Re: [PATCH 1/4] cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING

From: Frederic Weisbecker
Date: Thu Aug 16 2012 - 10:38:54 EST


On Thu, Aug 16, 2012 at 04:00:44PM +0200, Martin Schwidefsky wrote:
> On Thu, 16 Aug 2012 14:55:59 +0200
> Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote:
>
> > On Thu, Aug 16, 2012 at 07:38:17PM +1000, Benjamin Herrenschmidt wrote:
> > > On Thu, 2012-08-16 at 09:53 +0200, Martin Schwidefsky wrote:
> > > > Hmm, ok. But then the description should be reworded not to be specific to
> > > > the power architecture (the part of the message about "This also enables
> > > > accounting of stolen time on logically-partitioned systems running on IBM
> > > > POWER5-based machines.").
> > >
> > > Which is not very helpful to somebody running on a POWER6 or 7 (which
> > > also support that option just fine :-)
> > >
> > > So yes, the description should definitely be improved.
> >
> > All right. How about something like the below?
> >
> > diff --git a/init/Kconfig b/init/Kconfig
> > index 894b073..5f5f8c2 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -276,9 +276,9 @@ config VIRT_CPU_ACCOUNTING
> > accounting. This is done by reading a CPU counter on each
> > kernel entry and exit and on transitions within the kernel
> > between system, softirq and hardirq state, so there is a
> > - small performance impact. This also enables accounting of
> > - stolen time on logically-partitioned systems running on
> > - IBM POWER5-based machines.
> > + small performance impact. In the case of IBM POWER > 5, this
> > + also enables accounting of stolen time on logically-partitioned
> > + systems.
> >
> > config BSD_PROCESS_ACCT
> > bool "BSD Process Accounting"
> >
>
> VIRT_CPU_ACCOUNTING will enable steal time for s390 as well.

Ah right. Fixed below:

diff --git a/init/Kconfig b/init/Kconfig
index 894b073..c40d0fb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -276,9 +276,9 @@ config VIRT_CPU_ACCOUNTING
accounting. This is done by reading a CPU counter on each
kernel entry and exit and on transitions within the kernel
between system, softirq and hardirq state, so there is a
- small performance impact. This also enables accounting of
- stolen time on logically-partitioned systems running on
- IBM POWER5-based machines.
+ small performance impact. In the case of s390 or IBM POWER > 5,
+ this also enables accounting of stolen time on logically-partitioned
+ systems.

config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
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