Re: v2.6 vs v3.0

james
2002-09-29T19:50:19Z

Upon thinking about 2.6 v3.0 argument, I think we may be looking at this
version comparison in the wrong light, it is not wether we have come far
enough from 2.4.x to make it 3.0 it is wether we have change enough from
version 2.0.x.

When I compare running linux 2.0.x to running what will be the next version we
are looking at a completely different system. For example in v2.0 the only
file system choices were ext2 or DOS, with a few others that wern't in wide
spread use. where you created small partitions to keep fsck's fast, even if
you had battery backup, you were still basicly limited to 8 gig file systems.
Today we have ext2, ext3, reiserfs, JFS, XFS, in the last four, journaling
capabilities. it is possible and expected have huge filesystems and patches
exist to break the 2 terabyte file systems exist in various stages of
testing. Not to mention we have LVM, and raid file systems, being used on
desktop as well server systems.

Networking has changed as well, we went from mostly 10mbit eternet cards and a
few 100 mbit cards, to now having 100mbit ethernet as the base of home
networking, not to mention gigabit ethernet, and ATM gaining popularity in
the server market, while they are just drivers, the real shift of thinking
comes in zero copy file transfer and a mature state of the art
firewalling/routing/bridging etc. in NAT and iptables

For video we changed from base VGA video text and X, to acellerated video
processors not just in X, but in framebuffers used as consoles.

We also have support for diverse set of buses, that change the way we think
about our system, multiple bridges on PCI, USB v1 and v2, to firewire.

I will let others more in the know in memory management, discuss the finer
points of this one, but it is a major change, in 2.0 we just killed random
programs when out of memory. today we make a slightly more educated guess as
what to kill when we are out of memory, not to mention a just one base mix of
address support, I think it was 2gig user and 2gig, Today we can choose, 1.
2, or 3 gig of kernel space. Large memory support in the Kernel , supporting
36bit memory accessing, That support more memory than I will ever see in the
near future.

we have changed from a System that barely supported smp with 2 processors with
basicly one big kernel lock to a system with finely grained locks and
semaphores and subsystem spinlocks, that has decent performance on 8+ cpu
systems. Numa system surport also appeared since version 2.0.x

In 2.0.0 we had a 15bit pid with a maximum of 1000 active ( i beleve it is
less than this) today we have a 32+bit pid on the table with support of many
more active processes. of couse we have numourous internal file systems that
did not exist, tmpfs, devfs, etc..... and changed the way we all think about
our systems.

A prempted kernel, need I say more.

well that is just a small list of the globals systems that change the way we
think of linux.

If we continue to justify major version changes based on change in minor
version to minor version, can we expect linux 2.98,x in the future? In each
minor version we rewrite one or two subsytems. And these take many months to
plan, complete and test, so big enough change in a single minor version
number to minor version may not be possible at the current size of this
devolement effort, So yes we have come far enougth from v2.0.x to justify a
version 3.0.x. If I was a marketing person I would call it linux 3.0.0
enterprize edition, if we can get LVM2, raid and break the 2 terabyte
filesystem limit along with what we allready have accomplised.

Just my opionion

James