Re: [PATCH 0/4] Finer granularity and task/cgroup irq time accounting

From: Peter Zijlstra <peterz@infradead.org>
To: balbir@linux.vnet.ibm.com
Cc: Venkatesh Pallipadi <venki@google.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Paul Menage <menage@google.com>,
	linux-kernel@vger.kernel.org, Paul Turner <pjt@google.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Paul Mackerras <paulus@samba.org>,
	Tony Luck <tony.luck@intel.com>
Subject: Re: [PATCH 0/4] Finer granularity and task/cgroup irq time accounting
Date: Tue, 24 Aug 2010 15:08:14 +0200	[thread overview]
Message-ID: <1282655294.2605.2716.camel@laptop> (raw)
In-Reply-To: <20100824124726.GQ4684@balbir.in.ibm.com>

On Tue, 2010-08-24 at 18:17 +0530, Balbir Singh wrote:
> 
> "There are usecases where reporting this time against task
> or task groups or cgroups will be useful for user/administrator
> in terms of resource planning and utilization charging"

Or confusing, what happens if you attribute the IRQ overhead of a
ping-flood to your tasks?

By not providing these numbers per task/group people will have to
actually think about what it is that is causing these high irq loads and
have a chance of actually doing better than random attribution.

So no, providing random numbers on the slight chance that they might
possibly make sense for your workload doesn't seem like a sound reason
to provide them.