From patchwork Sun Oct 23 12:43:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016209 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 D6FDCFA3744 for ; Sun, 23 Oct 2022 12:44:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230261AbiJWMoT (ORCPT ); Sun, 23 Oct 2022 08:44:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230231AbiJWMoS (ORCPT ); Sun, 23 Oct 2022 08:44:18 -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 8A7286D9D6; Sun, 23 Oct 2022 05:44:15 -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=ay29a033018045168;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJux_1666529052; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJux_1666529052) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:12 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 01/10] net/smc: remove locks smc_client_lgr_pending and smc_server_lgr_pending Date: Sun, 23 Oct 2022 20:43:53 +0800 Message-Id: <1666529042-40828-2-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 --- net/smc/af_smc.c | 41 ++---- net/smc/smc_core.c | 375 ++++++++++++++++++++++++++++++++++++++++++++++++++++- net/smc/smc_core.h | 10 ++ 3 files changed, 392 insertions(+), 34 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index e44ca70..e369ab6 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -53,13 +53,6 @@ #include "smc_tracepoint.h" #include "smc_sysctl.h" -static DEFINE_MUTEX(smc_server_lgr_pending); /* serialize link group - * creation on server - */ -static DEFINE_MUTEX(smc_client_lgr_pending); /* serialize link group - * creation on client - */ - static struct workqueue_struct *smc_tcp_ls_wq; /* wq for tcp listen work */ struct workqueue_struct *smc_hs_wq; /* wq for handshake work */ struct workqueue_struct *smc_close_wq; /* wq for close work */ @@ -1196,10 +1189,8 @@ 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; } @@ -1291,7 +1282,6 @@ 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; @@ -1301,7 +1291,6 @@ 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; @@ -1347,11 +1336,8 @@ static int smc_connect_ism(struct smc_sock *smc, } ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid; - /* there is only one lgr role for SMC-D; use server lock */ - mutex_lock(&smc_server_lgr_pending); rc = smc_conn_create(smc, ini); if (rc) { - mutex_unlock(&smc_server_lgr_pending); return rc; } @@ -1378,7 +1364,6 @@ static int smc_connect_ism(struct smc_sock *smc, aclc->hdr.version, eid, NULL); if (rc) goto connect_abort; - mutex_unlock(&smc_server_lgr_pending); smc_copy_sock_settings_to_clc(smc); smc->connect_nonblock = 0; @@ -1388,7 +1373,6 @@ static int smc_connect_ism(struct smc_sock *smc, return 0; connect_abort: smc_conn_abort(smc, ini->first_contact_local); - mutex_unlock(&smc_server_lgr_pending); smc->connect_nonblock = 0; return rc; @@ -1504,6 +1488,9 @@ static int __smc_connect(struct smc_sock *smc) SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc); smc_connect_ism_vlan_cleanup(smc, ini); + if (ini->first_contact_local) + smc_lgr_decision_maker_on_first_contact_done(ini, true /* success */); + kfree(buf); kfree(ini); return 0; @@ -1512,6 +1499,8 @@ static int __smc_connect(struct smc_sock *smc) smc_connect_ism_vlan_cleanup(smc, ini); kfree(buf); fallback: + if (ini->first_contact_local) + smc_lgr_decision_maker_on_first_contact_done(ini, false /* fail */); kfree(ini); return smc_connect_decline_fallback(smc, rc, version); } @@ -2378,7 +2367,6 @@ static void smc_listen_work(struct work_struct *work) if (rc) goto out_decl; - mutex_lock(&smc_server_lgr_pending); smc_close_init(new_smc); smc_rx_init(new_smc); smc_tx_init(new_smc); @@ -2386,18 +2374,14 @@ static void smc_listen_work(struct work_struct *work) /* determine ISM or RoCE device used for connection */ rc = smc_listen_find_device(new_smc, pclc, ini); if (rc) - goto out_unlock; + goto out_decl; /* send SMC Accept CLC message */ accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version; rc = smc_clc_send_accept(new_smc, ini->first_contact_local, accept_version, ini->negotiated_eid); if (rc) - goto out_unlock; - - /* SMC-D does not need this lock any more */ - if (ini->is_smcd) - mutex_unlock(&smc_server_lgr_pending); + goto out_decl; /* receive SMC Confirm CLC message */ memset(buf, 0, sizeof(*buf)); @@ -2405,8 +2389,6 @@ static void smc_listen_work(struct work_struct *work) rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf), SMC_CLC_CONFIRM, CLC_WAIT_TIME); if (rc) { - if (!ini->is_smcd) - goto out_unlock; goto out_decl; } @@ -2415,17 +2397,18 @@ static void smc_listen_work(struct work_struct *work) rc = smc_listen_rdma_finish(new_smc, cclc, ini->first_contact_local, ini); if (rc) - goto out_unlock; - mutex_unlock(&smc_server_lgr_pending); + goto out_decl; } smc_conn_save_peer_info(new_smc, cclc); smc_listen_out_connected(new_smc); SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini); + if (ini->first_contact_local) + smc_lgr_decision_maker_on_first_contact_done(ini, true /* success */); goto out_free; -out_unlock: - mutex_unlock(&smc_server_lgr_pending); out_decl: + if (ini && ini->first_contact_local) + smc_lgr_decision_maker_on_first_contact_done(ini, false /* fail */); 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 e6ee797..fff41c3 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -46,6 +46,282 @@ struct smc_lgr_list smc_lgr_list = { /* established link groups */ .num = 0, }; +struct smc_lgr_decision_maker { + struct rhash_head rnode; /* node for rhashtable */ + struct wait_queue_head wq; /* queue for connection that have been + * decided to wait + */ + spinlock_t lock; /* protection for decision maker */ + refcount_t ref; /* refcount for decision maker */ + int type; /* smc type */ + int role; /* smc role */ + unsigned long pending_capability; + /* maximum pending number of connections that + * need to wait. + */ + unsigned long conns_pending; + /* the number of pending connections */ + u32 lacking_first_contact; + /* indicate that the connection + * should perform first contact. + */ +}; + +struct smcr_lgr_decision_maker { + struct smc_lgr_decision_maker ldm; + 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; +}; + +struct smcd_lgr_decision_maker { + struct smc_lgr_decision_maker ldm; + u64 peer_gid; + struct smcd_dev *dev; +}; + +static int smcr_lgr_decision_maker_cmpfn(struct rhashtable_compare_arg *arg, const void *obj) +{ + const struct smc_init_info *ini = arg->key; + const struct smcr_lgr_decision_maker *rldm = obj; + + if (ini->role != rldm->ldm.role) + return 1; + + if (memcmp(ini->peer_systemid, rldm->peer_systemid, SMC_SYSTEMID_LEN)) + return 1; + + if (memcmp(ini->peer_gid, rldm->peer_gid, SMC_GID_SIZE)) + return 1; + + if ((ini->role == SMC_SERV || ini->ib_clcqpn == rldm->clcqpn) && + (ini->smcr_version == SMC_V2 || + !memcmp(ini->peer_mac, rldm->peer_mac, ETH_ALEN))) + return 0; + + return 1; +} + +static u32 smcr_lgr_decision_maker_hashfn(const void *data, u32 len, u32 seed) +{ + const struct smcr_lgr_decision_maker *rldm = data; + + return jhash2((u32 *)rldm->peer_systemid, SMC_SYSTEMID_LEN / sizeof(u32), seed) + + ((rldm->ldm.role == SMC_SERV) ? 0 : rldm->clcqpn); +} + +static u32 smcr_lgr_decision_maker_arg_hashfn(const void *data, u32 len, u32 seed) +{ + const struct smc_init_info *ini = data; + + return jhash2((u32 *)ini->peer_systemid, SMC_SYSTEMID_LEN / sizeof(u32), seed) + + ((ini->role == SMC_SERV) ? 0 : ini->ib_clcqpn); +} + +static void smcr_lgr_decision_maker_init(struct smc_lgr_decision_maker *ldm, + struct smc_init_info *ini) +{ + struct smcr_lgr_decision_maker *rldm = (struct smcr_lgr_decision_maker *)ldm; + + memcpy(rldm->peer_systemid, ini->peer_systemid, SMC_SYSTEMID_LEN); + memcpy(rldm->peer_gid, ini->peer_gid, SMC_GID_SIZE); + memcpy(rldm->peer_mac, ini->peer_mac, ETH_ALEN); + rldm->clcqpn = ini->ib_clcqpn; +} + +static int smcd_lgr_decision_maker_cmpfn(struct rhashtable_compare_arg *arg, const void *obj) +{ + const struct smc_init_info *ini = arg->key; + const struct smcd_lgr_decision_maker *dldm = obj; + + if (ini->role != dldm->ldm.role) + return 1; + + if (ini->ism_peer_gid[ini->ism_selected] != dldm->peer_gid) + return 1; + + if (ini->ism_dev[ini->ism_selected] != dldm->dev) + return 1; + + return 0; +} + +static u32 smcd_lgr_decision_maker_hashfn(const void *data, u32 len, u32 seed) +{ + const struct smcd_lgr_decision_maker *dlcm = data; + + return jhash2((u32 *)&dlcm->peer_gid, sizeof(dlcm->peer_gid) / sizeof(u32), seed); +} + +static u32 smcd_lgr_decision_maker_arg_hashfn(const void *data, u32 len, u32 seed) +{ + const struct smc_init_info *ini = data; + u64 select_gid; + + select_gid = ini->ism_peer_gid[ini->ism_selected]; + return jhash2((u32 *)&select_gid, sizeof(select_gid) / sizeof(u32), seed); +} + +static void smcd_lgr_decision_maker_init(struct smc_lgr_decision_maker *ldm, + struct smc_init_info *ini) +{ + struct smcd_lgr_decision_maker *dldm = (struct smcd_lgr_decision_maker *)ldm; + + dldm->peer_gid = ini->ism_peer_gid[ini->ism_selected]; + dldm->dev = ini->ism_dev[ini->ism_selected]; +} + +struct smc_lgr_decision_builder { + struct rhashtable map; + spinlock_t map_lock; /* protect map */ + struct rhashtable_params default_params; + /* how to serach and insert decision maker by ini */ + void (*init)(struct smc_lgr_decision_maker *ldm, struct smc_init_info *ini); + /* init maker by ini */ + u32 sz; /* size */ +}; + +static struct smc_lgr_decision_builder smc_lgr_decision_set[SMC_TYPE_D + 1] = { + /* SMC_TYPE_R = 0 */ + { + .sz = sizeof(struct smcr_lgr_decision_maker), + .init = smcr_lgr_decision_maker_init, + .map_lock = __SPIN_LOCK_UNLOCKED(smc_lgr_decision_set[SMC_TYPE_R].map_lock), + .default_params = { + .head_offset = offsetof(struct smc_lgr_decision_maker, rnode), + .key_len = sizeof(struct smc_init_info), + .obj_cmpfn = smcr_lgr_decision_maker_cmpfn, + .obj_hashfn = smcr_lgr_decision_maker_hashfn, + .hashfn = smcr_lgr_decision_maker_arg_hashfn, + .automatic_shrinking = true, + }, + }, + /* SMC_TYPE_D = 1 */ + { + .sz = sizeof(struct smcd_lgr_decision_maker), + .init = smcd_lgr_decision_maker_init, + .map_lock = __SPIN_LOCK_UNLOCKED(smc_lgr_decision_set[SMC_TYPE_D].map_lock), + .default_params = { + .head_offset = offsetof(struct smc_lgr_decision_maker, rnode), + .key_len = sizeof(struct smc_init_info), + .obj_cmpfn = smcd_lgr_decision_maker_cmpfn, + .obj_hashfn = smcd_lgr_decision_maker_hashfn, + .hashfn = smcd_lgr_decision_maker_arg_hashfn, + .automatic_shrinking = true, + }, + }, +}; + +/* hold a reference for smc_lgr_decision_maker */ +static inline void smc_lgr_decision_maker_hold(struct smc_lgr_decision_maker *ldm) +{ + if (likely(ldm)) + refcount_inc(&ldm->ref); +} + +/* release a reference for smc_lgr_decision_maker */ +static inline void smc_lgr_decision_maker_put(struct smc_lgr_decision_maker *ldm) +{ + bool do_free = false; + int type; + + if (unlikely(!ldm)) + return; + + if (refcount_dec_not_one(&ldm->ref)) + return; + + type = ldm->type; + + spin_lock_bh(&smc_lgr_decision_set[type].map_lock); + /* last ref */ + if (refcount_dec_and_test(&ldm->ref)) { + do_free = true; + rhashtable_remove_fast(&smc_lgr_decision_set[type].map, &ldm->rnode, + smc_lgr_decision_set[type].default_params); + } + spin_unlock_bh(&smc_lgr_decision_set[type].map_lock); + if (do_free) + kfree(ldm); +} + +static struct smc_lgr_decision_maker * +smc_get_or_create_lgr_decision_maker(struct smc_init_info *ini) +{ + struct smc_lgr_decision_maker *ldm; + int err, type; + + type = ini->is_smcd ? SMC_TYPE_D : SMC_TYPE_R; + + spin_lock_bh(&smc_lgr_decision_set[type].map_lock); + ldm = rhashtable_lookup_fast(&smc_lgr_decision_set[type].map, ini, + smc_lgr_decision_set[type].default_params); + if (!ldm) { + ldm = kzalloc(smc_lgr_decision_set[type].sz, GFP_ATOMIC); + if (unlikely(!ldm)) + goto fail; + + /* common init */ + spin_lock_init(&ldm->lock); + init_waitqueue_head(&ldm->wq); + refcount_set(&ldm->ref, 1); + ldm->type = type; + ldm->role = ini->role; + + /* init */ + if (smc_lgr_decision_set[type].init) + smc_lgr_decision_set[type].init(ldm, ini); + + err = rhashtable_insert_fast(&smc_lgr_decision_set[type].map, + &ldm->rnode, + smc_lgr_decision_set[type].default_params); + if (unlikely(err)) { + pr_warn_ratelimited("smc: rhashtable_insert_fast failed (%d)", err); + kfree(ldm); + ldm = NULL; + } + } else { + smc_lgr_decision_maker_hold(ldm); + } +fail: + spin_unlock_bh(&smc_lgr_decision_set[type].map_lock); + return ldm; +} + +void smc_lgr_decision_maker_on_first_contact_done(struct smc_init_info *ini, bool success) +{ + struct smc_lgr_decision_maker *ldm; + int nr; + + if (unlikely(!ini->first_contact_local)) + return; + + /* get lgr decision maker */ + ldm = ini->ldm; + + if (unlikely(!ldm)) + return; + + spin_lock_bh(&ldm->lock); + ldm->pending_capability -= (SMC_RMBS_PER_LGR_MAX - 1); + nr = SMC_RMBS_PER_LGR_MAX - 1; + if (unlikely(!success) && ldm->role == SMC_SERV) { + ldm->lacking_first_contact++; + /* only to wake up one connection to perfrom + * first contact in server side, client MUST wake up + * all to decline. + */ + nr = 1; + } + spin_unlock_bh(&ldm->lock); + if (nr) + wake_up_nr(&ldm->wq, nr); + + /* hold in smc_lgr_create */ + smc_lgr_decision_maker_put(ldm); +} + static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */ static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted); @@ -756,6 +1032,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, lnk->link_id = smcr_next_link_id(lgr); lnk->lgr = lgr; smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */ + rwlock_init(&lnk->rtokens_lock); lnk->link_idx = link_idx; lnk->wr_rx_id_compl = 0; smc_ibdev_cnt_inc(lnk); @@ -914,6 +1191,11 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) atomic_inc(&lgr_cnt); } smc->conn.lgr = lgr; + + lgr->ldm = ini->ldm; + /* smc_lgr_decision_maker_put in __smc_lgr_free() */ + smc_lgr_decision_maker_hold(lgr->ldm); + spin_lock_bh(lgr_lock); list_add_tail(&lgr->list, lgr_list); spin_unlock_bh(lgr_lock); @@ -1363,6 +1645,9 @@ static void __smc_lgr_free(struct smc_link_group *lgr) if (!atomic_dec_return(&lgr_cnt)) wake_up(&lgrs_deleted); } + /* smc_lgr_decision_maker_hold in smc_lgr_create() */ + if (lgr->ldm) + smc_lgr_decision_maker_put(lgr->ldm); kfree(lgr); } @@ -1851,11 +2136,13 @@ 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_lgr_decision_maker *ldm = 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; @@ -1863,12 +2150,24 @@ 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) + ini->role = role; + + ldm = smc_get_or_create_lgr_decision_maker(ini); + if (unlikely(!ldm)) + return SMC_CLC_DECL_INTERR; + + if (role == SMC_CLNT && ini->first_contact_peer) { + spin_lock_bh(&ldm->lock); + ldm->pending_capability += (SMC_RMBS_PER_LGR_MAX - 