Re: [1/3] Bugfix: Don't use the TSC in sched_clock if unstable

["Guillaume Chazarain" <guichaz@gmail.com>]

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2007/3/4, Andi Kleen <ak@suse.de>:

> On what hardware?

Pentium M 798 MHz -> 2GHz

> And how many frequency transitions do you have per second?

10 in a kernel compile exhibiting audio skips.

Anyway, the "Clocksource tsc unstable (delta = -263211549 ns)" line
in the dmesg I attached to the previous mail confirms IMHO that my
TSC is too unstable for scheduling purpose.

15 minutes after booting, including a kernel compile halted on the
first audio skip, I have this in
/sys/devices/system/cpu/cpu0/cpufreq/stats/trans_table

   From  :    To
         :   1995000   1596000   1330000   1064000    798000
  1995000:         0        67       101       128       367
  1596000:        20         0         3         3        41
  1330000:        21         0         0        10        73
  1064000:        30         0         0         0       111
   798000:       592         0         0         0         0

Nothing alarming I presume.

Thanks.

-- 
Guillaume

[-- Attachment #2: cpuinfo --]
[-- Type: application/octet-stream, Size: 451 bytes --]

processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 13
model name	: Intel(R) Pentium(R) M processor 2.00GHz
stepping	: 8
cpu MHz		: 798.000
cache size	: 2048 KB
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 2
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe est tm2
bogomips	: 1596.62
clflush size	: 64