From: Ralf Baechle <ralf@linux-mips.org>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: David Daney <ddaney@caviumnetworks.com>, linux-mips@linux-mips.org
Subject: Re: [PATCH] MIPS: Make collection of FPU emulator statistics optional.
Date: Tue, 3 Nov 2009 11:21:12 +0100 [thread overview]
Message-ID: <20091103102112.GA24619@linux-mips.org> (raw)
In-Reply-To: <20091103093743.GA23235@linux-mips.org>
On Tue, Nov 03, 2009 at 10:37:43AM +0100, Ralf Baechle wrote:
> > On Mon, Nov 02, 2009 at 04:12:35PM -0800, David Daney wrote:
> > > On SMP systems, the collection of statistics can cause cache line
> > > bouncing in the lines associated with the counters. Make the
> > > statistics configurable so this can be avoided. Also we need to make
> > > the counters atomic_t so that they can be reliably modified on SMP
> > > systems.
> >
> > how about making it a per_cpu thing and avoid the atomic instructions ?
>
> Working on that. The tricky part is that statistics may end up somewhat
> inaccurate when a reader iterates over the per-CPU array of stats to add
> them all up. I've not found a solution for that yet but then again it
> should not be something which actually would cause pain.
Or more useful than a global statistics would be per process stats.
How should a useful interface look like?
Ralf
prev parent reply other threads:[~2009-11-03 10:19 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-03 0:12 [PATCH] MIPS: Make collection of FPU emulator statistics optional David Daney
[not found] ` <20091103093024.GA6425@alpha.franken.de>
2009-11-03 9:37 ` Ralf Baechle
2009-11-03 10:21 ` Ralf Baechle [this message]
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