1); + spin_unlock_bh(&ldm->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(&ldm->lock); +again: list_for_each_entry(lgr, lgr_list, list) { write_lock_bh(&lgr->conns_lock); if ((ini->is_smcd ? @@ -1895,9 +2194,42 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) } write_unlock_bh(&lgr->conns_lock); } + /* make decision */ + if (ini->first_contact_local) { + if (ldm->pending_capability > ldm->conns_pending) { + ldm->conns_pending++; + add_wait_queue(&ldm->wq, &wait); + spin_unlock(&ldm->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(&ldm->wq, &wait); + spin_lock_bh(lgr_lock); + spin_lock(&ldm->lock); + + ldm->conns_pending--; + if (likely(timeo && !ldm->lacking_first_contact)) + goto again; + + /* lnk create failed, only server side can raise + * a new first contact. client side here will + * fallback by SMC_CLC_DECL_SYNCERR. + */ + if (role == SMC_SERV && ldm->lacking_first_contact) + ldm->lacking_first_contact--; + } + if (role == SMC_SERV) { + /* first_contact */ + ldm->pending_capability += (SMC_RMBS_PER_LGR_MAX - 1); + } + } + + spin_unlock(&ldm->lock); spin_unlock_bh(lgr_lock); if (rc) - return rc; + goto out; if (role == SMC_CLNT && !ini->first_contact_peer && ini->first_contact_local) { @@ -1905,11 +2237,15 @@ 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: if (ini->first_contact_local) { + ini->ldm = ldm; + /* smc_lgr_decision_maker_put in first_contact_done() */ + smc_lgr_decision_maker_hold(ldm); rc = smc_lgr_create(smc, ini); if (rc) goto out; @@ -1942,6 +2278,8 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) #endif out: + /* smc_lgr_decision_maker_hold in smc_get_or_create_lgr_decision_make() */ + smc_lgr_decision_maker_put(ldm); return rc; } @@ -2504,19 +2842,24 @@ int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey) u32 rkey = ntohl(nw_rkey); int i; + write_lock_bh(&lnk->rtokens_lock); for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) { if (lgr->rtokens[i][lnk->link_idx].rkey == rkey && lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr && test_bit(i, lgr->rtokens_used_mask)) { /* already in list */ + write_unlock_bh(&lnk->rtokens_lock); return i; } } i = smc_rmb_reserve_rtoken_idx(lgr); - if (i < 0) + if (i < 0) { + write_unlock_bh(&lnk->rtokens_lock); return i; + } lgr->rtokens[i][lnk->link_idx].rkey = rkey; lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr; + write_unlock_bh(&lnk->rtokens_lock); return i; } @@ -2527,6 +2870,7 @@ int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey) u32 rkey = ntohl(nw_rkey); int i, j; + write_lock_bh(&lnk->rtokens_lock); for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) { if (lgr->rtokens[i][lnk->link_idx].rkey == rkey && test_bit(i, lgr->rtokens_used_mask)) { @@ -2535,9 +2879,11 @@ int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey) lgr->rtokens[i][j].dma_addr = 0; } clear_bit(i, lgr->rtokens_used_mask); + write_unlock_bh(&lnk->rtokens_lock); return 0; } } + write_unlock_bh(&lnk->rtokens_lock); return -ENOENT; } @@ -2603,12 +2949,31 @@ static int smc_core_reboot_event(struct notifier_block *this, int __init smc_core_init(void) { + int i; + + /* init smc lgr decision maker builder */ + for (i = 0; i <= SMC_TYPE_D; i++) + rhashtable_init(&smc_lgr_decision_set[i].map, + &smc_lgr_decision_set[i].default_params); + return register_reboot_notifier(&smc_reboot_notifier); } +static void smc_lgr_decision_maker_free_cb(void *ptr, void *arg) +{ + kfree(ptr); +} + /* Called (from smc_exit) when module is removed */ void smc_core_exit(void) { + int i; + unregister_reboot_notifier(&smc_reboot_notifier); smc_lgrs_shutdown(); + + /* destroy smc lgr decision maker builder */ + for (i = 0; i <= SMC_TYPE_D; i++) + rhashtable_free_and_destroy(&smc_lgr_decision_set[i].map, + smc_lgr_decision_maker_free_cb, NULL); } diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 285f9bd..ad22751 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -107,6 +108,7 @@ struct smc_link { u32 wr_tx_cnt; /* number of WR send buffers */ wait_queue_head_t wr_tx_wait; /* wait for free WR send buf */ atomic_t wr_tx_refcnt; /* tx refs to link */ + rwlock_t rtokens_lock; struct smc_wr_buf *wr_rx_bufs; /* WR recv payload buffers */ struct ib_recv_wr *wr_rx_ibs; /* WR recv meta data */ @@ -244,6 +246,8 @@ struct smc_llc_flow { struct smc_llc_qentry *qentry; }; +struct smc_lgr_decision_maker; + struct smc_link_group { struct list_head list; struct rb_root conns_all; /* connection tree */ @@ -335,6 +339,8 @@ struct smc_link_group { /* peer triggered shutdownn */ }; }; + struct smc_lgr_decision_maker *ldm; + /* who decides to create this lgr */ }; struct smc_clc_msg_local; @@ -373,6 +379,7 @@ struct smc_init_info { unsigned short vlan_id; u32 rc; u8 negotiated_eid[SMC_MAX_EID_LEN]; + struct smc_lgr_decision_maker *ldm; /* SMC-R */ u8 smcr_version; u8 check_smcrv2; @@ -391,6 +398,7 @@ struct smc_init_info { u8 ism_offered_cnt; /* # of ISM devices offered */ u8 ism_selected; /* index of selected ISM dev*/ u8 smcd_version; + u8 role; }; /* Find the connection associated with the given alert token in the link group. @@ -559,6 +567,8 @@ 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 smc_lgr_decision_maker_on_first_contact_done(struct smc_init_info *ini, bool success); + static inline struct smc_link_group *smc_get_lgr(struct smc_link *link) { return link->lgr; From patchwork Sun Oct 23 12:43:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016205 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 02C30ECAAA1 for ; Sun, 23 Oct 2022 12:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230143AbiJWMoR (ORCPT ); Sun, 23 Oct 2022 08:44:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbiJWMoQ (ORCPT ); Sun, 23 Oct 2022 08:44:16 -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 685F16D877; Sun, 23 Oct 2022 05:44:15 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R251e4;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=8;SR=0;TI=SMTPD_---0VSpfJvR_1666529052; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJvR_1666529052) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:13 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 02/10] net/smc: fix SMC_CLC_DECL_ERR_REGRMB without smc_server_lgr_pending Date: Sun, 23 Oct 2022 20:43:54 +0800 Message-Id: <1666529042-40828-3-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" As commit 4940a1fdf31c ("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, since we already remove this 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 | 19 +++++++++++++++++++ 3 files changed, 29 insertions(+), 3 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index e369ab6..b55d9ad4 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2399,6 +2399,7 @@ static void smc_listen_work(struct work_struct *work) if (rc) goto out_decl; } + 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); @@ -2407,6 +2408,7 @@ static void smc_listen_work(struct work_struct *work) goto out_free; out_decl: + smc_conn_leave_rtoken_pending(new_smc, ini); if (ini && ini->first_contact_local) smc_lgr_decision_maker_on_first_contact_done(ini, false /* fail */); smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0, diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index fff41c3..c76e9a4 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -2182,14 +2182,19 @@ 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 ad22751..dae2983 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -253,6 +253,9 @@ 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 */ @@ -569,6 +572,22 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, void smc_lgr_decision_maker_on_first_contact_done(struct smc_init_info *ini, bool success); +static inline void smc_conn_enter_rtoken_pending(struct smc_sock *smc, struct smc_init_info *ini) +{ + struct smc_link_group *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 = smc->conn.lgr; + + if (lgr && !ini->first_contact_local) + atomic_dec(&lgr->rtoken_pendings); +} + static inline struct smc_link_group *smc_get_lgr(struct smc_link *link) { return link->lgr; From patchwork Sun Oct 23 12:43:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016207 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 2177FFA3741 for ; Sun, 23 Oct 2022 12:44:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230252AbiJWMoS (ORCPT ); Sun, 23 Oct 2022 08:44:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230216AbiJWMoR (ORCPT ); Sun, 23 Oct 2022 08:44:17 -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 18CFE5AC46; Sun, 23 Oct 2022 05:44:15 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJvc_1666529053; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJvc_1666529053) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:13 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 03/10] net/smc: allow confirm/delete rkey response deliver multiplex Date: Sun, 23 Oct 2022 20:43:55 +0800 Message-Id: <1666529042-40828-4-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 524649d..24f9488 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; } @@ -2017,7 +2008,8 @@ 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; @@ -2026,6 +2018,7 @@ static void smc_llc_rx_response(struct smc_link *link, qentry->msg.raw.hdr.common.type); break; } +free: kfree(qentry); return; assign: @@ -2184,25 +2177,98 @@ 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: + pr_warn("smc: invalid except llc msg %d.