Re: USB storage no-boot regression (bisected)

[Alan Cox]

> 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
--
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/