Re: compression support in kmod
On 12/29/2016 11:47 PM, Christoph Biedl wrote:
> Eduard Bloch wrote...
>
>> I volunteer as test subject for that experiment. I would appreciate even
>> small steps, considering the current laptop in front of me with average
>> magnetic HDD. Over a minute boot time, which is insane and IMHO mostly
>> caused by the storm of IO operations required nowadays.
>
> At the risk of damping your expectations - I was surprised if there was
> as noticeable improvement. Perhaps on broken (i.e. slow) bootloaders
> where a smaller initrd gets loaded faster.
Note that compression support in kmod will not help initramfs, as they
are always compressed anyway - at least in the default setting in
Debian.
Compression could reduce the size of the modules loaded during boot
_after_ the initramfs has given up control - but since the problem
with HDDs is seek time, I have my doubts whether compression for
modules will actually improve that on HDDs; while the totality of
modules may be quite large nowadays (and we might want to compress
them to save space on /), the individual module files are not that
large, and the seek times are so horrible only because one needs
to load so many of them.
Furthermore I doubt that module loading is going to be the main
culprit for I/O during boot - consider how much stuff has to be
read from disk these days for userspace applications.
tl;dr: I don't think compression modules will increase boot times
on HDDs in any significant manner, but it may be a good idea to
support that just to reduce the amount of space required on disk.
Regards,
Christian
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