[PATCH v2 0/4] arbitrary sg lists support

[Sagi Grimberg]

> I actually answered here:
> https://www.spinics.net/lists/linux-rdma/msg46412.html

Did anything progress with the debug?

> Sagi,
> As you mentioned the IO path is different in SRP and iSER so IMO we
> should start with SRP debugging. NVMf is similar to iSER (and not SRP)
> and that's why I think we can apply this patchset.

My concern is that this might be broken due to the fact that we don't
know what triggers this.

> If you want to wait till we debug SRP issue it's fine, but I can't repro
> it in my lab so it can take longer.

I'd prefer not to take a non-mandatory feature that is not guaranteed
to work.

> Lourance,
> maybe you can update your FW to the latest CX4 from our site and try to
> repro this issue ?

Laurence,

Can you please enable srp_add_one debug:

echo "func srp_add_one +p" > /sys/kernel/debug/dynamic_debug/control

In addition apply the following:
--
diff --git a/drivers/infiniband/hw/mlx5/mr.c 
b/drivers/infiniband/hw/mlx5/mr.c
index d9c6c0ea750b..040fbc387e4f 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1403,6 +1403,8 @@ mlx5_alloc_priv_descs(struct ib_device *device,
         int add_size;
         int ret;

+       WARN_ON_ONCE(ndescs > device->attr.max_fast_reg_page_list_len);
+
         add_size = max_t(int, MLX5_UMR_ALIGN - ARCH_KMALLOC_MINALIGN, 0);

         mr->descs_alloc = kzalloc(size + add_size, GFP_KERNEL);
--

Cheers,
Sagi.