Re: [PATCH] initramfs: Allow rootfs to use tmpfs instead of ramfs

From: Rob Landley
Date: Mon Jul 31 2006 - 10:34:03 EST


I am totally out of the loop here. (BusyBox has been taking up all my time
for months now...)

I thought rootfs already would be tmpfs whenever that was compiled into the
kernel, but I suspect the kernel I was looking at to come to that conclusion
wasn't vanilla. Still, that implies this isn't the first patch out there to
do this...

On Sunday 30 July 2006 2:48 pm, H. Peter Anvin wrote:
> There is some justification: embedded people would like to load
> inittmpfs and then continue running.

Yup. Embedded people who generally have no swap anyway. (Swap to flash is a
bad idea.) However, I believe what they were after was the ability to limit
the filesystem size so runaway logs don't trigger the OOM killer.

> The main issue -- which I am not sure what effect this patch has -- is
> that we would really like to move initramfs initialization even earlier
> in the kernel, so that it can include firmware loading for built-in
> device drivers, for example.

I remember this was "pending" late last year. Thought it had made it into
2.6.16 or so. I need _way_ more time to read the kernel list. (I'm 50,197
messages behind. That's just silly...)

> Thus, if this patch makes it harder to push initramfs initialization
> earlier, it's probably a bad thing. If not, the author of the patch
> really needs to explain why it works and why it doesn't add new
> dependencies to the initialization order.
>
> Saying "this is a trivial patch" and pushing it on the -stable tree
> doesn't inspire too much confidence, as initialization is subtle.

It doesn't look like -stable material to me either. It might be small enough
to add to the current -devel cycle, but that's not my call.

Is there any current documentation on the kernel's init sequence other than
reading init/main.c and friends?

> -hpa

Rob
--
Never bet against the cheap plastic solution.
-
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/