From: Peter Zijlstra <peterz@infradead.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Venkatesh Pallipadi <venki@google.com>
Subject: Re: [PATCH 0/4] cputime: Virtual cputime accounting small cleanups and consolidation
Date: Thu, 21 Jun 2012 10:53:21 +0200 [thread overview]
Message-ID: <1340268801.21745.162.camel@twins> (raw)
In-Reply-To: <1340267442.21745.156.camel@twins>
On Thu, 2012-06-21 at 10:30 +0200, Peter Zijlstra wrote:
> On Thu, 2012-06-21 at 02:46 +0200, Frederic Weisbecker wrote:
> > > So I understand why s390,ia64 want the sched hook, but I don't see why
> > > ppc would need it, their account_process_tick() can fold whatever they
> > > need on the tick.
> >
> > I think in any case you need to flush the time on a descheduling task otherwise
> > its pending time will be accounted later to the next task when it
> > receives an irq.
> >
> > So I fear we still need that sched switch hook even with per cpu data. This
> > may be a simple account_system_vtime() call.
>
> Did I miss a per-task something in there?
Gah yeah.. I was staring too hard at the arch code and missed the task
accounting in the core code.
OK, so that switch hook stays :-)
next prev parent reply other threads:[~2012-06-21 8:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 13:43 [PATCH 0/4] cputime: Virtual cputime accounting small cleanups and consolidation Frederic Weisbecker
2012-06-19 13:43 ` [PATCH 1/4] cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING Frederic Weisbecker
2012-06-19 13:43 ` [PATCH 2/4] sched: Move cputime code to its own file Frederic Weisbecker
2012-06-19 13:43 ` [PATCH 3/4] cputime: Consolidate vtime handling on context switch Frederic Weisbecker
2012-06-19 13:43 ` [PATCH 4/4] s390: Remove leftover account_tick_vtime() header Frederic Weisbecker
2012-06-19 18:55 ` [PATCH 0/4] cputime: Virtual cputime accounting small cleanups and consolidation Luck, Tony
2012-06-20 22:26 ` Peter Zijlstra
2012-06-21 0:46 ` Frederic Weisbecker
2012-06-21 7:58 ` Martin Schwidefsky
2012-06-21 12:04 ` Peter Zijlstra
2012-06-21 16:37 ` Frederic Weisbecker
2012-06-21 8:30 ` Peter Zijlstra
2012-06-21 8:53 ` Peter Zijlstra [this message]
2012-07-09 17:50 ` Frederic Weisbecker
2012-07-09 21:03 ` Benjamin Herrenschmidt
2012-08-03 11:12 ` Frederic Weisbecker
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