linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* Error while enabling io_poll for NVMe SSD
@ 2019-03-18 22:14 Nikhil Sambhus
  2019-03-18 22:21 ` Keith Busch
  0 siblings, 1 reply; 3+ messages in thread
From: Nikhil Sambhus @ 2019-03-18 22:14 UTC (permalink / raw)
  To: linux-block

Hi,

On a Linux Kernel 5.0.0+ machine (Ubuntu 16.04)  I am using the
following command as a root user to enable polling for a NVMe SSD
device.

# echo 1 > /sys/block/nvme2n1/queue/io_poll

I get the following error:

bash: echo: write error: Invalid argument

The current value of io_poll is 0.
-- 
Regards,
Nikhil P Sambhus

"To bug is human, to debug is divine"

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Error while enabling io_poll for NVMe SSD
  2019-03-18 22:14 Error while enabling io_poll for NVMe SSD Nikhil Sambhus
@ 2019-03-18 22:21 ` Keith Busch
  2019-03-19 14:36   ` Nikhil Sambhus
  0 siblings, 1 reply; 3+ messages in thread
From: Keith Busch @ 2019-03-18 22:21 UTC (permalink / raw)
  To: Nikhil Sambhus; +Cc: linux-block

On Mon, Mar 18, 2019 at 06:14:01PM -0400, Nikhil Sambhus wrote:
> Hi,
> 
> On a Linux Kernel 5.0.0+ machine (Ubuntu 16.04)  I am using the
> following command as a root user to enable polling for a NVMe SSD
> device.
> 
> # echo 1 > /sys/block/nvme2n1/queue/io_poll
> 
> I get the following error:
> 
> bash: echo: write error: Invalid argument
> 
> The current value of io_poll is 0.

Be sure to turn on the polling queues in the nvme driver. There are none
by default. The kernel parameter to that enable them is:

  nvme.poll_queues=X

Where 'X' is the number of polling queues. I'd recommend at least 1 per
CPU socket, but more is better.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Error while enabling io_poll for NVMe SSD
  2019-03-18 22:21 ` Keith Busch
@ 2019-03-19 14:36   ` Nikhil Sambhus
  0 siblings, 0 replies; 3+ messages in thread
From: Nikhil Sambhus @ 2019-03-19 14:36 UTC (permalink / raw)
  To: Keith Busch; +Cc: linux-block

Thanks, it worked!

On Mon, Mar 18, 2019 at 6:20 PM Keith Busch <kbusch@kernel.org> wrote:
>
> On Mon, Mar 18, 2019 at 06:14:01PM -0400, Nikhil Sambhus wrote:
> > Hi,
> >
> > On a Linux Kernel 5.0.0+ machine (Ubuntu 16.04)  I am using the
> > following command as a root user to enable polling for a NVMe SSD
> > device.
> >
> > # echo 1 > /sys/block/nvme2n1/queue/io_poll
> >
> > I get the following error:
> >
> > bash: echo: write error: Invalid argument
> >
> > The current value of io_poll is 0.
>
> Be sure to turn on the polling queues in the nvme driver. There are none
> by default. The kernel parameter to that enable them is:
>
>   nvme.poll_queues=X
>
> Where 'X' is the number of polling queues. I'd recommend at least 1 per
> CPU socket, but more is better.



-- 
Regards,
Nikhil P Sambhus

"To bug is human, to debug is divine"

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-03-19 14:37 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-03-18 22:14 Error while enabling io_poll for NVMe SSD Nikhil Sambhus
2019-03-18 22:21 ` Keith Busch
2019-03-19 14:36   ` Nikhil Sambhus

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).