linux/arch/i386/kernel/timers
Mathieu Desnoyers dacb16b1a0 [PATCH] i386 and x86_64 TSC set_cyc2ns_scale imprecision
I just found out that some precision is unnecessarily lost in the
arch/i386/kernel/timers/timer_tsc.c:set_cyc2ns_scale function.  It uses a
cpu_mhz parameter when it could use a cpu_khz.  In the specific case of an
Intel P4 running at 3001.171 Mhz, the truncation to 3001 Mhz leads to an
imprecision of 19 microseconds per second : this is very sad for a timer with
nearly nanosecond accuracy.

Fix the x86_64 architecture too.

Cc: george anzinger <george@mvista.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:11 -08:00
..
common.c
Makefile
timer_cyclone.c [PATCH] x86: i8253/i8259A lock cleanup 2005-06-30 08:45:10 -07:00
timer_hpet.c [PATCH] i386 and x86_64 TSC set_cyc2ns_scale imprecision 2005-10-30 17:37:11 -08:00
timer_none.c
timer_pit.c [PATCH] useless includes of linux/irq.h in arch/i386 2005-09-26 18:29:50 -07:00
timer_pm.c [PATCH] add suspend/resume for timer 2005-09-05 00:06:18 -07:00
timer_tsc.c [PATCH] i386 and x86_64 TSC set_cyc2ns_scale imprecision 2005-10-30 17:37:11 -08:00
timer.c