From: Catalin Marinas Date: Fri, 27 Jul 2012 18:48:09 +0000 (-0400) Subject: time/jiffies: Allow CLOCK_TICK_RATE to be undefined X-Git-Tag: v3.6-rc2~37^2~4 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a7ea3bbf5d58f4df2265d312f91d5769eabc8144;p=pandora-kernel.git time/jiffies: Allow CLOCK_TICK_RATE to be undefined CLOCK_TICK_RATE is a legacy constant that defines the timer device's granularity. On hardware with particularly coarse granularity, this constant is used to reduce accumulated time error when using jiffies as a clocksource, by calculating the hardware's actual tick length rather then just assuming it is 1sec/HZ. However, for the most part this is unnecessary, as most modern systems don't use jiffies for their clocksource, and their tick device is sufficiently fine grained to avoid major error. Thus, this patch allows an architecture to not define CLOCK_TICK_RATE, in which case ACTHZ defaults to (HZ << 8). Signed-off-by: Catalin Marinas Acked-by: Arnd Bergmann Cc: Richard Cochran Cc: Prarit Bhargava Cc: Andrew Morton [ Commit log & intention tweaks ] Signed-off-by: John Stultz Link: http://lkml.kernel.org/r/1343414893-45779-2-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed