Re: [PATCH 6/6] blk-mq-debugfs: Add 'kick' operation

[Jens Axboe <axboe@kernel.dk>]

On 05/02/2017 10:23 AM, Bart Van Assche wrote:
> On Mon, 2017-05-01 at 18:24 -0600, Jens Axboe wrote:
>> On 05/01/2017 06:19 PM, Omar Sandoval wrote:
>>> On Thu, Apr 27, 2017 at 08:54:37AM -0700, Bart Van Assche wrote:
>>>> Running a queue causes the block layer to examine the per-CPU and
>>>> hw queues but not the requeue list. Hence add a 'kick' operation
>>>> that also examines the requeue list.
>>>
>>> The naming of these operations isn't super intuitive, but it makes
>>> enough sense if you know the code, I guess.
>>
>> I don't worry about that too much, but I do think it's important
>> that we have some way of knowing WHAT commands are available
>> for a given kernel, without having to consult the source. It's
>> no big deal you're running the latest and greatest debug kernels,
>> but it's a bigger issue if you're debugging kernel x.y.z for
>> a customer and you have to consult the source to find them.
>>
>> Can we include it in the show output?
> 
> Hello Jens,
> 
> Sorry but I'm afraid that including the list of supported commands in the
> 'show' output would make that output harder to read. Figuring out what the
> supported commands are is not that hard as the output below shows:
> 
> # dmesg -c >/dev/null; for d in /sys/kernel/debug/block/*/mq/state; do \
>   if [ -e "$d" ]; then echo help >$d 2>/dev/null; break; fi; done; dmesg
> blk_queue_flags_store: unsupported operation help. Use 'run', 'start' or 'kick'

Ah perfect, I missed that. That's perfectly fine, all I care about is
that there is some way to tell what the valid commands are, without
having to find the source.

-- 
Jens Axboe