From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamie@jamieiles.com (Jamie Iles) Date: Fri, 12 Aug 2011 13:21:29 +0100 Subject: [PATCH v2] ARM: sched_clock: allow sched_clock to be selected at runtime In-Reply-To: <1313078531-25610-1-git-send-email-marc.zyngier@arm.com> References: <1313078531-25610-1-git-send-email-marc.zyngier@arm.com> Message-ID: <20110812122129.GA2643@pulham.picochip.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Aug 11, 2011 at 05:02:11PM +0100, Marc Zyngier wrote: > sched_clock() is yet another blocker on the road to the single > image. This patch implements an idea by Russell King: > > http://www.spinics.net/lists/linux-omap/msg49561.html > > Instead of asking the platform to implement both sched_clock() > itself and the rollover callback, simply register a read() > function, and let the ARM code care about sched_clock() itself, > the conversion to ns and the rollover. sched_clock() uses > this read() function as an indirection to the platform code. > > This allow some simplifications and possibly some footprint gain > when multiple platforms are compiled in. Among the drawbacks, > the removal of the *_fixed_sched_clock optimization which could > negatively impact some platforms (sa1100, tegra, versatile > and omap). > > Tested on 11MPCore, OMAP4 and Tegra. > > Cc: Imre Kaloz > Cc: Krzysztof Halasa > Cc: Tony Lindgren > Cc: Eric Miao > Cc: Colin Cross > Cc: Erik Gilling > Cc: Olof Johansson > Cc: Linus Walleij > Cc: Sascha Hauer > Cc: Alessandro Rubini > Cc: STEricsson > Cc: Lennert Buytenhek > Cc: Nicolas Pitre > Cc: Ben Dooks > Cc: Kukjin Kim > Cc: Jamie Iles Tested-by: Jamie Iles Jamie