[PATCH 2/3] rdma: ratelimit error log

[Philipp Reisner]

Hi Zhengbing,

Thanks. This patch contains a coding style error. Or checkpatch.pl error.
There should be a space between the if and the opening bracket. Please run
a checkpatch.pl on your end before sending patches.

I fixed it and applied it.

Best regards,
 Philipp

On Tue, Jul 8, 2025 at 12:19 PM zhengbing.huang <
zhengbing.huang at easystack.cn> wrote:

> 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
>
>
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