On Tue, Apr 19, 2022 at 10:56:05PM -0400, Bruce Momjian wrote:
> NVMe devices have a maximum queue length of 64k:
>
> https://blog.westerndigital.com/nvme-queues-explained/
>
> but our effective_io_concurrency maximum is 1,000:
>
> test=> set effective_io_concurrency = 1001;
> ERROR: 1001 is outside the valid range for parameter "effective_io_concurrency" (0 .. 1000)
>
> Should we increase its maximum to 64k? Backpatched? (SATA has a
> maximum queue length of 256.)
If there are demonstrable improvements with higher values, this seems
reasonable to me. I would even suggest removing the limit completely so
this doesn't need to be revisited in the future.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com