Re: [PATCH] Laptop-mode v7 for linux 2.6.1

[Kiko Piris]

On 12/01/2004 at 12:12, Jan De Luyck wrote:

> Patch applied, kernel built, laptop_mode activated, but my disk just doesn't 
> want to spin down... 
[...]
> But the disk never spins down. Not that I can tell, hdparm -C /dev/hda always 
> tells me active/idle, and the sdsl tool also reports 100% disk spinning...
> 
> anything else I have to activate/check?

As you don't say if you have checked it, here goes my suggestion:

First of all, you should assure there's no process doing reads [*] that
cause a cache miss (eg. daemons like postfix that check the queue every
few seconds). You can tell this running vmstat 1 and see that bi and bo
[**] stay at 0.

For example, I've observed that fetchmail (using imaps protocol, with
exim as mta) triggers a disk read that spins up the disk _always_
(regardless of what's in the cache). However, I must confess I have'nt
tracked it down (or even looked at any source code).

[*] Processes making disk writes are supposed to be "harmless", because
laptop-mode will delay those writes to disk (that's what it's supposed
to do! ;).

[**] And that's why vmstat's bo is supposed to stay at 0.

-- 
Kiko
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/