lkml.org 
[lkml]   [2007]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    SubjectRe: [PATCH 3/3] Time to make CONFIG_PARAVIRT non-experimental.
    From
    Date
    On Tue, 2007-09-18 at 23:52 +0200, Andi Kleen wrote:
    > On Tuesday 18 September 2007 23:34, Rusty Russell wrote:
    > > How about a "select" based on Xen, lguest or VMI? There's no other
    > > reason to enable it, after all.
    >
    > I did an patch to do that recently because the current setup
    > is indeed unobvious.
    >
    > But I had to drop it again because
    > it ended up with Kconfig warnings. about undefined symbols
    > on x86-64. The problem is that lguest
    > is visible in Kconfig for all architectures and it warns
    > if you select something that doesn't exist on all architectures.

    I think that's fixed as a side-effect of this cleanup. At least, it
    works for me on x86-64. Patch below: if you agree, I'll re-xmit all
    three.

    > > > Also I would still consider it experimental.
    > >
    > > After 9 months in mainline and three kernel versions,
    >
    > Well it changed a lot each release.

    Well, the biggest change was the patching code getting enhanced in
    2.6.22 (to cover all calls, not just 5). The 22 -> 23 changes were
    fairly trivial.

    So I think 2.6.24 is a reasonable time to remove EXPERIMENTAL.

    > > I'd hope not.
    > > It's been pretty damn stable (ok, you broke it once, but maybe that's
    > > because you consider it experimental).
    >
    > Is there a significant user base?

    It's enabled in Ubuntu Feisty (2.6.20).

    > At least the Xen port seems to have specific requirements
    > and essentially only work on xen-unstable (?) [or at least
    > some very new Xen version] which probably very few
    > people use.

    Sure, and that might well still be experimental (Jeremy?). But that's
    not CONFIG_PARAVIRT.

    Hope that helps,
    Rusty.
    ==
    Andi points out that PARAVIRT is an option best selected when needed.

    We introduce PARAVIRT_GUEST for the menu itself, and select PARAVIRT
    if they ask for anything which needs it. This also makes PARAVIRT
    non-experimental.

    Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

    diff -r 8efa5fdb22d8 arch/i386/Kconfig
    --- a/arch/i386/Kconfig Wed Sep 19 11:23:18 2007 +1000
    +++ b/arch/i386/Kconfig Wed Sep 19 11:33:59 2007 +1000
    @@ -214,24 +214,30 @@ config X86_ES7000

    endchoice

    -menuconfig PARAVIRT
    +config PARAVIRT
    + bool
    + depends on !(X86_VISWS || X86_VOYAGER)
    + help
    + This changes the kernel so it can modify itself when it is run
    + under a hypervisor, potentially improving performance significantly
    + over full virtualization. However, when run without a hypervisor
    + the kernel is theoretically slower and slightly larger.
    +
    +menuconfig PARAVIRT_GUEST
    - bool "Paravirtualized guest support (EXPERIMENTAL)"
    - depends on EXPERIMENTAL
    + bool "Paravirtualized guest support"
    - depends on !(X86_VISWS || X86_VOYAGER)
    - help
    - Paravirtualization is a way of running multiple instances of
    - Linux on the same machine, under a hypervisor. This option
    - changes the kernel so it can modify itself when it is run
    - under a hypervisor, improving performance significantly.
    - However, when run without a hypervisor the kernel is
    - theoretically slower. If in doubt, say N.
    -
    -if PARAVIRT
    + help
    + Say Y here to get to see options related to running Linux under
    + various hypervisors. This option alone does not add any kernel code.
    +
    + If you say N, all options in this submenu will be skipped and disabled.
    +
    +if PARAVIRT_GUEST

    source "arch/i386/xen/Kconfig"

    config VMI
    bool "VMI Guest support"
    + select PARAVIRT
    help
    VMI provides a paravirtualized interface to the VMware ESX server
    (it could be used by other hypervisors in theory too, but is not
    @@ -239,6 +246,7 @@ config VMI

    config LGUEST_GUEST
    bool "Lguest guest support"
    + select PARAVIRT
    depends on !X86_PAE
    help
    Lguest is a tiny in-kernel hypervisor. Selecting this will
    diff -r 8efa5fdb22d8 arch/i386/xen/Kconfig
    --- a/arch/i386/xen/Kconfig Wed Sep 19 11:23:18 2007 +1000
    +++ b/arch/i386/xen/Kconfig Wed Sep 19 11:25:07 2007 +1000
    @@ -4,6 +4,7 @@

    config XEN
    bool "Xen guest support"
    + select PARAVIRT
    depends on X86_CMPXCHG && X86_TSC && !NEED_MULTIPLE_NODES
    help
    This is the Linux Xen port. Enabling this will allow the

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-09-19 03:57    [W:0.029 / U:0.284 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site