Re: [PATCH v2 06/16] xprtrdma: Use workqueue to process RPC/RDMA replies

[Sagi Grimberg <sagig@dev.mellanox.co.il>]

On 10/7/2015 5:48 PM, Chuck Lever wrote:
>
>> On Oct 7, 2015, at 10:39 AM, Sagi Grimberg <sagig@dev.mellanox.co.il> wrote:
>>
>> On 10/6/2015 5:59 PM, Chuck Lever wrote:
>>> The reply tasklet is fast, but it's single threaded. After reply
>>> traffic saturates a single CPU, there's no more reply processing
>>> capacity.
>>>
>>> Replace the tasklet with a workqueue to spread reply handling across
>>> all CPUs.  This also moves RPC/RDMA reply handling out of the soft
>>> IRQ context and into a context that allows sleeps.
>>
>> Hi Chuck,
>>
>> I'm probably missing something here, but do you ever schedule in
>> the workqueue context? Don't you need to explicitly schedule after
>> a jiffie or so the code works also in a non fully preemptable kernel?
>
> Each RPC reply gets its own work request. This is unlike
> the tasklet, which continues to run as long as there are
> items on xprtrdma’s global tasklet queue.

OK I understand now.

So this and the rest of the series looks good to me.

Reviewed-by: Sagi Grimberg <sagig@mellanox.com>