On 3/21/2015 11:52 AM, John Baldwin wrote:
http://tancsa.com/time/
Do you know why you are using the HPET instead of TSC for timestamping?
Hi,
I am not consciously making any time keep decisions.
kern.eventtimer.choice: HPET(550) HPET1(450) LAPIC(400) i8254(100) RTC(0)
kern.timecounter.choice: TSC(800) HPET(950) ACPI-fast(900) i8254(0)
dummy(-1000000)
(The full hardware info is at the above url)
Using the TSC can make a non-trivial performance difference since userland
can calculate timestamps without using system calls when it is used.
(That is not related to this case, but switching to the TSC in general is
preferable.)
There are a few generations of Intel CPUs where you can't mix deeper sleep
states with the TSC as timecounter, but those CPUs are getting to be a bit
older at this point.
This one is an AMD
CPU: AMD G-T40E Processor (1000.02-MHz K8-class CPU)
Origin="AuthenticAMD" Id=0x500f20 Family=0x14 Model=0x2 Stepping=0
Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
Features2=0x802209<SSE3,MON,SSSE3,CX16,POPCNT>
AMD Features=0x2e500800<SYSCALL,NX,MMX+,FFXSR,Page1GB,RDTSCP,LM>
AMD
Features2=0x35ff<LAHF,CMP,SVM,ExtAPIC,CR8,ABM,SSE4A,MAS,Prefetch,IBS,SKINIT,WDT>
SVM: NP,NRIP,NAsids=8
TSC: P-state invariant, performance statistics
real memory = 2115297280 (2017 MB)
avail memory = 2018639872 (1925 MB)
Event timer "LAPIC" quality 400
ACPI APIC Table: <CORE COREBOOT>
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
FreeBSD/SMP: 1 package(s) x 2 core(s)
cpu0 (BSP): APIC ID: 0
cpu1 (AP): APIC ID: 1
ioapic0 <Version 2.1> irqs 0-23 on motherboard
random: <Software, Yarrow> initialized
module_register_init: MOD_LOAD (vesa, 0xffffffff80d9ddf0, 0) error 19
kbd0 at kbdmux0
acpi0: <CORE COREBOOT> on motherboard
acpi0: Power Button (fixed)
cpu0: <ACPI CPU> on acpi0
cpu1: <ACPI CPU> on acpi0
--
-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, m...@sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada http://www.tancsa.com/
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