[PATCH 2/3] rdma: ratelimit error log

[zhengbing.huang]

Have a crash call trace as follow:
  ? bit_clear+0x120/0x120
  fbcon_putcs+0xe7/0x100
  fbcon_redraw.isra.20+0xfd/0x1e0
  fbcon_scroll+0x8c9/0xde0
  con_scroll+0x20b/0x220
  ? bit_clear+0x120/0x120
  lf+0xa0/0xb0
  vt_console_print+0x310/0x400
  console_unlock+0x35f/0x4a0
  vprintk_emit+0x14d/0x250
  printk+0x58/0x6f
  dtr_tx_cq_event_handler+0x895/0x8a0 [drbd_transport_rdma]
  ? sched_clock+0x5/0x10
  ? do_IRQ+0x7f/0xd0
  mlx5_eq_comp_int+0xb0/0x1d0 [mlx5_core]
  notifier_call_chain+0x47/0x70
  atomic_notifier_call_chain+0x16/0x20
  irq_int_handler+0x11/0x20 [mlx5_core]

and the code is:
(gdb) l *dtr_tx_cq_event_handler+0x894
0x3404 is in dtr_tx_cq_event_handler (.../drbd_transport_rdma.c:1935).
1930                    if (stream_nr != ST_FLOW_CTRL) {
1931                            err = dtr_repost_tx_desc(cm, tx_desc);
1932                            if (!err)
1933                                    tx_desc = NULL; /* it is in the air again! Fly! */
1934                            else
1935                                    tr_warn(transport, "repost of tx_desc failed! %d\n", err);
1936                    }

This problem is that too many logs print in irq, cause the kernel crash.

So, we ratelimit error log

Signed-off-by: zhengbing.huang <zhengbing.huang at easystack.cn>
---
 drbd/drbd_transport_rdma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drbd/drbd_transport_rdma.c b/drbd/drbd_transport_rdma.c
index 5270e503a..30edfaf96 100644
--- a/drbd/drbd_transport_rdma.c
+++ b/drbd/drbd_transport_rdma.c
@@ -1920,7 +1920,7 @@ static int dtr_handle_tx_cq_event(struct ib_cq *cq, struct dtr_cm *cm)
 			err = dtr_repost_tx_desc(cm, tx_desc);
 			if (!err)
 				tx_desc = NULL; /* it is in the air again! Fly! */
-			else
+			else if(__ratelimit(&rdma_transport->rate_limit))
 				tr_warn(transport, "repost of tx_desc failed! %d\n", err);
 		}
 	}
-- 
2.43.0