Re: [PATCH RFC 4/4] btrfs: introduce new read_policy round-robin

Josef Bacik
2021-01-19T19:43:01Z

On 1/11/21 4:41 AM, Anand Jain wrote:
> Add round-robin read policy to route the read IO to the next device in the
> round-robin order. The chunk allocation and thus the stripe-index follows
> the order of free space available on devices. So to make the round-robin
> effective it shall follow the devid order instead of the stripe-index
> order.
>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> --
> RFC because: Provides terrible performance with the fio tests.
> I am not yet sure if there is any io workload or a block layer
> tuning that shall make this policy better. As of now just an
> experimental patch.
>

Just drop this one, if we can't find a reason to use it then don't bother adding
the code. The other options have real world valuable uses, so stick with those.
Thanks,

Josef