Re: [PATCH] nvme: determine the number of IO queues

Keith Busch
2019-04-18T13:54:38Z

On Thu, Apr 18, 2019 at 02:21:57PM +0800, Aaron Ma wrote:
> On 4/18/19 1:33 AM, Maxim Levitsky wrote:
> >>
> >> Maybe its better to add a quirk for the broken device, which needs this?
>
> Adding quirk only makes the code more complicated.
> This patch doesn't change the default behavior.
> Only handle the NVME error code.

It does change the default behavior. If I have a degraded controller that
can't do IO in a machine with 1000's of CPUs, I have to iterate this
non-standard behavior 1000's of times before the drive is servicable
again. We currenlty figure that out in just a single try.

At least the quirks document *why* the driver is doing non-standard
behavior. We do the IO queue quirks for Macbooks, for example.

But why don't you file a bug report with the device vendor instead? Surely
a firmware fix provides the best possible outcome, and would make this
device work not only in all versions of Linux, but also every standard
compliant driver for any OS.