Re: USB storage no-boot regression (bisected)

Alan Cox
2009-04-15T15:03:21Z

> SATA drives also take variable amounts of time to "show up" at boot.
> Perhaps Jeff should customize libata for your and Arjan's exact setups,
> just to help with understanding the point here. :)

Actually I would argue the reverse. The sooner we can push this so that
libata isn't blocking mounting the rootfs the better.

> The speed ups are fine (and welcome), but we really now need
> Arjan to follow-up with a patch to have the kernel *by default*
> wait a little longer for the rootfs to show up.
>
> Not forever, just a few seconds to compensate for the regression.

Why should every user suffer a slower boot and a poorer resume time ?

Instead make the root fs mounting look like this

while(my_rootfs_hasnt_appeared_and_i_am_sad()) {
wait_on(&new_disk_discovery);
}

and poke the queue whenever we add a relevant device.

That way if you are booting off an initrd you can finish the SATA probe
in parallel to getting userspace ticking over.

On what is nowdays essentially a hot plug system it all needs turning
this way up - eg RAID volumes should assemble and come online as the
drives are discovered not at some fixed point later in userspace.

Alan