[v2] [PATCH 0/2] Populate rootfs asynchronously and early

Andy Whitcroft apw at canonical.com
Tue Dec 8 21:14:50 GMT 2009


On Tue, Dec 08, 2009 at 07:42:47PM +0000, Scott James Remnant wrote:

> Part of the original goal of the initramfs was that the kernel might
> actually want to call out to it for its own init purposes before
> actually passing over to it's real init.
> 
> Their usual example is things like firmware loading, or that crazy
> kernel-calls-modprobe stuff that won me the Dell Tablet :p
> 
> 
> The simple fact is that it never worked, because there's more to making
> the initramfs *ready* than just unpacking it.  We need filesystems
> like /proc and /sys mounted in it, we need to run depmod inside it (so
> that modprobe works), you need udev running to process firmware
> requests, etc.
> 
> 
> Having populate_rootfs() synchronous makes sense for the *original*
> design goals of the initramfs (vs. initrd).  However since no userspace
> ever implemented it that way, and things have moved on since then with
> regards to kernel/userspace communication, if you were doing it now
> you'd make it async.  Which we've done.
> 
> This may take some arguing upstream.
> 
> Plus you can guarantee that certain Dutch-born Intel people will stick
> their oar in about how it's not worth accepting the patch because you
> shouldn't have an initramfs anyway.

Yeah, the nice thing about the _domain approach is that the first
consumer of the initramfs can wait for it then.

The other thing we can do is to make this a configurable option so that
distros can opt-in as appropriate.

-apw



More information about the kernel-team mailing list