We pre-allocate our send-queues and might overflow them
in case we have multi work-request operations which tend
to occur for large RDMA transfers over devices with limited
allowed sg elements. When we get to a queue-full condition
we might retry again later, so track our receive buffers
so we don't repost them for a retry case.
Reported-by: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Tested-by: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
---
Nic, this goes on top of your tri-patch series that
takes care of queue full handling. it pairs with
patch 3/3 "iser-target: Fix queue-full response handling"
Thanks!
drivers/infiniband/ulp/isert/ib_isert.c | 12 ++++++++++++
drivers/infiniband/ulp/isert/ib_isert.h | 3 ++-
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 9b33c0c97468..fcbed35e95a8 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -817,6 +817,7 @@ isert_post_recvm(struct isert_conn *isert_conn, u32 count)
rx_wr->sg_list = &rx_desc->rx_sg;
rx_wr->num_sge = 1;
rx_wr->next = rx_wr + 1;
+ rx_desc->in_use = false;
}
rx_wr--;
rx_wr->next = NULL; /* mark end of work requests list */
@@ -835,6 +836,15 @@ isert_post_recv(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc)
struct ib_recv_wr *rx_wr_failed, rx_wr;
int ret;
+ if (!rx_desc->in_use) {
+ /*
+ * if the descriptor is not in-use we already reposted it
+ * for recv, so just silently return
+ */
+ return 0;
+ }
+
+ rx_desc->in_use = false;
rx_wr.wr_cqe = &rx_desc->rx_cqe;
rx_wr.sg_list = &rx_desc->rx_sg;
rx_wr.num_sge = 1;
@@ -1397,6 +1407,8 @@ isert_recv_done(struct ib_cq *cq, struct ib_wc *wc)
return;
}
+ rx_desc->in_use = true;
+
ib_dma_sync_single_for_cpu(ib_dev, rx_desc->dma_addr,
ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index c02ada57d7f5..87d994de8c91 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -60,7 +60,7 @@
#define ISER_RX_PAD_SIZE (ISCSI_DEF_MAX_RECV_SEG_LEN + 4096 - \
(ISER_RX_PAYLOAD_SIZE + sizeof(u64) + sizeof(struct ib_sge) + \
- sizeof(struct ib_cqe)))
+ sizeof(struct ib_cqe) + sizeof(bool)))
#define ISCSI_ISER_SG_TABLESIZE 256
@@ -85,6 +85,7 @@ struct iser_rx_desc {
u64 dma_addr;
struct ib_sge rx_sg;
struct ib_cqe rx_cqe;
+ bool in_use;
char pad[ISER_RX_PAD_SIZE];
} __packed;
--
2.7.4
--
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