_all(&lgr->llc_msg_waiter); - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); smcr_link_down(link); - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); } static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev, @@ -2581,7 +2581,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, int i, rc = 0; /* protect against parallel link reconfiguration */ - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { struct smc_link *lnk = &lgr->lnk[i]; @@ -2593,7 +2593,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, } } out: - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); return rc; } diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 8490676..559d330 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -346,7 +346,7 @@ struct smc_link_group { /* queue for llc events */ spinlock_t llc_event_q_lock; /* protects llc_event_q */ - struct mutex llc_conf_mutex; + struct rw_semaphore llc_conf_mutex; /* protects lgr reconfig. */ struct work_struct llc_add_link_work; struct work_struct llc_del_link_work; diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 965a3cc..d744937 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -1237,12 +1237,12 @@ static void smc_llc_process_cli_add_link(struct smc_link_group *lgr) qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl); - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); if (smc_llc_is_local_add_link(&qentry->msg)) smc_llc_cli_add_link_invite(qentry->link, qentry); else smc_llc_cli_add_link(qentry->link, qentry); - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); } static int smc_llc_active_link_count(struct smc_link_group *lgr) @@ -1546,13 +1546,13 @@ static void smc_llc_process_srv_add_link(struct smc_link_group *lgr) qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl); - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); rc = smc_llc_srv_add_link(link, qentry); if (!rc && lgr->type == SMC_LGR_SYMMETRIC) { /* delete any asymmetric link */ smc_llc_delete_asym_link(lgr); } - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); kfree(qentry); } @@ -1619,7 +1619,7 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr) smc_lgr_terminate_sched(lgr); goto out; } - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); /* delete single link */ for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) { if (lgr->lnk[lnk_idx].link_id != del_llc->link_num) @@ -1655,7 +1655,7 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr) smc_lgr_terminate_sched(lgr); } out_unlock: - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); out: kfree(qentry); } @@ -1691,7 +1691,7 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr) int active_links; int i; - mutex_lock(&lgr->llc_conf_mutex); + down_write(&lgr->llc_conf_mutex); qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl); lnk = qentry->link; del_llc = &qentry->msg.delete_link; @@ -1748,7 +1748,7 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr) smc_llc_add_link_local(lnk); } out: - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); kfree(qentry); } @@ -2162,7 +2162,7 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc) spin_lock_init(&lgr->llc_flow_lock); init_waitqueue_head(&lgr->llc_flow_waiter); init_waitqueue_head(&lgr->llc_msg_waiter); - mutex_init(&lgr->llc_conf_mutex); + init_rwsem(&lgr->llc_conf_mutex); lgr->llc_testlink_time = READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); } From patchwork Wed Aug 10 17:47:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940861 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0984C282E7 for ; Wed, 10 Aug 2022 17:48:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232943AbiHJRsE (ORCPT ); Wed, 10 Aug 2022 13:48:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232500AbiHJRsB (ORCPT ); Wed, 10 Aug 2022 13:48:01 -0400 Received: from out199-14.us.a.mail.aliyun.com (out199-14.us.a.mail.aliyun.com [47.90.199.14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 786718C01B; Wed, 10 Aug 2022 10:47:51 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R751e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046050;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvpTf-_1660153667; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvpTf-_1660153667) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:47 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 06/10] net/smc: use read semaphores to reduce unnecessary blocking in smc_buf_create() & smcr_buf_unuse() Date: Thu, 11 Aug 2022 01:47:37 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" Following is part of Off-CPU graph during frequent SMC-R short-lived processing: process_one_work (51.19%) smc_close_passive_work (28.36%) smcr_buf_unuse (28.34%) rwsem_down_write_slowpath (28.22%) smc_listen_work (22.83%) smc_clc_wait_msg (1.84%) smc_buf_create (20.45%) smcr_buf_map_usable_links rwsem_down_write_slowpath (20.43%) smcr_lgr_reg_rmbs (0.53%) rwsem_down_write_slowpath (0.43%) smc_llc_do_confirm_rkey (0.08%) We can clearly see that during the connection establishment time, waiting time of connections is not on IO, but on llc_conf_mutex. What is more important, the core critical area (smcr_buf_unuse() & smc_buf_create()) only perfroms read semantics on links, we can easily replace it with read semaphore. Signed-off-by: D. Wythe --- net/smc/smc_core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index fc8deec..113804d 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1388,10 +1388,10 @@ static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb, rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY); if (!rc) { /* protect against smc_llc_cli_rkey_exchange() */ - down_write(&lgr->llc_conf_mutex); + down_read(&lgr->llc_conf_mutex); smc_llc_do_delete_rkey(lgr, buf_desc); buf_desc->is_conf_rkey = false; - up_write(&lgr->llc_conf_mutex); + up_read(&lgr->llc_conf_mutex); smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl); } } @@ -2581,7 +2581,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, int i, rc = 0; /* protect against parallel link reconfiguration */ - down_write(&lgr->llc_conf_mutex); + down_read(&lgr->llc_conf_mutex); for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { struct smc_link *lnk = &lgr->lnk[i]; @@ -2593,7 +2593,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, } } out: - up_write(&lgr->llc_conf_mutex); + up_read(&lgr->llc_conf_mutex); return rc; } From patchwork Wed Aug 10 17:47:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940860 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5EA1C25B0D for ; Wed, 10 Aug 2022 17:48:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232799AbiHJRsC (ORCPT ); Wed, 10 Aug 2022 13:48:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232450AbiHJRrx (ORCPT ); Wed, 10 Aug 2022 13:47:53 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 789968C01C; Wed, 10 Aug 2022 10:47:51 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvtUGn_1660153668; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvtUGn_1660153668) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:48 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 07/10] net/smc: reduce unnecessary blocking in smcr_lgr_reg_rmbs() Date: Thu, 11 Aug 2022 01:47:38 +0800 Message-Id: <46f364ce7878b740e58bf44d3bed5fe23c64a260.1660152975.git.alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" Unlike smc_buf_create() and smcr_buf_unuse(), smcr_lgr_reg_rmbs() is exclusive when assigned rmb_desc was not registered, although it can be executed in parallel when assigned rmb_desc was registered already and only performs read semtamics on it. Hence, we can not simply replace it with read semaphore. The idea here is that if the assigned rmb_desc was registered already, use read semaphore to protect the critical section, once the assigned rmb_desc was not registered, keep using keep write semaphore still to keep its exclusivity. Thanks to the reusable features of rmb_desc, which allows us to execute in parallel in most cases. Signed-off-by: D. Wythe --- net/smc/af_smc.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 51b90e2..39dbf39 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -516,10 +516,25 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, { struct smc_link_group *lgr = link->lgr; int i, rc = 0; + bool slow = false; rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY); if (rc) return rc; + + down_read(&lgr->llc_conf_mutex); + for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { + if (!smc_link_active(&lgr->lnk[i])) + continue; + if (!rmb_desc->is_reg_mr[link->link_idx]) { + up_read(&lgr->llc_conf_mutex); + goto slow_path; + } + } + /* mr register already */ + goto fast_path; +slow_path: + slow = true; /* protect against parallel smc_llc_cli_rkey_exchange() and * parallel smcr_link_reg_buf() */ @@ -531,7 +546,7 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, if (rc) goto out; } - +fast_path: /* exchange confirm_rkey msg with peer */ rc = smc_llc_do_confirm_rkey(link, rmb_desc); if (rc) { @@ -540,7 +555,7 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, } rmb_desc->is_conf_rkey = true; out: - up_write(&lgr->llc_conf_mutex); + slow ? up_write(&lgr->llc_conf_mutex) : up_read(&lgr->llc_conf_mutex); smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl); return rc; } From patchwork Wed Aug 10 17:47:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940865 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF70DC25B07 for ; Wed, 