From mboxrd@z Thu Jan 1 00:00:00 1970 From: leif.lindholm@arm.com (Leif Lindholm) Date: Fri, 29 Jan 2010 15:17:59 -0000 Subject: ARM11 MPCore: Adding nop to __delay() doubles the BogoMIPS/lpj In-Reply-To: <20100129145425.GC27577@pengutronix.de> References: <20100129145425.GC27577@pengutronix.de> Message-ID: <000101caa0f6$3dfadc50$b9f094f0$@lindholm@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > -----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