From 6c8968c421e0e6bea8a78ee4fdd043d850cd5b26 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Wed, 29 Apr 2020 17:10:46 +0200 Subject: net/smc: use worker to process incoming llc messages Incoming llc messages are processed in irq tasklet context, and a worker is used to send outgoing messages. The worker is needed because getting a send buffer could result in a wait for a free buffer. To make sure all incoming llc messages are processed in a serialized way introduce an event queue and create a new queue entry for each message which is queued to this event queue. A new worker processes the event queue entries in order. And remove the use of a separate worker to send outgoing llc messages because the messages are processed in worker context already. With this event queue the serialized llc_wq work queue is obsolete, remove it. Signed-off-by: Karsten Graul Reviewed-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/smc_core.c | 4 +- net/smc/smc_core.h | 7 ++- net/smc/smc_llc.c | 142 ++++++++++++++++++++++++++++++++--------------------- net/smc/smc_llc.h | 1 + 4 files changed, 96 insertions(+), 58 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 78ccfbf6e4af..a1463da14614 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -412,7 +412,8 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT; memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer, SMC_SYSTEMID_LEN); - + INIT_LIST_HEAD(&lgr->llc_event_q); + spin_lock_init(&lgr->llc_event_q_lock); link_idx = SMC_SINGLE_LINK; lnk = &lgr->lnk[link_idx]; rc = smcr_link_init(lgr, lnk, link_idx, ini); @@ -613,6 +614,7 @@ static void smc_lgr_free(struct smc_link_group *lgr) if (lgr->lnk[i].state != SMC_LNK_UNUSED) smcr_link_clear(&lgr->lnk[i]); } + smc_llc_event_flush(lgr); if (!atomic_dec_return(&lgr_cnt)) wake_up(&lgrs_deleted); } diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 2b1960c8c8ce..6548e9a06f73 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -120,7 +120,6 @@ struct smc_link { struct smc_link_group *lgr; /* parent link group */ enum smc_link_state state; /* state of link */ - struct workqueue_struct *llc_wq; /* single thread work queue */ struct completion llc_confirm; /* wait for rx of conf link */ struct completion llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */ int llc_confirm_rc; /* rc from confirm link msg */ @@ -233,6 +232,12 @@ struct smc_link_group { DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX); /* used rtoken elements */ u8 next_link_id; + struct list_head llc_event_q; + /* queue for llc events */ + spinlock_t llc_event_q_lock; + /* protects llc_event_q */ + struct work_struct llc_event_work; + /* llc event worker */ }; struct { /* SMC-D */ u64 peer_gid; diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 2f03131c85fd..be74876a36ae 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -134,6 +134,12 @@ union smc_llc_msg { #define SMC_LLC_FLAG_RESP 0x80 +struct smc_llc_qentry { + struct list_head list; + struct smc_link *link; + union smc_llc_msg msg; +}; + /********************************** send *************************************/ struct smc_llc_tx_pend { @@ -356,46 +362,20 @@ static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16]) return rc; } -struct smc_llc_send_work { - struct work_struct work; - struct smc_link *link; - int llclen; - union smc_llc_msg llcbuf; -}; - -/* worker that sends a prepared message */ -static void smc_llc_send_message_work(struct work_struct *work) +/* schedule an llc send on link, may wait for buffers */ +static int smc_llc_send_message(struct smc_link *link, void *llcbuf) { - struct smc_llc_send_work *llcwrk = container_of(work, - struct smc_llc_send_work, work); struct smc_wr_tx_pend_priv *pend; struct smc_wr_buf *wr_buf; int rc; - if (!smc_link_usable(llcwrk->link)) - goto out; - rc = smc_llc_add_pending_send(llcwrk->link, &wr_buf, &pend); + if (!smc_link_usable(link)) + return -ENOLINK; + rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - goto out; - memcpy(wr_buf, &llcwrk->llcbuf, llcwrk->llclen); - smc_wr_tx_send(llcwrk->link, pend); -out: - kfree(llcwrk); -} - -/* copy llcbuf and schedule an llc send on link */ -static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen) -{ - struct smc_llc_send_work *wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); - - if (!wrk) - return -ENOMEM; - INIT_WORK(&wrk->work, smc_llc_send_message_work); - wrk->link = link; - wrk->llclen = llclen; - memcpy(&wrk->llcbuf, llcbuf, llclen); - queue_work(link->llc_wq, &wrk->work); - return 0; + return rc; + memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg)); + return smc_wr_tx_send(link, pend); } /********************************* receive ***********************************/ @@ -452,7 +432,7 @@ static void smc_llc_rx_add_link(struct smc_link *link, link->smcibdev->mac[link->ibport - 1], link->gid, SMC_LLC_RESP); } - smc_llc_send_message(link, llc, sizeof(*llc)); + smc_llc_send_message(link, llc); } } @@ -474,7 +454,7 @@ static void smc_llc_rx_delete_link(struct smc_link *link, /* server requests to delete this link, send response */ smc_llc_prep_delete_link(llc, link, SMC_LLC_RESP, true); } - smc_llc_send_message(link, llc, sizeof(*llc)); + smc_llc_send_message(link, llc); smc_lgr_terminate_sched(lgr); } } @@ -487,7 +467,7 @@ static void smc_llc_rx_test_link(struct smc_link *link, complete(&link->llc_testlink_resp); } else { llc->hd.flags |= SMC_LLC_FLAG_RESP; - smc_llc_send_message(link, llc, sizeof(*llc)); + smc_llc_send_message(link, llc); } } @@ -510,7 +490,7 @@ static void smc_llc_rx_confirm_rkey(struct smc_link *link, llc->hd.flags |= SMC_LLC_FLAG_RESP; if (rc < 0) llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG; - smc_llc_send_message(link, llc, sizeof(*llc)); + smc_llc_send_message(link, llc); } } @@ -522,7 +502,7 @@ static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link, } else { /* ignore rtokens for other links, we have only one link */ llc->hd.flags |= SMC_LLC_FLAG_RESP; - smc_llc_send_message(link, llc, sizeof(*llc)); + smc_llc_send_message(link, llc); } } @@ -549,21 +529,30 @@ static void smc_llc_rx_delete_rkey(struct smc_link *link, } llc->hd.flags |= SMC_LLC_FLAG_RESP; - smc_llc_send_message(link, llc, sizeof(*llc)); + smc_llc_send_message(link, llc); } } -static void smc_llc_rx_handler(struct ib_wc *wc, void *buf) +/* flush the llc event queue */ +void smc_llc_event_flush(struct smc_link_group *lgr) { - struct smc_link *link = (struct smc_link *)wc->qp->qp_context; - union smc_llc_msg *llc = buf; + struct smc_llc_qentry *qentry, *q; + + spin_lock_bh(&lgr->llc_event_q_lock); + list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) { + list_del_init(&qentry->list); + kfree(qentry); + } + spin_unlock_bh(&lgr->llc_event_q_lock); +} + +static void smc_llc_event_handler(struct smc_llc_qentry *qentry) +{ + union smc_llc_msg *llc = &qentry->msg; + struct smc_link *link = qentry->link; - if (wc->byte_len < sizeof(*llc)) - return; /* short message */ - if (llc->raw.hdr.length != sizeof(*llc)) - return; /* invalid message */ if (!smc_link_usable(link)) - return; /* link not active, drop msg */ + goto out; switch (llc->raw.hdr.common.type) { case SMC_LLC_TEST_LINK: @@ -588,6 +577,54 @@ static void smc_llc_rx_handler(struct ib_wc *wc, void *buf) smc_llc_rx_delete_rkey(link, &llc->delete_rkey); break; } +out: + kfree(qentry); +} + +/* worker to process llc messages on the event queue */ +static void smc_llc_event_work(struct work_struct *work) +{ + struct smc_link_group *lgr = container_of(work, struct smc_link_group, + llc_event_work); + struct smc_llc_qentry *qentry; + +again: + spin_lock_bh(&lgr->llc_event_q_lock); + if (!list_empty(&lgr->llc_event_q)) { + qentry = list_first_entry(&lgr->llc_event_q, + struct smc_llc_qentry, list); + list_del_init(&qentry->list); + spin_unlock_bh(&lgr->llc_event_q_lock); + smc_llc_event_handler(qentry); + goto again; + } + spin_unlock_bh(&lgr->llc_event_q_lock); +} + +/* copy received msg and add it to the event queue */ +static void smc_llc_rx_handler(struct ib_wc *wc, void *buf) +{ + struct smc_link *link = (struct smc_link *)wc->qp->qp_context; + struct smc_link_group *lgr = link->lgr; + struct smc_llc_qentry *qentry; + union smc_llc_msg *llc = buf; + unsigned long flags; + + if (wc->byte_len < sizeof(*llc)) + return; /* short message */ + if (llc->raw.hdr.length != sizeof(*llc)) + return; /* invalid message */ + + qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC); + if (!qentry) + return; + qentry->link = link; + INIT_LIST_HEAD(&qentry->list); + memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg)); + spin_lock_irqsave(&lgr->llc_event_q_lock, flags); + list_add_tail(&qentry->list, &lgr->llc_event_q); + spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags); + schedule_work(&link->lgr->llc_event_work); } /***************************** worker, utils *********************************/ @@ -626,12 +663,6 @@ out: int smc_llc_link_init(struct smc_link *link) { - struct smc_link_group *lgr = smc_get_lgr(link); - link->llc_wq = alloc_ordered_workqueue("llc_wq-%x:%x)", WQ_MEM_RECLAIM, - *((u32 *)lgr->id), - link->link_id); - if (!link->llc_wq) - return -ENOMEM; init_completion(&link->llc_confirm); init_completion(&link->llc_confirm_resp); init_completion(&link->llc_add); @@ -640,6 +671,7 @@ int smc_llc_link_init(struct smc_link *link) init_completion(&link->llc_delete_rkey); mutex_init(&link->llc_delete_rkey_mutex); init_completion(&link->llc_testlink_resp); + INIT_WORK(&link->lgr->llc_event_work, smc_llc_event_work); INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work); return 0; } @@ -663,8 +695,6 @@ void smc_llc_link_deleting(struct smc_link *link) /* called in worker context */ void smc_llc_link_clear(struct smc_link *link) { - flush_workqueue(link->llc_wq); - destroy_workqueue(link->llc_wq); complete(&link->llc_testlink_resp); cancel_delayed_work_sync(&link->llc_testlink_wrk); smc_wr_wakeup_reg_wait(link); diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h index c2c9d48d079f..9de83495ad14 100644 --- a/net/smc/smc_llc.h +++ b/net/smc/smc_llc.h @@ -61,6 +61,7 @@ int smc_llc_do_confirm_rkey(struct smc_link *link, struct smc_buf_desc *rmb_desc); int smc_llc_do_delete_rkey(struct smc_link *link, struct smc_buf_desc *rmb_desc); +void smc_llc_event_flush(struct smc_link_group *lgr); int smc_llc_init(void) __init; #endif /* SMC_LLC_H */ -- cgit v1.2.3