Re: [RFC PATCH 24/30] cputime: Increment kcpustat directly on irqtime account

From: Martin Schwidefsky
Date: Mon Dec 01 2014 - 09:41:40 EST

On Fri, 28 Nov 2014 19:23:54 +0100
Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote:

> The irqtime is accounted is nsecs and stored in
> cpu_irq_time.hardirq_time and cpu_irq_time.softirq_time. Once the
> accumulated amount reaches a new jiffy, this one gets accounted to the
> kcpustat.
> This was necessary when kcpustat was stored in cputime_t, which could at
> worst have a jiffies granularity. But now kcpustat is stored in nsecs
> so this whole discretization game with temporary irqtime storage has
> become unnecessary.
> We can now directly account the irqtime to the kcpustat.

Isn't the issue here that two different approaches to cputime accounting
get mixed here? On the one hand a cputime_t based on jiffies and on the
other CONFIG_IRQ_TIME_ACCOUNTING which uses sched_clock_cpu() to create
the accounting deltas.

blue skies,

"Reality continues to ruin my life." - Calvin.

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