Re: [SPDK] [NVMf] Invalid SQSIZE 128

[Daniel Verkamp <daniel.verkamp at intel.com>]

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On 09/28/2016 03:32 PM, Walker, Benjamin wrote:
> On Wed, 2016-09-28 at 22:11 +0000, Alex Bowden wrote:
>> It seems SQSIZE in linux-nvmf is by default set to 128 and seems to be 127 in
>> the NVMf code, but I think the RDMA driver does a +1 to it? This causes SPDK
>> to not accept the cmd.
>>
>
> You are using an old version of the kernel initiator. We reported this bug to
> the kernel
> developers and it is now fixed in the latest version (4.8).  SPDK was doing this
> correctly,
> but the kernel was not treating the value as 0's based.
>
>>
>> https://github.com/spdk/spdk/commit/a5be12c376f42108085bd9cfd06fc27818fdb6c9
>>
>>
>>
>> I suggest either changing this to ">" instead of ">=" or changing the
>> nvmf.conf.in MaxQueueDepth size to 129 by default.
>>
>>
>> Here's the error msg:
>> ***ERROR*** Invalid SQSIZE 128 (min 1, max 127)

Specifically, the fix is in these Linux kernel commits:

commit c5af8654c422cfdd8480be3a244748e18cace6c5
     nvme-rdma: fix sqsize/hsqsize per spec

commit f994d9dc28bc27353acde2caaf718222d92a3e24
     fabrics: define admin sqsize min default, per spec

The buggy version of the SQSIZE code was never in a released kernel 
version, only Linux 4.8-rc4. The final Linux 4.8 release (which is the 
first kernel release with NVMe over Fabrics support) will contain the fix.

Thanks,
-- Daniel