[laptop-mode] READAHEAD setting is doubled

[Joss Winn]

Hello,

hdparm -I /dev/sda shows power management to be set to 254, but my HDD
is still spinning down every few seconds. I was wondering if it was
related to the read-ahead settings.

In laptop-mode.conf, I have:

CONTROL_READAHEAD=1
LM_READAHEAD=3072
NOLM_READAHEAD=128

However, when I run hdparm /dev/sda I get:

readahead     = 6144 (on)

Which is exactly double the laptop-mode setting.

If I change the laptop-mode setting, then sure enough the new hdparm
reading is double whatever the new setting is.

Why is this?

Also, I wondered whether reducing the readahead settings might alter
the freezing I'm getting (see earlier post) when unplugging AC, but
this is not the case.

Thank you
Joss