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51fc97b935
linux/arch/x86/kernel
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Andi Kleen 51fc97b935 x86: allow TSC clock source on AMD Fam10h and some cleanup 
After a lot of discussions with AMD it turns out that TSC
on Fam10h CPUs is synchronized when the CONSTANT_TSC cpuid bit is set.
Or rather that if there are ever systems where that is not
true it would be their BIOS' task to disable the bit.

So finally use TSC gettimeofday on Fam10h by default.

Or rather it is always used now on CPUs where the AMD
specific CONSTANT_TSC bit is set.

This gives a nice speed bost for gettimeofday() on these systems
which tends to be by far the most common v/syscall.

On a Fam10h system here TSC gtod uses about 20% of the CPU time of
acpi_pm based gtod(). This was measured on 32bit, on 64bit
it is even better because TSC gtod() can use a vsyscall
and stay in ring 3, which acpi_pm doesn't.

The Intel check simply checks for CONSTANT_TSC too without hardcoding
Intel vendor. This is equivalent on 64bit because all 64bit capable Intel
CPUs will have CONSTANT_TSC set.

On Intel there is no CPU supplied CONSTANT_TSC bit currently,
but we synthesize one based on hardcoded knowledge which steppings
have p-state invariant TSC.

So the new logic is now: On CPUs which have the AMD specific
CONSTANT_TSC bit set or on Intel CPUs which are new enough
to be known to have p-state invariant TSC always use
TSC based gettimeofday()

