Not logged in
Log in now
Create an account
Subscribe to LWN
LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
PostgreSQL 9.3 beta: Federated databases and more
LWN.net Weekly Edition for May 9, 2013
(Nearly) full tickless operation in 3.10
Sure, they influence each other, but they are NOT the same.
Meeks: Linux on the (consumer) Desktop
Posted Sep 13, 2012 4:59 UTC (Thu) by bojan (subscriber, #14302)
Posted Sep 13, 2012 5:19 UTC (Thu) by Cyberax (✭ supporter ✭, #52523)
Posted Sep 13, 2012 5:46 UTC (Thu) by bojan (subscriber, #14302)
Sure, they do put some stuff that is not in Fedora in RHEL. But they are far from being idiots, so they reuse vast majority of _already_ _tested_ code from Fedora.
Here is a good article for you to read:
Quote from it:
"The size and expertise of the Fedora community make Fedora an ideal incubator and proving ground for features that eventually get incorporated into Red Hat Enterprise Linux. To meet the quality and reliability requirements that make Red Hat Enterprise Linux the choice for mission-critical applications, Red Hat puts Red Hat Enterprise Linux through its own set of tests and quality assurance (QA) processes that are separate and distinct from those of Fedora."
I hope you are not suggesting that Red Hat engineers "rewrite" those features for RHEL just to make it different.
Posted Sep 13, 2012 5:52 UTC (Thu) by Cyberax (✭ supporter ✭, #52523)
That stabilization work makes it special. And it's not available to the public for exactly the same reasons - community does not help much in this case.
Posted Sep 13, 2012 6:13 UTC (Thu) by bojan (subscriber, #14302)
Well, yes. And I agreed with you there.
> However, RHEL kernel is very clearly NOT branched off of Fedora's kernel.
So, your theory is that Red Hat have a completely independent RHEL tree in house and they have some secret society test just those kernels for years, before they become real RHEL kernels. I think you are mistaken. They would not have enough man power or wide enough configurations available for that. Their "super stable" RHEL kernels would suck big time if they did that.
Instead, Red Hat let new kernels into Fedora for community to test (for instance, people running F-17 are testing 3.5.x for them right now, people running F-18 what will become 3.6.x etc.). Then, at some point, dictated by internal release schedules of RHEL (i.e. the mysterious dates RH employees sometimes slip into public domain), they branch that off and start stabilisation work, based on various patches from older/newer development.
Otherwise, what's the point of having Fedora? They are not doing it only out of being nice, I am pretty certain of that.
Posted Sep 13, 2012 6:21 UTC (Thu) by Cyberax (✭ supporter ✭, #52523)
Case in point: RHEL 6 which was released on 2010-11-10 is based on 2.6.32 which was released on 2009-12-03 (and that's unusually quick turnaround for RHEL).
And they're supporting it until 2018 (at least), with backports of new features and bugfixes.
>I think you are mistaken. They would not have enough man power or wide enough configurations available for that. Their "super stable" RHEL kernels would suck big time if they did that.
They employ a lot of kernel developers precisely for that very purpose.
And that's the reason why RedHat is a big company.
Posted Sep 13, 2012 6:27 UTC (Thu) by bojan (subscriber, #14302)
Branched off what exactly? Fedora, of course.
Posted Sep 13, 2012 6:29 UTC (Thu) by Cyberax (✭ supporter ✭, #52523)
But by the time they start a new development cycle, Fedora is already several kernel versions in the future.
Posted Sep 13, 2012 6:45 UTC (Thu) by rahulsundaram (subscriber, #21946)
Where did you get that idea?
Posted Sep 13, 2012 7:02 UTC (Thu) by bojan (subscriber, #14302)
* Fri Jul 07 2006 <name> <email>
- Unified rhel and fedora srpm
> Actually, no. They begin with the mainline kernel and start applying patches on top of it. Some of these patches, of course, were in Fedora.
This is just playing semantic games. All the patches that Red Hat do on recent mainline kernels end up in Fedora, which are then (attempted to be) pushed upstream. So, by the time this RHEL kernel is based on some x.y.z upstream release, many of those Fedora patches won't even apply (because they are already part of mainline). Of course, features that RH decide not to support in RHEL (that would be the streamlining thing I was talking about) will not appear, will not be patched and will not be compiled.
> But by the time they start a new development cycle, Fedora is already several kernel versions in the future.
I do not see why that would be surprising at all. And, of course, this is where the "trunk" of new RHEL is being forged: by applying Fedora specific patches, testing them in the wild, getting feedback and pushing them upstream. This is how they _leverage_ the community. If they did not do that, that would be really stupid. And I think Red Hat's balance sheet speaks volumes about them not being stupid.
PS. If you are trying to suggest that RHEL kernel is physically not a branch of some SCM Fedora system, then you may even be correct. But, that is not what I was talking about when describing the non-secretive trunk of the Red Hat's distro development.
Posted Sep 13, 2012 7:30 UTC (Thu) by bojan (subscriber, #14302)
Just downloaded a RHEL6 kernel SRPM. The spec file mentions the word "fedora" (case insensitive) in 12 lines. So, even technically, you are probably wrong.
Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds