The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build - Redhat

This is a discussion on The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build - Redhat ; I need to build a realtime kernel from either RHL9 2.4.21-4 (Enterprise) or RHL 9 2.4.20-6. The How-To for the kernel build offers a patch for Linux 2.4.20 and the kernel modules for rtlinux: * Linux-Kernel 2.4.20 http://www.kernel.org/pub/linux/kern...-2.4.20.tar.z2 * RTLinux ...

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Thread: The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build

  1. The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build

    I need to build a realtime kernel from either RHL9 2.4.21-4 (Enterprise) or RHL
    9 2.4.20-6. The How-To for the kernel build offers a patch for Linux 2.4.20 and
    the kernel modules for rtlinux:

    * Linux-Kernel 2.4.20
    http://www.kernel.org/pub/linux/kern...-2.4.20.tar.z2
    * RTLinux 3.2-pre2
    http://www.opentech.at/pub/rtlinux/r...2-pre2.tar.bz2

    I would guess that this rules out 2.4.21-4 as starting point, correct? In fact,
    I would think one would need a kernel patch corresponding to the kernel available.

    Are these patches just to bring a version to some status for a specific kernel
    build such as the rt kernel, i.e., the above patches 2.4.20 to prepare for a rt
    kernel, or can they be patches to bring say a kernel version up to another? For
    example, 2.4.20 to 2.4.21.

    Forgetting about the rtlinux build for the moment, is it possible to leap from
    say RHL 2.4.20 to Fedora-whatever with a single patch

    If I wanted to build a kernel for RHL 9 2.4.21-4 would I need to find a
    rtlinux-3.2-pre2 specifically for it. What's the relevance of 3.2?

    A less interesting question is what's the difference between RHL 9 2.4.20 and
    RHL9 2.4.21 (Enterprise)?

    --
    Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
    (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
    Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

    "I know that defies the law of gravity, but, you see, I never
    studied the law of gravity." -- Bugs Bunny

    Web Page:



  2. Re: The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build

    W. Watson wrote:
    > I need to build a realtime kernel from either RHL9 2.4.21-4 (Enterprise)
    > or RHL 9 2.4.20-6. The How-To for the kernel build offers a patch for
    > Linux 2.4.20 and the kernel modules for rtlinux:
    >
    > * Linux-Kernel 2.4.20
    > http://www.kernel.org/pub/linux/kern...-2.4.20.tar.z2
    > * RTLinux 3.2-pre2
    > http://www.opentech.at/pub/rtlinux/r...2-pre2.tar.bz2
    >
    > I would guess that this rules out 2.4.21-4 as starting point, correct?

    Not necessarily. It depends on what the patch does. If the patch just
    tweaks a bit of code that has been unchanged since 2.4.1, it's likely to
    work on just about any version. If the patch fixes a bug, or modifies a
    section of code that has been churned extensively, then it may not work.
    Unless you are told otherwise, the only kernel that you can be sure
    the patch will work on is plain old vanilla 2.4.20 which you can get
    from kernel.org or one of its mirrors. That's *not* the same as RHL9
    2.4.20-6. RedHat usually patches their kernels extensively.

    > In fact, I would think one would need a kernel patch corresponding to
    > the kernel available.
    >
    > Are these patches just to bring a version to some status for a specific
    > kernel build such as the rt kernel, i.e., the above patches 2.4.20 to
    > prepare for a rt kernel, or can they be patches to bring say a kernel
    > version up to another? For example, 2.4.20 to 2.4.21.

    It's unlikely that the rtlinux patch brings 2.4.20 up to 2.4.21. They
    would have started with 2.4.21 instead. That said, it is possible that
    the 2.4.20 patch fixes a bug in 2.4.20 that also got fixed in 2.4.21.

    > Forgetting about the rtlinux build for the moment, is it possible to
    > leap from say RHL 2.4.20 to Fedora-whatever with a single patch

    Of course. Since "patch" can do just about anything you can from the
    command line, you could "leap" to gcc 3.4.2 too. The important question
    is whether the thing you build will function properly on your system.
    For example, the 2.6 kernel differs significantly from the 2.4 kernel.
    You could apply a patch to upgrade your source from 2.4.x to 2.6.y (if
    you could find one) but there are no guarantees that a 2.6 kernel will
    work on your system.
    >
    > If I wanted to build a kernel for RHL 9 2.4.21-4 would I need to find a
    > rtlinux-3.2-pre2 specifically for it. What's the relevance of 3.2?

    It's the RTLinux version number.

    > A less interesting question is what's the difference between RHL 9
    > 2.4.20 and RHL9 2.4.21 (Enterprise)?

    One starts with the vanilla 2.4.20 source tree and patches that. The
    other starts with vanilla 2.4.21 and patches it.

  3. Re: The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build

    Allen McIntosh wrote:

    > W. Watson wrote:
    >
    >> I need to build a realtime kernel from either RHL9 2.4.21-4
    >> (Enterprise) or RHL 9 2.4.20-6. The How-To for the kernel build offers
    >> a patch for Linux 2.4.20 and the kernel modules for rtlinux:
    >>
    >> * Linux-Kernel 2.4.20
    >> http://www.kernel.org/pub/linux/kern...-2.4.20.tar.z2
    >> * RTLinux 3.2-pre2
    >> http://www.opentech.at/pub/rtlinux/r...2-pre2.tar.bz2
    >>
    >> I would guess that this rules out 2.4.21-4 as starting point, correct?

    >
    > Not necessarily. It depends on what the patch does. If the patch just
    > tweaks a bit of code that has been unchanged since 2.4.1, it's likely to
    > work on just about any version. If the patch fixes a bug, or modifies a
    > section of code that has been churned extensively, then it may not work.
    > Unless you are told otherwise, the only kernel that you can be sure the
    > patch will work on is plain old vanilla 2.4.20 which you can get from
    > kernel.org or one of its mirrors. That's *not* the same as RHL9
    > 2.4.20-6. RedHat usually patches their kernels extensively.
    >
    >> In fact, I would think one would need a kernel patch corresponding to
    >> the kernel available.
    >>
    >> Are these patches just to bring a version to some status for a
    >> specific kernel build such as the rt kernel, i.e., the above patches
    >> 2.4.20 to prepare for a rt kernel, or can they be patches to bring say
    >> a kernel version up to another? For example, 2.4.20 to 2.4.21.

    >
    > It's unlikely that the rtlinux patch brings 2.4.20 up to 2.4.21. They
    > would have started with 2.4.21 instead. That said, it is possible that
    > the 2.4.20 patch fixes a bug in 2.4.20 that also got fixed in 2.4.21.
    >
    >> Forgetting about the rtlinux build for the moment, is it possible to
    >> leap from say RHL 2.4.20 to Fedora-whatever with a single patch

    >
    > Of course. Since "patch" can do just about anything you can from the
    > command line, you could "leap" to gcc 3.4.2 too. The important question
    > is whether the thing you build will function properly on your system.
    > For example, the 2.6 kernel differs significantly from the 2.4 kernel.
    > You could apply a patch to upgrade your source from 2.4.x to 2.6.y (if
    > you could find one) but there are no guarantees that a 2.6 kernel will
    > work on your system.

    If I'm at RH 2.4.20/21 and want to get to 2.4.25 (if there is such an animal),
    then I need to find patches that make all the transitions in between, correct?
    Same for getting to 2.6? What if I wanted to get from 2.4.20/21 to RH Fedora? I
    presume Fedora is not built on the same base as RH 2.4?
    >
    >>
    >> If I wanted to build a kernel for RHL 9 2.4.21-4 would I need to find
    >> a rtlinux-3.2-pre2 specifically for it. What's the relevance of 3.2?