10 Aug 2022 17:48:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233096AbiHJRs0 (ORCPT ); Wed, 10 Aug 2022 13:48:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232859AbiHJRsD (ORCPT ); Wed, 10 Aug 2022 13:48:03 -0400 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E1B58C01D; Wed, 10 Aug 2022 10:47:55 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R751e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvmsJ1_1660153669; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvmsJ1_1660153669) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:49 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 08/10] net/smc: replace mutex rmbs_lock and sndbufs_lock with rw_semaphore Date: Thu, 11 Aug 2022 01:47:39 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" It's clear that rmbs_lock and sndbufs_lock are aims to protect the rmbs list or the sndbufs list. During conenction establieshment, smc_buf_get_slot() will always be invoke, and it only performs read semantics in rmbs list and sndbufs list. Based on the above considerations, we replace mutex with rw_semaphore. Only smc_buf_get_slot() use down_read() to allow smc_buf_get_slot() run concurrently, other part use down_write() to keep exclusive semantics. Signed-off-by: D. Wythe --- net/smc/smc_core.c | 55 +++++++++++++++++++++++++++--------------------------- net/smc/smc_core.h | 4 ++-- net/smc/smc_llc.c | 16 ++++++++-------- 3 files changed, 38 insertions(+), 37 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 113804d..b90970a 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1138,8 +1138,8 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) lgr->freeing = 0; lgr->vlan_id = ini->vlan_id; refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */ - mutex_init(&lgr->sndbufs_lock); - mutex_init(&lgr->rmbs_lock); + init_rwsem(&lgr->sndbufs_lock); + init_rwsem(&lgr->rmbs_lock); rwlock_init(&lgr->conns_lock); for (i = 0; i < SMC_RMBE_SIZES; i++) { INIT_LIST_HEAD(&lgr->sndbufs[i]); @@ -1380,7 +1380,7 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb, struct smc_link_group *lgr) { - struct mutex *lock; /* lock buffer list */ + struct rw_semaphore *lock; /* lock buffer list */ int rc; if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) { @@ -1400,9 +1400,9 @@ static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb, /* buf registration failed, reuse not possible */ lock = is_rmb ? &lgr->rmbs_lock : &lgr->sndbufs_lock; - mutex_lock(lock); + down_write(lock); list_del(&buf_desc->list); - mutex_unlock(lock); + up_write(lock); smc_buf_free(lgr, is_rmb, buf_desc); } else { @@ -1506,15 +1506,16 @@ static void smcr_buf_unmap_lgr(struct smc_link *lnk) int i; for (i = 0; i < SMC_RMBE_SIZES; i++) { - mutex_lock(&lgr->rmbs_lock); + down_write(&lgr->rmbs_lock); list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) smcr_buf_unmap_link(buf_desc, true, lnk); - mutex_unlock(&lgr->rmbs_lock); - mutex_lock(&lgr->sndbufs_lock); + up_write(&lgr->rmbs_lock); + + down_write(&lgr->sndbufs_lock); list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) smcr_buf_unmap_link(buf_desc, false, lnk); - mutex_unlock(&lgr->sndbufs_lock); + up_write(&lgr->sndbufs_lock); } } @@ -2324,19 +2325,19 @@ int smc_uncompress_bufsize(u8 compressed) * buffer size; if not available, return NULL */ static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize, - struct mutex *lock, + struct rw_semaphore *lock, struct list_head *buf_list) { struct smc_buf_desc *buf_slot; - mutex_lock(lock); + down_read(lock); list_for_each_entry(buf_slot, buf_list, list) { if (cmpxchg(&buf_slot->used, 0, 1) == 0) { - mutex_unlock(lock); + up_read(lock); return buf_slot; } } - mutex_unlock(lock); + up_read(lock); return NULL; } @@ -2445,13 +2446,13 @@ int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc) return 0; } -static int _smcr_buf_map_lgr(struct smc_link *lnk, struct mutex *lock, +static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock, struct list_head *lst, bool is_rmb) { struct smc_buf_desc *buf_desc, *bf; int rc = 0; - mutex_lock(lock); + down_write(lock); list_for_each_entry_safe(buf_desc, bf, lst, list) { if (!buf_desc->used) continue; @@ -2460,7 +2461,7 @@ static int _smcr_buf_map_lgr(struct smc_link *lnk, struct mutex *lock, goto out; } out: - mutex_unlock(lock); + up_write(lock); return rc; } @@ -2493,37 +2494,37 @@ int smcr_buf_reg_lgr(struct smc_link *lnk) int i, rc = 0; /* reg all RMBs for a new link */ - mutex_lock(&lgr->rmbs_lock); + down_write(&lgr->rmbs_lock); for (i = 0; i < SMC_RMBE_SIZES; i++) { list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) { if (!buf_desc->used) continue; rc = smcr_link_reg_buf(lnk, buf_desc); if (rc) { - mutex_unlock(&lgr->rmbs_lock); + up_write(&lgr->rmbs_lock); return rc; } } } - mutex_unlock(&lgr->rmbs_lock); + up_write(&lgr->rmbs_lock); if (lgr->buf_type == SMCR_PHYS_CONT_BUFS) return rc; /* reg all vzalloced sndbufs for a new link */ - mutex_lock(&lgr->sndbufs_lock); + down_write(&lgr->sndbufs_lock); for (i = 0; i < SMC_RMBE_SIZES; i++) { list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) { if (!buf_desc->used || !buf_desc->is_vm) continue; rc = smcr_link_reg_buf(lnk, buf_desc); if (rc) { - mutex_unlock(&lgr->sndbufs_lock); + up_write(&lgr->sndbufs_lock); return rc; } } } - mutex_unlock(&lgr->sndbufs_lock); + up_write(&lgr->sndbufs_lock); return rc; } @@ -2641,7 +2642,7 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb) struct list_head *buf_list; int bufsize, bufsize_short; bool is_dgraded = false; - struct mutex *lock; /* lock buffer list */ + struct rw_semaphore *lock; /* lock buffer list */ int sk_buf_size; if (is_rmb) @@ -2689,9 +2690,9 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb) SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb); SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize); buf_desc->used = 1; - mutex_lock(lock); + down_write(lock); list_add(&buf_desc->list, buf_list); - mutex_unlock(lock); + up_write(lock); break; /* found */ } @@ -2765,9 +2766,9 @@ int smc_buf_create(struct smc_sock *smc, bool is_smcd) /* create rmb */ rc = __smc_buf_create(smc, is_smcd, true); if (rc) { - mutex_lock(&smc->conn.lgr->sndbufs_lock); + down_write(&smc->conn.lgr->sndbufs_lock); list_del(&smc->conn.sndbuf_desc->list); - mutex_unlock(&smc->conn.lgr->sndbufs_lock); + up_write(&smc->conn.lgr->sndbufs_lock); smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc); smc->conn.sndbuf_desc = NULL; } diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 559d330..008148c 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -300,9 +300,9 @@ struct smc_link_group { unsigned short vlan_id; /* vlan id of link group */ struct list_head sndbufs[SMC_RMBE_SIZES];/* tx buffers */ - struct mutex sndbufs_lock; /* protects tx buffers */ + struct rw_semaphore sndbufs_lock; /* protects tx buffers */ struct list_head rmbs[SMC_RMBE_SIZES]; /* rx buffers */ - struct mutex rmbs_lock; /* protects rx buffers */ + struct rw_semaphore rmbs_lock; /* protects rx buffers */ u8 id[SMC_LGR_ID_SIZE]; /* unique lgr id */ struct delayed_work free_work; /* delayed freeing of an lgr */ diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index d744937..76f9906 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -642,7 +642,7 @@ static int smc_llc_fill_ext_v2(struct smc_llc_msg_add_link_v2_ext *ext, prim_lnk_idx = link->link_idx; lnk_idx = link_new->link_idx; - mutex_lock(&lgr->rmbs_lock); + down_write(&lgr->rmbs_lock); ext->num_rkeys = lgr->conns_num; if (!ext->num_rkeys) goto out; @@ -662,7 +662,7 @@ static int smc_llc_fill_ext_v2(struct smc_llc_msg_add_link_v2_ext *ext, } len += i * sizeof(ext->rt[0]); out: - mutex_unlock(&lgr->rmbs_lock); + up_write(&lgr->rmbs_lock); return len; } @@ -923,7 +923,7 @@ static int smc_llc_cli_rkey_exchange(struct smc_link *link, int rc = 0; int i; - mutex_lock(&lgr->rmbs_lock); + down_write(&lgr->rmbs_lock); num_rkeys_send = lgr->conns_num; buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst); do { @@ -950,7 +950,7 @@ static int smc_llc_cli_rkey_exchange(struct smc_link *link, break; } while (num_rkeys_send || num_rkeys_recv); - mutex_unlock(&lgr->rmbs_lock); + up_write(&lgr->rmbs_lock); return rc; } @@ -1033,14 +1033,14 @@ static void smc_llc_save_add_link_rkeys(struct smc_link *link, ext = (struct smc_llc_msg_add_link_v2_ext *)((u8 *)lgr->wr_rx_buf_v2 + SMC_WR_TX_SIZE); max = min_t(u8, ext->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2); - mutex_lock(&lgr->rmbs_lock); + down_write(&lgr->rmbs_lock); for (i = 0; i < max; i++) { smc_rtoken_set(lgr, link->link_idx, link_new->link_idx, ext->rt[i].rmb_key, ext->rt[i].rmb_vaddr_new, ext->rt[i].rmb_key_new); } - mutex_unlock(&lgr->rmbs_lock); + up_write(&lgr->rmbs_lock); } static void smc_llc_save_add_link_info(struct smc_link *link, @@ -1349,7 +1349,7 @@ static int smc_llc_srv_rkey_exchange(struct smc_link *link, int rc = 0; int i; - mutex_lock(&lgr->rmbs_lock); + down_write(&lgr->rmbs_lock); num_rkeys_send = lgr->conns_num; buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst); do { @@ -1374,7 +1374,7 @@ static int smc_llc_srv_rkey_exchange(struct smc_link *link, smc_llc_flow_qentry_del(&lgr->llc_flow_lcl); } while (num_rkeys_send || num_rkeys_recv); out: - mutex_unlock(&lgr->rmbs_lock); + up_write(&lgr->rmbs_lock); return rc; } From patchwork Wed Aug 10 17:47:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940863 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 