From: leif.lindholm@arm.com (Leif Lindholm)
To: linux-arm-kernel@lists.infradead.org
Subject: ARM11 MPCore: Adding nop to __delay() doubles the BogoMIPS/lpj
Date: Fri, 29 Jan 2010 15:17:59 -0000 [thread overview]
Message-ID: <000101caa0f6$3dfadc50$b9f094f0$@lindholm@arm.com> (raw)
In-Reply-To: <20100129145425.GC27577@pengutronix.de>
> -----Original Message-----
> From: Uwe Kleine-K?nig [mailto:u.kleine-koenig at pengutronix.de]
> Sent: 29 January 2010 14:54
> > But as Catalin says, this makes no functional difference, even though
> > it might look "more impressive" :)
>
> With a bigger number of loops_per_seconds the maximal period that can
> be delayed for is shorter and the granularity is better, no?
I concur that this aspect of my comment was technically incorrect - but if
your code was depending on either of those, surely that would be a problem
in itself?
The minimum time would be questionable anyway, as loops_per_second is an
average, and the branch predictor is fairly likely to miss on the first time
through the loop unless your code uses a lot of delays.
/
Leif
next prev parent reply other threads:[~2010-01-29 15:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-29 14:54 ARM11 MPCore: Adding nop to __delay() doubles the BogoMIPS/lpj Uwe Kleine-König
2010-01-29 15:17 ` Leif Lindholm [this message]
2010-01-29 15:26 ` Russell King - ARM Linux
-- strict thread matches above, loose matches on Subject: below --
2010-01-27 16:45 Dirk Behme
2010-01-28 13:03 ` Catalin Marinas
2010-01-29 5:08 ` Shilimkar, Santosh
2010-01-29 12:17 ` Leif Lindholm
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