Re: [PATCH] mm: add config for readahead window

[Andrew Morton]

On Fri, 16 Mar 2018 11:25:08 -0700 Wei Wang <wvw@xxxxxxxxxx> wrote:

> Change VM_MAX_READAHEAD value from the default 128KB to a configurable
> value. This will allow the readahead window to grow to a maximum size
> bigger than 128KB during boot, which could benefit to sequential read
> throughput and thus boot performance.

You can presently run ioctl(BLKRASET) against the block device?