791F0C28B2C for ; Wed, 10 Aug 2022 17:48:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232753AbiHJRsF (ORCPT ); Wed, 10 Aug 2022 13:48:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232579AbiHJRsB (ORCPT ); Wed, 10 Aug 2022 13:48:01 -0400 Received: from out30-44.freemail.mail.aliyun.com (out30-44.freemail.mail.aliyun.com [115.124.30.44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 681F68C027; Wed, 10 Aug 2022 10:47:53 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvtUH8_1660153669; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvtUH8_1660153669) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:50 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 09/10] net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link() Date: Thu, 11 Aug 2022 01:47:40 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" After we optimize the parallel capability of SMC-R connection establishment, there is a certain chance to trigger the following panic: PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7 #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60 #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7 #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715 #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654 #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62 [exception RIP: ib_alloc_mr+19] RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc] #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc] #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc] The reason here is that when the server tries to create a second link, smc_llc_srv_add_link() has no protection and may add a new link to link group. This breaks the security environment protected by llc_conf_mutex. Signed-off-by: D. Wythe --- net/smc/af_smc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 39dbf39..0b0c53a 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1834,8 +1834,10 @@ static int smcr_serv_conf_first_link(struct smc_sock *smc) smc_llc_link_active(link); smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE); + down_write(&link->lgr->llc_conf_mutex); /* initial contact - try to establish second link */ smc_llc_srv_add_link(link, NULL); + up_write(&link->lgr->llc_conf_mutex); return 0; } From patchwork Wed Aug 10 17:47:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12940864 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92CF8C25B07 for ; Wed, 10 Aug 2022 17:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232482AbiHJRsP (ORCPT ); Wed, 10 Aug 2022 13:48:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232695AbiHJRsC (ORCPT ); Wed, 10 Aug 2022 13:48:02 -0400 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 038168C02E; Wed, 10 Aug 2022 10:47:53 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R331e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VLvtrne_1660153670; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VLvtrne_1660153670) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 01:47:51 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next 10/10] net/smc: fix application data exception Date: Thu, 11 Aug 2022 01:47:41 +0800 Message-Id: <2c6e99846828f7c409ec641ce047e810b89c7130.1660152975.git.alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" After we optimize the parallel capability of SMC-R connection establishment, There is a certain probability that following exceptions will occur in the wrk benchmark test: Running 10s test @ http://11.213.45.6:80 8 threads and 64 connections Thread Stats Avg Stdev Max +/- Stdev Latency 3.72ms 13.94ms 245.33ms 94.17% Req/Sec 1.96k 713.67 5.41k 75.16% 155262 requests in 10.10s, 23.10MB read Non-2xx or 3xx responses: 3 We will find that the error is HTTP 400 error, which is a serious exception in our test, which means the application data was corrupted. Consider the following scenarios: CPU0 CPU1 buf_desc->used = 0; cmpxchg(buf_desc->used, 0, 1) deal_with(buf_desc) memset(buf_desc->cpu_addr,0); This will cause the data received by a victim connection to be cleared, thus triggering an HTTP 400 error in the server. This patch exchange the order between clear used and memset, add barrier to ensure memory consistency. Signed-off-by: D. Wythe --- net/smc/smc_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index b90970a..7d42125 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1406,8 +1406,9 @@ static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb, smc_buf_free(lgr, is_rmb, buf_desc); } else { - buf_desc->used = 0; - memset(buf_desc->cpu_addr, 0, buf_desc->len); + /* memzero_explicit provides potential memory barrier semantics */ + memzero_explicit(buf_desc->cpu_addr, buf_desc->len); + WRITE_ONCE(buf_desc->used, 0); } }