\n", 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) { + DEFINE_WAIT_FUNC(wait, smc_llc_rkey_response_wake_function); struct smc_link_group *lgr = send_link->lgr; - struct smc_llc_qentry *qentry = NULL; - int rc = 0; + long timeout = SMC_LLC_WAIT_TIME; + struct smc_wr_tx_pend_priv *priv; + struct smc_llc_qentry qentry; + struct smc_wr_tx_pend *pend; + 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; } @@ -2210,26 +2276,52 @@ 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; + DEFINE_WAIT_FUNC(wait, smc_llc_rkey_response_wake_function); + long timeout = SMC_LLC_WAIT_TIME; + struct smc_wr_tx_pend_priv *priv; + struct smc_llc_qentry qentry; + struct smc_wr_tx_pend *pend; struct smc_link *send_link; - int rc = 0; + 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 b0678a4..797dffa 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 45e9b89..a4ea215 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 Sun Oct 23 12:43:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016208 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 B270FFA3746 for ; Sun, 23 Oct 2022 12:44:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230267AbiJWMoV (ORCPT ); Sun, 23 Oct 2022 08:44:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230251AbiJWMoS (ORCPT ); Sun, 23 Oct 2022 08:44:18 -0400 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A3411B782; Sun, 23 Oct 2022 05:44:16 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R561e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJvl_1666529053; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJvl_1666529053) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:14 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 04/10] net/smc: make SMC_LLC_FLOW_RKEY run concurrently Date: Sun, 23 Oct 2022 20:43:56 +0800 Message-Id: <1666529042-40828-5-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 dae2983..234d213 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -244,6 +244,7 @@ enum smc_llc_flowtype { struct smc_llc_flow { enum smc_llc_flowtype type; struct smc_llc_qentry *qentry; + refcount_t parallel_refcnt; }; struct smc_lgr_decision_maker; diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 24f9488..700129c 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); @@ -1723,16 +1766,14 @@ 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; @@ -1759,19 +1800,16 @@ 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; @@ -1809,7 +1847,6 @@ 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) @@ -1910,7 +1947,7 @@ 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; @@ -1923,7 +1960,7 @@ 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 7e7a316..cb217793 100644 --- a/net/smc/smc_llc.h +++ b/net/smc/smc_llc.h @@ -49,6 +49,12 @@ 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 Sun Oct 23 12:43:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016210 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 EC5EBC433FE for ; Sun, 23 Oct 2022 12:44:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230284AbiJWMoX (ORCPT ); Sun, 23 Oct 2022 08:44:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230085AbiJWMoV (ORCPT ); Sun, 23 Oct 2022 08:44:21 -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 167C36E89D; Sun, 23 Oct 2022 05:44:16 -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=ay29a033018045176;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJvx_1666529054; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJvx_1666529054) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:14 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 05/10] net/smc: llc_conf_mutex refactor, replace it with rw_semaphore Date: Sun, 23 Oct 2022 20:43:57 +0800 Message-Id: <1666529042-40828-6-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 b55d9ad4..5c12cd7 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -493,7 +493,7 @@ 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; @@ -501,7 +501,7 @@ 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; } @@ -518,7 +518,7 @@ 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; @@ -535,7 +535,7 @@ 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 c76e9a4..b14ad32 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1383,10 +1383,10 @@ 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); } } @@ -1657,12 +1657,12 @@ 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); } @@ -1976,12 +1976,12 @@ 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, @@ -2041,9 +2041,9 @@ 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, @@ -2585,7 +2585,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, int i, rc = 0, cnt = 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]; @@ -2598,7 +2598,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, cnt++; } out: - mutex_unlock(&lgr->llc_conf_mutex); + up_write(&lgr->llc_conf_mutex); if (!rc && !cnt) rc = -EINVAL; return rc; diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 234d213..2a5a51b 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -306,7 +306,7 @@ 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 700129c..edb0cef 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -1236,12 +1236,12 @@ 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) @@ -1543,13 +1543,13 @@ 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); } @@ -1616,7 +1616,7 @@ 