[systemd-devel] [PATCH] [RFC][PLEASE TEST] readahead: chunk on spinning media

[Tom Gundersen]

On Sat, Mar 23, 2013 at 2:16 AM, Lennart Poettering
<lennart at poettering.net> wrote:
> Then, I generally believe better than trying to be smart when reading
> things we should much rather try to place things properly on disk. We
> already defrag things based on the read order for btrfs, we should do
> the same for ext4. The API for that unfortunately awful, but e4rat has
> shown that this does work. Basically, this is what you do:

Isn't the problem that reads by blkid and friends are not being caught
by readahead-collect, and hence end up blocking until readahead-replay
has finished? In that case reordering won't help (I think).

-t