Re: lowmemory android driver not needed?

From: KOSAKI Motohiro
Date: Fri Jan 16 2009 - 06:17:09 EST


Hi

>> > And there is one more lowmem driver developed by Nokia for Nokia 8xx
>> > tablets it seems. CCed Tony Lindgren, Juha and Viktor.
>> >
>> > http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap-2.6.git;a=blob;f=security/lowmem.c;h=ae78a530af39703e335ad769f1e6f097f63ec6dd;hb=HEAD
>>
>> As we can't stack LSMs, using the lsm interface for a simple memory
>> driver seems pretty wasteful :)
>>
> The heuristics and tunables are more what ended up being useful with this
> module, which could trivially be abstracted out. The focus of the lowmem
> module was mostly giving userspace an opportunity to change its behaviour,
> and to try to save critical state. I don't know how well this would map
> to the Android use cases, though.

This thread is very interesting.

As far as I know, embedded guys strong want to lowmem notification mecanism.
At least, I and my mem_notify receive multiple contact from embedded
and JavaVM developer.
(include sun javavm engineer)

In ideal, I think linux MM should care this requirement directly.
LSM and driver notifier is easy breakable because these component
deeply depend on MM.

(eg, I developed /dev/mem_notify patch last year. but this patch don't
work on 2.6.28 because
split-lru patch series totally changed MM reclaim processing.)

Unfortunately, we don't have any consensus of memory notification requirement.
various people have various requirement. so, if I can discuss it and
we get consensus, I'm glad.
--
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/