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) @@ -1650,7 +1650,7 @@ 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); } @@ -1686,7 +1686,7 @@ 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; @@ -1742,7 +1742,7 @@ 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); } @@ -2156,7 +2156,7 @@ 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->smc.sysctl_smcr_testlink_time); } From patchwork Sun Oct 23 12:43:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016211 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 AD10DFA3743 for ; Sun, 23 Oct 2022 12:44:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230288AbiJWMo0 (ORCPT ); Sun, 23 Oct 2022 08:44:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230239AbiJWMoV (ORCPT ); Sun, 23 Oct 2022 08:44:21 -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 D10966E8B9; Sun, 23 Oct 2022 05:44:17 -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=ay29a033018046051;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJw8_1666529055; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJw8_1666529055) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:15 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 06/10] net/smc: use read semaphores to reduce unnecessary blocking in smc_buf_create() & smcr_buf_unuse() Date: Sun, 23 Oct 2022 20:43:58 +0800 Message-Id: <1666529042-40828-7-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 b14ad32..48ad76b 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1383,10 +1383,10 @@ 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); } } @@ -2585,7 +2585,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, int i, rc = 0, cnt = 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]; @@ -2598,7 +2598,7 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, cnt++; } out: - up_write(&lgr->llc_conf_mutex); + up_read(&lgr->llc_conf_mutex); if (!rc && !cnt) rc = -EINVAL; return rc; From patchwork Sun Oct 23 12:43:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016212 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 C3E2DFA3741 for ; Sun, 23 Oct 2022 12:44:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230286AbiJWMoZ (ORCPT ); Sun, 23 Oct 2022 08:44:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230242AbiJWMoV (ORCPT ); Sun, 23 Oct 2022 08:44:21 -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 4980C5AC46; Sun, 23 Oct 2022 05:44:18 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R131e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJwS_1666529055; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJwS_1666529055) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:15 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 07/10] net/smc: reduce unnecessary blocking in smcr_lgr_reg_rmbs() Date: Sun, 23 Oct 2022 20:43:59 +0800 Message-Id: <1666529042-40828-8-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 5c12cd7..3bac24e 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -510,11 +510,26 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, struct smc_buf_desc *rmb_desc) { struct smc_link_group *lgr = link->lgr; + bool do_slow = false; int i, rc = 0; 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: + do_slow = true; /* protect against parallel smc_llc_cli_rkey_exchange() and * parallel smcr_link_reg_buf() */ @@ -526,7 +541,7 @@ 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) { @@ -535,7 +550,7 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, } rmb_desc->is_conf_rkey = true; out: - up_write(&lgr->llc_conf_mutex); + do_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 Sun Oct 23 12:44:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016214 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 60A28FA373F for ; Sun, 23 Oct 2022 12:44:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230305AbiJWMoi (ORCPT ); Sun, 23 Oct 2022 08:44:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230167AbiJWMo2 (ORCPT ); Sun, 23 Oct 2022 08:44:28 -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 B1410E0F; Sun, 23 Oct 2022 05:44:20 -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=ay29a033018045168;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJwj_1666529056; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJwj_1666529056) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:16 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 08/10] net/smc: replace mutex rmbs_lock and sndbufs_lock with rw_semaphore Date: Sun, 23 Oct 2022 20:44:00 +0800 Message-Id: <1666529042-40828-9-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 connection establieshment, smc_buf_get_slot() will always be invoked, 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 48ad76b..b09a3fd 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1128,8 +1128,8 @@ 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]); @@ -1375,7 +1375,7 @@ 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)) { @@ -1395,9 +1395,9 @@ 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 { @@ -1501,15 +1501,16 @@ 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); } } @@ -2328,19 +2329,19 @@ 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; } @@ -2449,13 +2450,13 @@ 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; @@ -2464,7 +2465,7 @@ static int _smcr_buf_map_lgr(struct smc_link *lnk, struct mutex *lock, goto out; } out: - mutex_unlock(lock); + up_write(lock); return rc; } @@ -2497,37 +2498,37 @@ 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; } @@ -2648,7 +2649,7 @@ 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) @@ -2696,9 +2697,9 @@ 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 */ } @@ -2772,9 +2773,9 @@ 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 2a5a51b..7771462 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -260,9 +260,9 @@ 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 edb0cef..4a010eb 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, @@ -1347,7 +1347,7 @@ 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 { @@ -1372,7 +1372,7 @@ 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 Sun Oct 23 12:44:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016215 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 A45CAECAAA1 for ; Sun, 23 Oct 2022 12:44:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230318AbiJWMoj (ORCPT ); Sun, 23 Oct 2022 08:44:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230293AbiJWMo2 (ORCPT ); Sun, 23 Oct 2022 08:44:28 -0400 Received: from out199-9.us.a.mail.aliyun.com (out199-9.us.a.mail.aliyun.com [47.90.199.9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60E5E646B; Sun, 23 Oct 2022 05:44:20 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R251e4;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=8;SR=0;TI=SMTPD_---0VSpfJx1_1666529056; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJx1_1666529056) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:17 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 09/10] net/smc: Fix potential panic dues to unprotected smc_llc_srv_add_link() Date: Sun, 23 Oct 2022 20:44:01 +0800 Message-Id: <1666529042-40828-10-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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 establish, 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. Fixes: 2d2209f20189 ("net/smc: first part of add link processing as SMC server") 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 3bac24e..8647d5e 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1829,8 +1829,10 @@ 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 Sun Oct 23 12:44:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13016213 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 34E7FC433FE for ; Sun, 23 Oct 2022 12:44:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230294AbiJWMoh (ORCPT ); Sun, 23 Oct 2022 08:44:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230292AbiJWMo2 (ORCPT ); Sun, 23 Oct 2022 08:44:28 -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 ED47DB84; Sun, 23 Oct 2022 05:44:19 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R691e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VSpfJxN_1666529057; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VSpfJxN_1666529057) by smtp.aliyun-inc.com; Sun, 23 Oct 2022 20:44:17 +0800 From: "D.Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@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 v4 10/10] net/smc: fix application data exception Date: Sun, 23 Oct 2022 20:44:02 +0800 Message-Id: <1666529042-40828-11-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> References: <1666529042-40828-1-git-send-email-alibuda@linux.alibaba.com> 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. Fixes: 1c5526968e27 ("net/smc: Clear memory when release and reuse buffer") Signed-off-by: D. Wythe --- net/smc/smc_core.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index b09a3fd..448b851 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1401,8 +1401,9 @@ 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); } } @@ -1413,19 +1414,17 @@ static void smc_buf_unuse(struct smc_connection *conn, if (!lgr->is_smcd && conn->sndbuf_desc->is_vm) { smcr_buf_unuse(conn->sndbuf_desc, false, lgr); } else { - conn->sndbuf_desc->used = 0; - memset(conn->sndbuf_desc->cpu_addr, 0, - conn->sndbuf_desc->len); + memzero_explicit(conn->sndbuf_desc->cpu_addr, conn->sndbuf_desc->len); + WRITE_ONCE(conn->sndbuf_desc->used, 0); } } if (conn->rmb_desc) { if (!lgr->is_smcd) { smcr_buf_unuse(conn->rmb_desc, true, lgr); } else { - conn->rmb_desc->used = 0; - memset(conn->rmb_desc->cpu_addr, 0, - conn->rmb_desc->len + - sizeof(struct smcd_cdc_msg)); + memzero_explicit(conn->rmb_desc->cpu_addr, + conn->rmb_desc->len + sizeof(struct smcd_cdc_msg)); + WRITE_ONCE(conn->rmb_desc->used, 0); } } }