[SRU][F][PATCH 1/1] Ubuntu: [Config] CONFIG_PSI is enabled by default, but creates additional overhead on s390x, hence should be disabled by default on s390x only.

[Frank Heimes]

Hi Kleber, oh yes, the config change should only affect s390x!

Frank

On Wed, May 13, 2020 at 11:12 AM Kleber Souza <kleber.souza at canonical.com>
wrote:

> On 05.05.20 21:20, frank.heimes at canonical.com wrote:
> > From: Frank Heimes <frank.heimes at canonical.com>
> >
> > BugLink: https://bugs.launchpad.net/bugs/1876044
> >
> > PSI is always enabled in Ubuntu due to 'CONFIG_PSI_DEFAULT_DISABLED=n' /
> 'not set'.
> > This causes a performance degradation for popular workloads like web
> serving (nginx) due to additional overhead.
> > Hence IBM is requesting to change this option to yes for s390x:
> 'CONFIG_PSI_DEFAULT_DISABLED=y'.
> > CONFIG_PSI is already set to yes, and should stay.
> >
> > Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
> > ---
> >  debian.master/config/annotations          | 4 +++-
> >  debian.master/config/config.common.ubuntu | 2 +-
> >  2 files changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/debian.master/config/annotations
> b/debian.master/config/annotations
> > index dd6481141e9f..20fd9e21bc72 100644
> > --- a/debian.master/config/annotations
> > +++ b/debian.master/config/annotations
> > @@ -10316,7 +10316,9 @@ CONFIG_TASK_DELAY_ACCT
> policy<{'amd64': 'y', 'arm64': '
> >  CONFIG_TASK_XACCT                               policy<{'amd64': 'y',
> 'arm64': 'y', 'armhf': 'y', 'i386': 'y', 'ppc64el': 'y', 's390x': 'y'}>
> >  CONFIG_TASK_IO_ACCOUNTING                       policy<{'amd64': 'y',
> 'arm64': 'y', 'armhf': 'y', 'i386': 'y', 'ppc64el': 'y', 's390x': 'y'}>
> >  CONFIG_PSI                                      policy<{'amd64': 'y',
> 'arm64': 'y', 'armhf': 'y', 'i386': 'y', 'ppc64el': 'y', 's390x': 'y'}>
> > -CONFIG_PSI_DEFAULT_DISABLED                     policy<{'amd64': 'n',
> 'arm64': 'n', 'armhf': 'n', 'i386': 'n', 'ppc64el': 'n', 's390x': 'n'}>
> > +CONFIG_PSI_DEFAULT_DISABLED                     policy<{'amd64': 'n',
> 'arm64': 'n', 'armhf': 'n', 'i386': 'n', 'ppc64el': 'n', 's390x': 'y'}>
>
> Hi Frank,
>
> The annotations file is being changed only for s390x but the config change
> below will affect all architectures. Should the config change be applied
> only to 'debian.master/config/s390x/config.common.s390x'?
>
>
> Kleber
>
> > +
> > +CONFIG_PSI_DEFAULT_DISABLED                     mark<LP:1876044>
> >
> >  # Menu: General setup >> CPU/Task time and stats accounting >> Cputime
> accounting
> >  CONFIG_TICK_CPU_ACCOUNTING                      policy<{'amd64': 'y',
> 'arm64': 'y', 'armhf': 'y', 'i386': 'y', 'ppc64el': 'y', }>
> > diff --git a/debian.master/config/config.common.ubuntu
> b/debian.master/config/config.common.ubuntu
> > index f502f2bdfa07..115590e89d73 100644
> > --- a/debian.master/config/config.common.ubuntu
> > +++ b/debian.master/config/config.common.ubuntu
> > @@ -7567,7 +7567,7 @@ CONFIG_PSAMPLE=m
> >  CONFIG_PSERIES_CPUIDLE=y
> >  CONFIG_PSERIES_ENERGY=m
> >  CONFIG_PSI=y
> > -# CONFIG_PSI_DEFAULT_DISABLED is not set
> > +CONFIG_PSI_DEFAULT_DISABLED=y
> >  # CONFIG_PSTORE_842_COMPRESS is not set
> >  CONFIG_PSTORE_COMPRESS=y
> >  CONFIG_PSTORE_COMPRESS_DEFAULT="deflate"
> >
>
>
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