Re: 37.5% boot time reduction in Lenny is possible (recipe)
On Mon, Jun 02, 2008 at 09:34:09PM +0200, Petter Reinholdtsen wrote:
> The provided boot sequence look sane enough, but there are quite a lot
> of scripts I do not recognize. The sequence is not reordered based on
> dependencies and thus not fit for concurrent booting. Did you run
> parallel booting with this sequence, or did you enable insserv first?
> Parallel booting do not work without reordering based on dependencies.
> The sequence numbers used in many packages do not reflect their
> dependencies, as not all scripts with the same sequence number can
> start in parallel.
I used that order yes, since it seemed it would run all scripts with the
same number in parallel.
The unrecognized scripts are probably some of our own for detecting the
hardware modules present and validating that against was expected to
detect failed hardware or misconfigurations and such.
> Running /usr/share/insserv/check-initd-order from the insserv package
> might warn for some of these, but it ignore those that happen to get
> the correct ordering with non-parallel booting because of ascii
> sorting of the script.
I might try that out too.
Unfortunately some things just have to wait for other things to start,
and some things take a few seconds to start all by themselves, which is
hard to change. Programming an FGPA through jtag can take 3 or 4
seconds, and if you need the FPGA up to access some hardware, you have
to wait for it.
I still wonder how hard it would be to replace the BIOS with openbios or
linuxbios and whether that could reduce the 20 to 30 seconds the BIOS
takes before hitting grub.