Date: Fri, 30 Aug 2013 19:17:07 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Waiman Long <Waiman.Long@hp.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Jeff Layton <jlayton@redhat.com>, Miklos Szeredi <mszeredi@suse.cz>,
        Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>, Andi Kleen <andi@firstfloor.org>,
        "Chandramouleeswaran, Aswin" <aswin@hp.com>,
        "Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH v7 1/4] spinlock: A new lockref structure for lockless
 update of refcount
Message-ID: <20130830171707.GV31370@twins.programming.kicks-ass.net>
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On Thu, Aug 29, 2013 at 09:43:07AM -0700, Linus Torvalds wrote:

> We'll see. The real problem is that I'm not sure if I can even see the
> scalability issue on any machine I actually personally want to use
> (read: silent). On my current  system I can only get up to 15%
> _raw_spin_lock by just stat'ing the same file over and over and over
> again from lots of threads.

Yeah, silent basically limits you to i7 single socket systems and sadly
Intel doesn't seem to want to make those with more than 4 cores on :/

I've got a i7-K part (SNB iirc) with a _huge_ scythe cooler and a high
efficiency fanless PSU for a system that's near noiseless -- as in my
Thinkpad actually makes more noise.
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