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With this event queue the serialized llc_wq work queue is obsolete,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 <kgraul@xxxxxxxxxxxxx>
Reviewed-by: Ursula Braun <ubraun@xxxxxxxxxxxxx>
---
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(-)
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 @@ static void smc_llc_testlink_work(struct work_struct *work)
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 */
--
2.17.1
