mbuf_jumbo_9k & iSCSI failing

[Ben RUBSON]

> On 26 Jun 2017, at 15:36, Andrey V. Elsukov <bu7cher at yandex.ru> wrote:
> 
> On 26.06.2017 16:29, Ben RUBSON wrote:
>> 
>>> On 26 Jun 2017, at 15:25, Andrey V. Elsukov <bu7cher at yandex.ru> wrote:
>>> 
>>> On 26.06.2017 16:27, Ben RUBSON wrote:
>>>> 
>>>>> On 26 Jun 2017, at 15:13, Andrey V. Elsukov <bu7cher at yandex.ru> wrote:
>>>>> 
>>>>> I think it is not mlxen specific problem, we have the same symptoms with
>>>>> ixgbe(4) driver too. To avoid the problem we have patches that are
>>>>> disable using of 9k mbufs, and instead only use 4k mbufs.
>>>> 
>>>> Interesting feedback Andrey, thank you !
>>>> The problem may be then "general".
>>>> So you still use large MTU (>=9000) but only allocating 4k mbufs, as a workaround ?
>>> 
>>> Yes.
>> 
>> Is it a kernel patch or a driver/ixgbe patch ?
> 
> I attached it.

Thank you !
The idea of new sysctls to enable/disable the workaround is nice.
Should be easy to modify to use with mlx4_en, waiting for Ryan specific work on this driver. 

I found a similar issue, reported date : 2013-10-28
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=183381

FreeBSD certainly needs a general solid patch !