IB/iser: New receive buffer posting logic
Currently, the recv buffer posting logic is based on the transactional
nature of iSER which allows for posting a buffer before sending a PDU.
Change this to post only when the number of outstanding recv buffers
is below a water mark and in a batched manner, thus simplifying and
optimizing the data path. Use a pre-allocated ring of recv buffers
instead of allocating from kmem cache. A special treatment is given
to the login response buffer whose size must be 8K unlike the size of
buffers used for any other purpose which is 128 bytes.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
index 7092503..89b9560 100644
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -129,13 +129,23 @@
{
struct iser_device *device;
struct ib_qp_init_attr init_attr;
- int ret;
+ int ret = -ENOMEM;
struct ib_fmr_pool_param params;
BUG_ON(ib_conn->device == NULL);
device = ib_conn->device;
+ ib_conn->login_buf = kmalloc(ISER_RX_LOGIN_SIZE, GFP_KERNEL);
+ if (!ib_conn->login_buf) {
+ goto alloc_err;
+ ret = -ENOMEM;
+ }
+
+ ib_conn->login_dma = ib_dma_map_single(ib_conn->device->ib_device,
+ (void *)ib_conn->login_buf, ISER_RX_LOGIN_SIZE,
+ DMA_FROM_DEVICE);
+
ib_conn->page_vec = kmalloc(sizeof(struct iser_page_vec) +
(sizeof(u64) * (ISCSI_ISER_SG_TABLESIZE +1)),
GFP_KERNEL);
@@ -174,7 +184,7 @@
init_attr.cap.max_send_wr = ISER_QP_MAX_REQ_DTOS;
init_attr.cap.max_recv_wr = ISER_QP_MAX_RECV_DTOS;
init_attr.cap.max_send_sge = MAX_REGD_BUF_VECTOR_LEN;
- init_attr.cap.max_recv_sge = 2;
+ init_attr.cap.max_recv_sge = 1;
init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
init_attr.qp_type = IB_QPT_RC;
@@ -192,6 +202,7 @@
(void)ib_destroy_fmr_pool(ib_conn->fmr_pool);
fmr_pool_err:
kfree(ib_conn->page_vec);
+ kfree(ib_conn->login_buf);
alloc_err:
iser_err("unable to alloc mem or create resource, err %d\n", ret);
return ret;
@@ -314,7 +325,7 @@
mutex_lock(&ig.connlist_mutex);
list_del(&ib_conn->conn_list);
mutex_unlock(&ig.connlist_mutex);
-
+ iser_free_rx_descriptors(ib_conn);
iser_free_ib_conn_res(ib_conn);
ib_conn->device = NULL;
/* on EVENT_ADDR_ERROR there's no device yet for this conn */
@@ -625,6 +636,60 @@
reg->mem_h = NULL;
}
+int iser_post_recvl(struct iser_conn *ib_conn)
+{
+ struct ib_recv_wr rx_wr, *rx_wr_failed;
+ struct ib_sge sge;
+ int ib_ret;
+
+ sge.addr = ib_conn->login_dma;
+ sge.length = ISER_RX_LOGIN_SIZE;
+ sge.lkey = ib_conn->device->mr->lkey;
+
+ rx_wr.wr_id = (unsigned long)ib_conn->login_buf;
+ rx_wr.sg_list = &sge;
+ rx_wr.num_sge = 1;
+ rx_wr.next = NULL;
+
+ atomic_inc(&ib_conn->post_recv_buf_count);
+ ib_ret = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
+ if (ib_ret) {
+ iser_err("ib_post_recv failed ret=%d\n", ib_ret);
+ atomic_dec(&ib_conn->post_recv_buf_count);
+ }
+ return ib_ret;
+}
+
+int iser_post_recvm(struct iser_conn *ib_conn, int count)
+{
+ struct ib_recv_wr *rx_wr, *rx_wr_failed;
+ int i, ib_ret;
+ unsigned int my_rx_head = ib_conn->rx_desc_head;
+ struct iser_rx_desc *rx_desc;
+
+ for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
+ rx_desc = &ib_conn->rx_descs[my_rx_head];
+ rx_wr->wr_id = (unsigned long)rx_desc;
+ rx_wr->sg_list = &rx_desc->rx_sg;
+ rx_wr->num_sge = 1;
+ rx_wr->next = rx_wr + 1;
+ my_rx_head = (my_rx_head + 1) & (ISER_QP_MAX_RECV_DTOS - 1);
+ }
+
+ rx_wr--;
+ rx_wr->next = NULL; /* mark end of work requests list */
+
+ atomic_add(count, &ib_conn->post_recv_buf_count);
+ ib_ret = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
+ if (ib_ret) {
+ iser_err("ib_post_recv failed ret=%d\n", ib_ret);
+ atomic_sub(count, &ib_conn->post_recv_buf_count);
+ } else
+ ib_conn->rx_desc_head = my_rx_head;
+ return ib_ret;
+}
+
+
/**
* iser_dto_to_iov - builds IOV from a dto descriptor
*/
@@ -665,39 +730,6 @@
}
}
-/**
- * iser_post_recv - Posts a receive buffer.
- *
- * returns 0 on success, -1 on failure
- */
-int iser_post_recv(struct iser_desc *rx_desc)
-{
- int ib_ret, ret_val = 0;
- struct ib_recv_wr recv_wr, *recv_wr_failed;
- struct ib_sge iov[2];
- struct iser_conn *ib_conn;
- struct iser_dto *recv_dto = &rx_desc->dto;
-
- /* Retrieve conn */
- ib_conn = recv_dto->ib_conn;
-
- iser_dto_to_iov(recv_dto, iov, 2);
-
- recv_wr.next = NULL;
- recv_wr.sg_list = iov;
- recv_wr.num_sge = recv_dto->regd_vector_len;
- recv_wr.wr_id = (unsigned long)rx_desc;
-
- atomic_inc(&ib_conn->post_recv_buf_count);
- ib_ret = ib_post_recv(ib_conn->qp, &recv_wr, &recv_wr_failed);
- if (ib_ret) {
- iser_err("ib_post_recv failed ret=%d\n", ib_ret);
- atomic_dec(&ib_conn->post_recv_buf_count);
- ret_val = -1;
- }
-
- return ret_val;
-}
/**
* iser_start_send - Initiate a Send DTO operation
@@ -737,18 +769,17 @@
return ret_val;
}
-static void iser_handle_comp_error(struct iser_desc *desc)
+static void iser_handle_comp_error(struct iser_desc *desc,
+ struct iser_conn *ib_conn)
{
- struct iser_dto *dto = &desc->dto;
- struct iser_conn *ib_conn = dto->ib_conn;
+ struct iser_rx_desc *rx = (struct iser_rx_desc *)desc;
+ struct iser_rx_desc *rx_first = ib_conn->rx_descs;
+ struct iser_rx_desc *rx_last = rx_first + (ISER_QP_MAX_RECV_DTOS - 1);
- iser_dto_buffs_release(dto);
-
- if (desc->type == ISCSI_RX) {
- kfree(desc->data);
- kmem_cache_free(ig.desc_cache, desc);
+ if ((char *)desc == ib_conn->login_buf ||
+ (rx_first <= rx && rx <= rx_last))
atomic_dec(&ib_conn->post_recv_buf_count);
- } else { /* type is TX control/command/dataout */
+ else { /* type is TX control/command/dataout */
if (desc->type == ISCSI_TX_DATAOUT)
kmem_cache_free(ig.desc_cache, desc);
atomic_dec(&ib_conn->post_send_buf_count);
@@ -780,20 +811,25 @@
struct ib_wc wc;
struct iser_desc *desc;
unsigned long xfer_len;
+ struct iser_conn *ib_conn;
while (ib_poll_cq(cq, 1, &wc) == 1) {
desc = (struct iser_desc *) (unsigned long) wc.wr_id;
BUG_ON(desc == NULL);
+ ib_conn = wc.qp->qp_context;
if (wc.status == IB_WC_SUCCESS) {
- if (desc->type == ISCSI_RX) {
+ if (wc.opcode == IB_WC_RECV) {
xfer_len = (unsigned long)wc.byte_len;
- iser_rcv_completion(desc, xfer_len);
+ iser_rcv_completion((struct iser_rx_desc *)desc,
+ xfer_len, ib_conn);
} else /* type == ISCSI_TX_CONTROL/SCSI_CMD/DOUT */
iser_snd_completion(desc);
} else {
- iser_err("comp w. error op %d status %d\n",desc->type,wc.status);
- iser_handle_comp_error(desc);
+ if (wc.status != IB_WC_WR_FLUSH_ERR)
+ iser_err("id %llx status %d vend_err %x\n",
+ wc.wr_id, wc.status, wc.vendor_err);
+ iser_handle_comp_error(desc, ib_conn);
}
}
/* #warning "it is assumed here that arming CQ only once its empty" *