linux/arch/x86
Thomas Gleixner a977c40095 x86: TSC make the calibration loop smarter
The last changes made the calibration loop 250ms long which is far
too much. Try to do that more clever.

Experiments have shown that using a 10ms delay for the PIT based calibration
gives us a good enough value. If we have a reference (HPET/PMTIMER) and the
result of the PIT and the reference is close enough, then we can break out of
the calibration loop on a match right away and use the reference value.

Otherwise we just loop 3 times and decide then, which value to take.

One caveat is that for virtualized environments the PIT calibration often does
not work at all and I found out that 10us is a bit too short as well for the
reference to give a sane result. The solution here is to make the last loop
longer when the first two PIT calibrations failed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-04 17:35:35 +02:00
..
boot x86: fix build warnings in real mode code 2008-08-18 09:20:14 +02:00
configs x86: update defconfigs 2008-08-27 08:14:17 +02:00
crypto [CRYPTO] aes-x86-32: Remove unused return code 2008-04-21 10:19:21 +08:00
ia32 tracehook: exec 2008-07-26 12:00:08 -07:00
kernel x86: TSC make the calibration loop smarter 2008-09-04 17:35:35 +02:00
kvm KVM: MMU: Fix torn shadow pte 2008-08-25 17:24:27 +03:00
lguest lguest: set max_pfn_mapped, growl loudly at Yinghai Lu 2008-07-29 09:58:31 +10:00
lib x86: msr: propagate errors from smp_call_function_single() 2008-08-25 17:45:48 -07:00
mach-default x86: add ->pre_time_init to x86_quirks 2008-07-20 09:25:52 +02:00
mach-es7000 x86: move the last Dprintk instance to pr_debug() 2008-07-21 21:58:34 +02:00
mach-generic x86: make generic arch support NUMAQ, fix 2008-07-08 10:35:45 +02:00
mach-rdc321x removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
mach-voyager Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
math-emu x86: coding style fixes to arch/x86/math-emu/reg_constant 2008-06-18 15:00:13 +02:00
mm x86: fix two modpost warnings in mm/init_64.c 2008-08-22 07:51:54 +02:00
oprofile x86: fix oprofile + hibernation badness 2008-08-20 16:18:31 +02:00
pci Un-break printk strings in x86 PCI probing code 2008-09-02 10:38:28 -07:00
power x86: fix i486 suspend to disk CR4 oops 2008-08-18 08:50:19 +02:00
vdso Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus 2008-07-21 16:37:17 +02:00
video x86: video/fbdev.c: add MODULE_LICENSE 2008-05-04 20:04:46 +02:00
xen xen: don't use sysret for sysexit32 2008-07-24 12:28:12 +02:00
Kconfig [x86] Clean up MAXSMP Kconfig, and limit NR_CPUS to 512 2008-08-25 14:15:38 -07:00
Kconfig.cpu x86: fix crash due to missing debugctlmsr on AMD K6-3 2008-07-22 14:16:37 +02:00
Kconfig.debug x86: Fix help message for STRICT_DEVMEM config option 2008-07-21 13:04:08 -07:00
Makefile x86, RDC321x: add to mach-default 2008-07-26 13:51:46 +02:00
Makefile_32.cpu