Date: Tue, 11 Feb 2014 00:03:30 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Jason Low <jason.low2@hp.com>,
        Waiman Long <waiman.long@hp.com>, mingo@kernel.org,
        paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org,
        tglx@linutronix.de, riel@redhat.com, davidlohr@hp.com, hpa@zytor.com,
        andi@firstfloor.org, aswin@hp.com, scott.norton@hp.com,
        chegu_vinod@hp.com
Subject: Re: [PATCH 0/8] locking/core patches
Message-Id: <20140211000330.d791513d.akpm@linux-foundation.org>
In-Reply-To: <20140211071700.GH27965@twins.programming.kicks-ass.net>
References: <20140210195820.834693028@infradead.org>
	<20140210150230.b7f46688093ebc5c45fee870@linux-foundation.org>
	<20140211071700.GH27965@twins.programming.kicks-ass.net>
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On Tue, 11 Feb 2014 08:17:00 +0100 Peter Zijlstra <peterz@infradead.org> wrote:

> On Mon, Feb 10, 2014 at 03:02:30PM -0800, Andrew Morton wrote:
> > On Mon, 10 Feb 2014 20:58:20 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> > 
> > > Hi all,
> > > 
> > > I would propose merging the following patches...
> > > 
> > > The first set is mostly from Jason and tweaks the mutex adaptive
> > > spinning, AIM7 throughput numbers:
> > > 
> 
>                          Jobs/min/ Jobs/sec/ Time:   Time:  Time:   Time:           Running child time
>          Forks  Jobs/min   child    child parent  childU childS  std_dev   JTI   :max  :min
> 
> > > PRE:  100   2000.04  21564.90 2721.29 311.99     3.12       0.01     0.00     99
> > > POST: 100   2000.04  42603.85 5142.80 311.99     3.12       0.00     0.00     99
> > 
> > What do these columns represent?  I'm guessing the large improvement
> > was in context switches?
> 
> I pasted the header from reaim above;

hmpf.  I wonder what's the difference between Jobs/min, Jobs/min(child)
and Jobs/sec(child), which is not Jobs/min(child) / 60.

> I'm not entirely sure what the
> bloody thing does and I hate that it takes hours to get these numbers :/
>
> Bloody stupid benchmark if you ask me.

heh, yes, it's stupid how long many benchmarks take.  Ditch it.  A
change like this should be testable with a 30-line microbenchmark which
runs in 5 seconds tops.
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