Low latency kernel for Quantal

[Tim Gardner]

On 05/29/2012 10:13 AM, Tim Gardner wrote:
> At UDS I committed to adding a low latency flavour to Quantal if we
> could collapse generic and virtual. It appears that we've been able to
> do so.
>
> After looking at the lowlatency kernel in Precise
> (git://kernel.ubuntu.com/themuso/ubuntu-precise-lowlatency.git) it looks
> like the required config changes are:
>
> CONFIG_HZ=1000
> CONFIG_NO_HZ=n
> CONFIG_PREEMPT=y
> CONFIG_PREEMPT_RCU=y
>
> and some other config options that get enabled as a result of the above
> changes.
>
> The only relevant code patch is 'UBUNTU: SAUCE: Made kernel irq-threaded
> by default' which changes the default behavior of forced IRQ threads to
> enabled, and adds a kernel boot parameter to override the default. I
> propose that we _not_ carry this patch in Quantal if the lowlatency
> installer can add 'threadirqs' to the grub kernel command line.
>
> Thoughts?
>
> rtg

And here is a pull request guaranteed to make your builds take longer.

The only clash that I see in the Quantal archive is with the lowlatency 
meta package. I'll have to add some 'Conflicts:' or 'Replaces:' in the 
mainline kernel meta package. Maybe I can get it removed completely 
since it was auto-synced.

rtg
-- 
Tim Gardner tim.gardner at canonical.com
-------------- next part --------------
The following changes since commit e9849ef084905c4d764a8412b67723b3d6bb0619:

  UBUNTU: Start new release (2012-05-29 06:32:22 -0700)

are available in the git repository at:

  git://kernel.ubuntu.com/rtg/ubuntu-quantal.git lowlatency

for you to fetch changes up to 384a55ce2d109c71b19078685156751601868249:

  UBUNTU: Added lowlatency flavour [i386 amd64] (2012-05-29 13:30:33 -0600)

----------------------------------------------------------------
Tim Gardner (1):
      UBUNTU: Added lowlatency flavour [i386 amd64]

 debian.master/abi/3.4.0-3.8/amd64/ignore.modules   |    1 +
 debian.master/abi/3.4.0-3.8/amd64/lowlatency       |13013 ++++++++++++++++++++
 .../abi/3.4.0-3.8/amd64/lowlatency.ignore          |    1 +
 debian.master/abi/3.4.0-3.8/i386/ignore.modules    |    1 +
 debian.master/abi/3.4.0-3.8/i386/lowlatency        |13013 ++++++++++++++++++++
 debian.master/abi/3.4.0-3.8/i386/lowlatency.ignore |    1 +
 debian.master/config/amd64/config.common.amd64     |    1 -
 debian.master/config/amd64/config.flavour.generic  |   12 +
 .../config/amd64/config.flavour.lowlatency         |   15 +
 debian.master/config/armel/config.common.armel     |    9 +
 debian.master/config/armhf/config.common.armhf     |    9 +
 debian.master/config/config.common.ubuntu          |   19 +-
 debian.master/config/i386/config.common.i386       |    1 -
 debian.master/config/i386/config.flavour.generic   |   12 +
 .../config/i386/config.flavour.lowlatency          |   15 +
 debian.master/config/powerpc/config.common.powerpc |   11 +
 debian.master/config/ppc64/config.common.ppc64     |   11 +
 debian.master/control.d/vars.lowlatency            |    6 +
 debian.master/d-i/kernel-versions.in               |    2 +
 debian.master/rules.d/amd64.mk                     |    2 +-
 debian.master/rules.d/i386.mk                      |    2 +-
 21 files changed, 26142 insertions(+), 15 deletions(-)
 create mode 100644 debian.master/abi/3.4.0-3.8/amd64/ignore.modules
 create mode 100644 debian.master/abi/3.4.0-3.8/amd64/lowlatency
 create mode 100644 debian.master/abi/3.4.0-3.8/amd64/lowlatency.ignore
 create mode 100644 debian.master/abi/3.4.0-3.8/i386/ignore.modules
 create mode 100644 debian.master/abi/3.4.0-3.8/i386/lowlatency
 create mode 100644 debian.master/abi/3.4.0-3.8/i386/lowlatency.ignore
 create mode 100644 debian.master/config/amd64/config.flavour.lowlatency
 create mode 100644 debian.master/config/i386/config.flavour.lowlatency
 create mode 100644 debian.master/control.d/vars.lowlatency