Date: Thu, 24 Nov 2011 10:00:52 +0200 From: Oles Hnatkevych <don_oles@able.com.ua> To: freebsd-questions@freebsd.org Subject: 8.2 broken CPU speed detection on IBM server Message-ID: <4ECDF9B4.6080409@able.com.ua>
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Hello!
We've got very strange problem with (at least) two identical IBM Servers
System Information
Manufacturer: IBM
Product Name: IBM System x3650 -[79792AG]-
FreeBSD 8.2-RELEASE is installed.
Depending on the phase of the moon when kernel boots with a change close
to 70% the CPU speed is wrongly detected, affecting timing operation for
the system.
This looks this way:
FreeBSD 8.2-RELEASE #0: Thu Sep 22 13:43:28 EEST 2011
root@newgate.metro.kiev.ua:/usr/obj/usr/src/sys/NEWGATE i386
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Xeon(R) CPU 5110 @ 1.60GHz (10748.77-MHz
686-class CPU)
Origin = "GenuineIntel" Id = 0x6fb Family = 6 Model = f Stepping = 11
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
Features2=0x4e33d<SSE3,DTES64,MON,DS_CPL,VMX,TM2,SSSE3,CX16,xTPR,PDCM,DCA>
AMD Features=0x20100000<NX,LM>
AMD Features2=0x1<LAHF>
TSC: P-state invariant
10.748 Ghz!!!
As a result we see 296 interrupts per seconds on CPU (six times less)
# vmstat -i
interrupt total rate
irq15: ata1 35 0
irq17: aac0 525059 22
irq23: uhci0 uhci2+ 37899 1
cpu0: timer 7063047 296
irq256: bce0 5275133 221
irq257: bce1 43824849 1842
cpu3: timer 7063046 296
cpu2: timer 7063043 296
cpu1: timer 7063045 296
Total 77915156 3275
After that ping, top and other applications depending on timer slow down
six times (i.e. pings once in 6 seconds).
And to round this up:
# time sleep 1
real 0m6.737s
user 0m0.000s
sys 0m0.000s
Playing with BIOS settings did not help at all. Even pressing 'restore
defaults'. Updating BIOS did not help either. On the live system kernel
has been recompiled, but that does not matter since on another test box
the generic kernel is affected by the same problem.
What to do???? Try 7-CURRENT? Install Linux? ;)
--
----------
Oles Hnatkevych
Skype: don_oles
http://gnut.able.com.ua/
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