Cc: lenb@kernel.org

Signed-off-by: Andi Kleen <ak@suse.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:32:40 +01:00
..
acpi x86: remove last users of FASTCALL 2008-01-30 13:31:16 +01:00
cpu x86: move X86_FEATURE_CONSTANT_TSC into early cpu feature detection 2008-01-30 13:32:40 +01:00
.gitignore .gitignore update for x86 arch 2007-10-17 21:19:04 +02:00
alternative.c x86: add set/clear_cpu_cap operations 2008-01-30 13:30:55 +01:00
aperture_64.c x86: clean up arch/x86/kernel/aperture_64.c printk()s 2008-01-30 13:30:10 +01:00
apic_32.c x86: clean up apic_32.c, take 2 2008-01-30 13:32:36 +01:00
apic_64.c x86: clean up apic_32/64.c 2008-01-30 13:32:35 +01:00
apm_32.c x86: get rid of checkpatch.pl complains on apm_32.c 2008-01-30 13:32:32 +01:00
asm-offsets_32.c x86: unify struct desc_ptr 2008-01-30 13:31:12 +01:00
asm-offsets_64.c x86: unify tss_struct 2008-01-30 13:31:31 +01:00
asm-offsets.c
audit_64.c
bootflag.c x86: coding style cleanup for kernel/bootflag.c 2008-01-30 13:32:31 +01:00
bugs_64.c
cpuid.c PM: Acquire device locks on suspend 2008-01-24 20:40:04 -08:00
crash_dump_32.c kmap leak fix for x86_32 kdump 2007-10-19 11:53:33 -07:00
crash_dump_64.c
crash.c x86: disable hpet legacy replacement for kdump 2007-12-03 17:17:10 +01:00
doublefault_32.c x86: unify tss_struct 2008-01-30 13:31:31 +01:00
ds.c x86, ptrace: support 32bit-cross-64bit BTS recording 2008-01-30 13:32:03 +01:00
e820_32.c x86 boot: use E820 memory map on EFI 32 platform 2008-01-30 13:31:19 +01:00
e820_64.c x86: prepare 64-bit architecture initialization for paravirt 2008-01-30 13:31:11 +01:00
early_printk.c [x86] remove uses of magic macros for boot_params access 2007-10-16 17:38:31 -07:00
early-quirks.c x86: clean up arch/x86/kernel/early-quirks.c 2008-01-30 13:31:26 +01:00
efi_32.c x86: 32-bit EFI runtime service support: fixes in sync with 64-bit support 2008-01-30 13:32:11 +01:00
efi_64.c x86: 32-bit EFI runtime service support: fixes in sync with 64-bit support 2008-01-30 13:32:11 +01:00
efi_stub_32.S
efi_stub_64.S x86: EFI runtime service support 2008-01-30 13:31:19 +01:00
efi.c x86: 32-bit EFI runtime service support: fixes in sync with 64-bit support 2008-01-30 13:32:11 +01:00
entry_32.S x86: move to .rodata/.init.data 2008-01-30 13:31:23 +01:00
entry_64.S x86: replace privileged instructions with paravirt macros 2008-01-30 13:32:08 +01:00
genapic_64.c x86: convert cpu_to_apicid to be a per cpu variable 2007-10-19 20:35:03 +02:00
genapic_flat_64.c x86: convert cpu_to_apicid to be a per cpu variable 2007-10-19 20:35:03 +02:00
geode_32.c
head64.c x86: do not set boot cpu in cpu_online_map at x86_64_start_kernel() 2008-01-30 13:30:46 +01:00
head_32.S fix lguest rmmod "bad pgd" 2008-01-01 11:30:35 -08:00
head_64.S x86: turn priviled operation into a macro in head_64.S 2008-01-30 13:31:10 +01:00
hpet.c x86: remove duplicate includes 2008-01-30 13:30:32 +01:00
i386_ksyms_32.c x86: unexport __{read,write}_lock_failed 2008-01-30 13:30:29 +01:00
i387.c x86: x86 user_regset cleanup 2008-01-30 13:31:55 +01:00
i8237.c Driver core: change sysdev classes to use dynamic kobject names 2008-01-24 20:40:40 -08:00
i8253.c mips, x86: optimize the i8259 code a bit 2008-01-30 13:30:47 +01:00
i8259_32.c x86: rename the struct pt_regs members for 32/64-bit consistency 2008-01-30 13:30:56 +01:00
i8259_64.c x86: move to .rodata/.init.data 2008-01-30 13:31:23 +01:00
init_task.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
io_apic_32.c arch/x86/kernel/io_apic_{64,32}.c: use time_before 2008-01-30 13:32:19 +01:00
io_apic_64.c arch/x86/kernel/io_apic_{64,32}.c: use time_before 2008-01-30 13:32:19 +01:00
io_delay.c x86: add DMI quirk for io-delay hangs on Compaq Presario V6000 laptops 2008-01-30 13:30:05 +01:00
ioport_32.c x86: rename the struct pt_regs members for 32/64-bit consistency 2008-01-30 13:30:56 +01:00
ioport_64.c x86: rename the struct pt_regs members for 32/64-bit consistency 2008-01-30 13:30:56 +01:00
irq_32.c x86: remove all definitions with fastcall 2008-01-30 13:31:17 +01:00
irq_64.c x86: rename the struct pt_regs members for 32/64-bit consistency 2008-01-30 13:30:56 +01:00
k8.c
kprobes.c x86: code clarification patch to Kprobes arch code 2008-01-30 13:32:32 +01:00
ldt.c x86: change write_ldt_entry signature 2008-01-30 13:31:13 +01:00
machine_kexec_32.c x86: unify struct desc_ptr 2008-01-30 13:31:12 +01:00
machine_kexec_64.c x86: 64-bit, make sparsemem vmemmap the only memory model 2008-01-30 13:30:47 +01:00
Makefile x86: unify arch/x86/kernel/Makefile(s) 2008-01-30 13:32:27 +01:00
mca_32.c
mfgpt_32.c x86: GEODE fix a race condition in the MFGPT timer tick 2008-01-22 23:30:16 +01:00
microcode.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
module_32.c
module_64.c
mpparse_32.c arch/x86/: spelling fixes 2008-01-30 13:31:42 +01:00
mpparse_64.c x86: acpi use cpu_physical_id 2007-10-19 20:35:03 +02:00
