Re: [dm-devel] [Lsf-pc] [LSF/MM TOPIC] a few storage topics

[Jeff Moyer <jmoyer redhat com>]

Christoph Hellwig <hch infradead org> writes:

> All three filesystems use the generic mpages code for reads, so they
> all get the same (bad) I/O patterns.  Looks like we need to fix this up
> ASAP.

Actually, in discussing this with Vivek, he mentioned that read ahead
might be involved.  Sure enough, after bumping read_ahead_kb, 1MB I/Os
are sent down to the storage (for xfs anyway).

Cheers,
Jeff