From mboxrd@z Thu Jan  1 00:00:00 1970
From: christoffer.dall@linaro.org (Christoffer Dall)
Date: Wed, 2 Dec 2015 19:07:41 +0100
Subject: arm64 sched_clock cpu accounting
In-Reply-To: <564D31D3.5040207@samsung.com>
References: <564CD5A7.8000007@samsung.com>
 <564D31D3.5040207@samsung.com>
Message-ID: <20151202180741.GR18376@cbox>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Mario,

On Wed, Nov 18, 2015 at 06:20:03PM -0800, Mario Smarduch wrote:
> Also with tick accounting enabled, and periodic timer HZ set to 1000 no irq time
> is reported. That's with running a ping flood - 1200 int/s, not sure why
> wouldn't any irq time be reported? The other two modes report irq time as expected.
> 
> On 11/18/2015 11:46 AM, Mario Smarduch wrote:
> > Hello,
> >   I noticed sched clock accounting can be enabled when arch-timer is
> > initialized. But arm64 doesn't appear to have 'HAVE_IRQ_TIME_ACCOUNTING'
> > selected (as of mainline 4.4-rc1) and IRQ_TIME_ACCOUNTING can't be selected.
> > After adding it to arch/arm64/Kconfig, option appears to work fine. Depending on
> > need all accounting options are fine, but irq time accounting appears to be most
> > preferable.
> > 
> > Any thoughts? Is it fine to enable it?
> > 
Is any of this related to KVM?

-Christoffer