[Bug 51123] HZ 250 causes choppy animation and slow performance

[Richard Gabriel]

Public bug reported:

Binary package hint: linux-source-2.6.15

The latest dapper kernel, 2.6.15-25-686, causes slowness and choppy
animation on my laptop.  linux-image-2.6.15-23-686 works normally and is
speedy.  I believe this has to do with the following change in the
changelog from 2.6.15-23 to 2.6.15-25.

* i386/amd64: Change HZ=1000 to HZ=250. The high frequency was causing
high power consumption on some laptops, and also some latency under
certain I/O loads.

I never noticed high power consumption on the -23 kernel.  Also, the new
-25 kernel runs without problems or slowness on my desktop.  It is just
my laptop that is noticeably slow and choppy.

Here is the CPU info on my laptop:
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.20GHz
stepping        : 8
cpu MHz         : 1197.096
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 nx est tm2
bogomips        : 2396.81

The model is a Panasonic CF-W4.

** Affects: linux-source-2.6.15 (Ubuntu)
     Importance: Untriaged
         Status: Unconfirmed

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HZ 250 causes choppy animation and slow performance
https://launchpad.net/bugs/51123