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Russell King edc4d27255 ARM: sched_clock: make minsec argument to clocks_calc_mult_shift() zero
The purpose of the minsec argument is to prevent 64-bit math overflow
when the number of cycles is multiplied up.  However, the multipler
is 32-bit, and in the sched_clock() case, the cycle counter is up to
32-bit as well.  So the math can never overflow.

With a value of 60, and clock rates greater than 71MHz, the calculated
multiplier is unnecessarily reduced in value, which reduces accuracy by
maybe 70ppt.  It's almost not worth bothering with as the oscillator
driving the counter won't be any more than 1ppm - unless you're using
a rubidium lamp or caesium fountain frequency standard.

So, set the minsec argument to zero.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-11 16:44:02 +00:00
..
alpha perf: Dynamic pmu types 2010-12-16 11:36:43 +01:00
arm ARM: sched_clock: make minsec argument to clocks_calc_mult_shift() zero 2011-01-11 16:44:02 +00:00
avr32 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
blackfin BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
cris Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
frv BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
h8300 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
ia64 SCSI host lock push-down 2010-11-16 13:33:23 -08:00
m32r Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
m68k BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
m68knommu BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
microblaze Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
mips Merge commit 'v2.6.37-rc7' into perf/core 2010-12-22 11:53:23 +01:00
mn10300 arch/mn10300/kernel/irq.c: fix build 2011-01-03 16:36:33 -08:00
parisc parisc: convert the rest of the irq handlers to simple/percpu 2010-12-04 11:15:19 -05:00
powerpc Merge commit 'v2.6.37-rc8' into perf/core 2011-01-04 08:08:54 +01:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2011-01-06 12:30:19 -08:00
score Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
sh Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm 2011-01-06 16:50:35 -08:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6 2011-01-06 15:30:54 -08:00
tile arch/tile: handle rt_sigreturn() more cleanly 2010-12-17 16:59:29 -05:00
um uml: disable winch irq before freeing handler data 2010-11-25 06:50:39 +09:00
x86 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 11:12:17 -08:00
xtensa Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
.gitignore
Kconfig mutexes, sched: Introduce arch_mutex_cpu_relax() 2010-11-26 15:05:34 +01:00