msr.c PM: Acquire device locks on suspend 2008-01-24 20:40:04 -08:00
nmi_32.c x86: clean up nmi_32/64.c 2008-01-30 13:30:33 +01:00
nmi_64.c x86: clean up nmi_32/64.c 2008-01-30 13:30:33 +01:00
numaq_32.c
paravirt_patch_32.c x86: move patching code to arch-specific file. 2008-01-30 13:32:10 +01:00
paravirt_patch_64.c x86: patching functions on 64-bit 2008-01-30 13:32:10 +01:00
paravirt.c replace x86_read/write_per_cpu with a common function. 2008-01-30 13:32:11 +01:00
pci-calgary_64.c x86: remove duplicate includes 2008-01-30 13:30:32 +01:00
pci-dma_32.c i386: Clean up duplicate includes in arch/i386/kernel/ 2007-10-17 20:15:51 +02:00
pci-dma_64.c x86: pci-dma_64.c: cleanups 2008-01-30 13:30:31 +01:00
pci-gart_64.c x86: code cleanups in arch/x86/kernel/pci-gart_64.c 2008-01-30 13:30:12 +01:00
pci-nommu_64.c x86 gart: rename iommu.h to gart.h 2007-10-30 00:22:22 +01:00
pci-swiotlb_64.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
pcspeaker.c
pmtimer_64.c x86: move pmtmr related declarations 2008-01-30 13:30:18 +01:00
process_32.c x86: x86 user_regset cleanup 2008-01-30 13:31:55 +01:00
process_64.c x86: x86 user_regset cleanup 2008-01-30 13:31:55 +01:00
ptrace.c x86, ptrace: add buffer size checks 2008-01-30 13:32:03 +01:00
quirks.c x86: Add HPET force support for MCP55 (nForce 5) chipsets 2007-10-23 22:37:25 +02:00
reboot_32.c x86: unify struct desc_ptr 2008-01-30 13:31:12 +01:00
reboot_64.c x86: EFI runtime service support: EFI runtime services 2008-01-30 13:31:19 +01:00
reboot_fixups_32.c x86: reboot fixup for wrap2c board 2007-11-17 16:27:02 +01:00
relocate_kernel_32.S
relocate_kernel_64.S
rtc.c x86: fix sched_clock() 2008-01-30 13:32:40 +01:00
scx200_32.c
setup64.c x86: unify tss_struct 2008-01-30 13:31:31 +01:00
setup_32.c x86: 32-bit EFI runtime service support: fixes in sync with 64-bit support 2008-01-30 13:32:11 +01:00
setup_64.c x86: move X86_FEATURE_CONSTANT_TSC into early cpu feature detection 2008-01-30 13:32:40 +01:00
sigframe_32.h
signal_32.c x86: remove all definitions with fastcall 2008-01-30 13:31:17 +01:00
signal_64.c x86: get rid of _MASK flags 2008-01-30 13:31:27 +01:00
smp_32.c x86: voluntary leave_mm before entering ACPI C3 2008-01-30 13:32:01 +01:00
smp_64.c x86: voluntary leave_mm before entering ACPI C3 2008-01-30 13:32:01 +01:00
smpboot_32.c x86: adjust enable_NMI_through_LVT0() 2008-01-30 13:31:24 +01:00
smpboot_64.c x86: provide 64-bit with a load_sp0 function. 2008-01-30 13:31:31 +01:00
smpcommon_32.c x86: change write_gdt_entry signature. 2008-01-30 13:31:13 +01:00
srat_32.c
stacktrace.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
step.c x86, ptrace: support for branch trace store(BTS) 2008-01-30 13:31:09 +01:00
summit_32.c spelling fixes: arch/i386/ 2007-10-20 01:13:56 +02:00
suspend_64.c x86: make __{save,restore}_processor_state static 2008-01-30 13:31:23 +01:00
suspend_asm_64.S x86: rename the struct pt_regs members for 32/64-bit consistency 2008-01-30 13:30:56 +01:00
sys_i386_32.c remove include/asm-*/ipc.h 2007-10-17 08:42:55 -07:00
sys_x86_64.c x86: PIE executable randomization, checkpatch fixes 2008-01-30 13:31:07 +01:00
syscall_64.c
syscall_table_32.S
tce_64.c x86: Create clflush() inline, remove hardcoded wbinvd 2007-10-17 20:16:12 +02:00
time_32.c x86: rename the struct pt_regs members for 32/64-bit consistency 2008-01-30 13:30:56 +01:00
time_64.c x86: remove get_cycles_sync 2008-01-30 13:32:39 +01:00
tls.c x86: x86 user_regset TLS 2008-01-30 13:31:52 +01:00
tls.h x86: x86 user_regset TLS 2008-01-30 13:31:52 +01:00
topology.c x86: arch_register_cpu() section fix 2007-12-04 17:19:07 +01:00
trampoline_32.S x86: misc. constifications 2007-10-17 20:16:08 +02:00
trampoline_64.S x86: misc. constifications 2007-10-17 20:16:08 +02:00
traps_32.c x86: remove all definitions with fastcall 2008-01-30 13:31:17 +01:00
traps_64.c x86: get rid of _MASK flags 2008-01-30 13:31:27 +01:00
tsc_32.c x86: allow TSC clock source on AMD Fam10h and some cleanup 2008-01-30 13:32:40 +01:00
tsc_64.c x86: allow TSC clock source on AMD Fam10h and some cleanup 2008-01-30 13:32:40 +01:00
tsc_sync.c x86: remove get_cycles_sync 2008-01-30 13:32:39 +01:00
verify_cpu_64.S
vm86_32.c arch/x86/: spelling fixes 2008-01-30 13:31:42 +01:00
vmi_32.c x86: change write_ldt_entry signature 2008-01-30 13:31:13 +01:00
vmiclock_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
vmlinux_32.lds.S x86: vmlinux_32.lds.S: remove repeated comment from the x86-32 linker script 2008-01-30 13:30:46 +01:00
vmlinux_64.lds.S all archs: consolidate init and exit sections in vmlinux.lds.h 2008-01-28 23:21:17 +01:00
vmlinux.lds.S
vsmp_64.c x86: clean up arch/x86/kernel/vsmp_64.c 2008-01-30 13:30:24 +01:00
vsyscall_64.c x86: map vsyscalls early enough 2008-01-30 13:32:39 +01:00
x8664_ksyms_64.c x86: export cpu_gdt_descr 2008-01-30 13:31:10 +01:00