    >
    > It's the RTLinux version number.
    >
    >> A less interesting question is what's the difference between RHL 9
    >> 2.4.20 and RHL9 2.4.21 (Enterprise)?

    >
    > One starts with the vanilla 2.4.20 source tree and patches that. The
    > other starts with vanilla 2.4.21 and patches it.

    I was thinking of features. What does 2.4.21 offer that 2.4.20 doesn't?

    This brings up another question. What do each of the digits in 3.4.20-6 mean?



    --
    Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
    (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
    Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

    "I know that defies the law of gravity, but, you see, I never
    studied the law of gravity." -- Bugs Bunny

    Web Page:

  4. Re: The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build

    > If I'm at RH 2.4.20/21 and want to get to 2.4.25 (if there is such an
    > animal), then I need to find patches that make all the transitions in
    > between, correct?

    Well, you can upgrade *the kernel source* by patching it that way, but
    it's usually easier just to start over with the source tarball.
    > Same for getting to 2.6?

    2.6 is so different that patching is pointless.
    > What if I wanted to get from
    > 2.4.20/21 to RH Fedora?

    Huh? You are confusing distributions (Fedora) and kernel versions
    (2.4.20). Versions of Fedora come with versions of the kernel, but
    there is a whole lot more that goes into a distribution than just the
    kernel. As a rule, you can upgrade the kernel minor release number
    (i.e. 2.4.20->2.4.25) without going to a different distribution version
    (i.e. FC2 to FC3). Upgrading a major kernel release number (2.4->2.6)
    usually doesn't work unless you upgrade a lot of associated tools.
    > I presume Fedora is not built on the same base
    > as RH 2.4?

    RH 2.4? Are you confusing kernel versions and distribution versions here?

    > I was thinking of features. What does 2.4.21 offer that 2.4.20 doesn't?

    Not much. Mostly bugfixes.

  5. Re: The Version Game: RHL 9, 2.4.20-x vs 2.4.21-y for a Kernel Build

    Allen McIntosh wrote:

    >> If I'm at RH 2.4.20/21 and want to get to 2.4.25 (if there is such an
    >> animal), then I need to find patches that make all the transitions in
    >> between, correct?

    >
    > Well, you can upgrade *the kernel source* by patching it that way, but
    > it's usually easier just to start over with the source tarball.
    >
    >> Same for getting to 2.6?

    >
    > 2.6 is so different that patching is pointless.
    >
    >> What if I wanted to get from 2.4.20/21 to RH Fedora?

    >
    > Huh? You are confusing distributions (Fedora) and kernel versions
    > (2.4.20). Versions of Fedora come with versions of the kernel, but
    > there is a whole lot more that goes into a distribution than just the
    > kernel. As a rule, you can upgrade the kernel minor release number
    > (i.e. 2.4.20->2.4.25) without going to a different distribution version
    > (i.e. FC2 to FC3). Upgrading a major kernel release number (2.4->2.6)
    > usually doesn't work unless you upgrade a lot of associated tools.
    >
    >> I presume Fedora is not built on the same base as RH 2.4?

    >
    > RH 2.4? Are you confusing kernel versions and distribution versions here?

    So Fedora is a distribution. I would guess that it comes with a kernel, tools,
    desktop, and a bunch of other user friendly stuff. Is it all source? Someone
    mentioned that I should move off of RHL 9 and move onto Fedora. To me that
    sounds like essentially scrapping RHL 9 and moving to Fedora, which I assume
    contains the items mentioned in my first sentence of this paragraph. It's
    unlikely I will move off RHL 9, since I seem to have some custom applications
    that are keeping me there. I'm just trying to get a feel for how stuck I really am.

    >
    >> I was thinking of features. What does 2.4.21 offer that 2.4.20 doesn't?

    >
    > Not much. Mostly bugfixes.



    --
    Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
    (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
    Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

    "I know that defies the law of gravity, but, you see, I never
    studied the law of gravity." -- Bugs Bunny

    Web Page:

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