JDK-4949482 : CMS: -XX:NewSize, MaxNewSize CL arguments sometimes ignored
  • Type: Bug
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 1.4.2_02
  • Priority: P2
  • Status: Resolved
  • Resolution: Fixed
  • OS: linux
  • CPU: x86
  • Submitted: 2003-11-05
  • Updated: 2009-06-25
  • Resolved: 2004-01-15
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Unresolved : Release in which this issue/RFE will be addressed.
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Other
1.4.2_04 04Fixed
Description
On a multi-cpu server, the following JVM parameters 

  -XX:NewSize=8m
  -XX:MaxNewSize=8m

are ignored ( when set them below 16m). So when you set them to 8,
verbose gc indicates 16.  If you set it to 32m, it indicates 32m.
However, if hyperthreading is off the 16m minimum limitation is removed.



Platform Details
-------------------

JVM 1.4.2_02
Linux: 

RedHat AS 3.0 (we see the same behavior with RedHat AS 2.1).
Hyperthreading turned on (the machine behaves has a 4 CPUs when it
really has only 2). 

Linux version 2.4.21-4.ELsmp (###@###.###) (gcc version
3.2.3 20030502 (Red Hat Linux 3.2.3-20)) 


Hardware:
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 15
model		: 2
model name	: Intel(R) Xeon(TM) CPU 2.80GHz
stepping	: 7
cpu MHz		: 2790.820
cache size	: 512 KB
physical id	: 0
siblings	: 2
runqueue	: 0
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 pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
bogomips	: 5570.56

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 15
model		: 2
model name	: Intel(R) Xeon(TM) CPU 2.80GHz
stepping	: 7
cpu MHz		: 2790.820
cache size	: 512 KB
physical id	: 3
siblings	: 2
runqueue	: 1
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 pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
bogomips	: 5570.56

processor	: 2
vendor_id	: GenuineIntel
cpu family	: 15
model		: 2
model name	: Intel(R) Xeon(TM) CPU 2.80GHz
stepping	: 7
cpu MHz		: 2790.820
cache size	: 512 KB
physical id	: 0
siblings	: 2
runqueue	: 0
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 pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
bogomips	: 5570.56

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 15
model		: 2
model name	: Intel(R) Xeon(TM) CPU 2.80GHz
stepping	: 7
cpu MHz		: 2790.820
cache size	: 512 KB
physical id	: 3
siblings	: 2
runqueue	: 1
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 pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
bogomips	: 5570.56


@@@@@@@@@@@@@@@@@@@@@@@@@ working example @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
From: Srinivas 
Subject: Re: verbose flags for more information on state of CMS heap etc.


Hi Keith --


I just tried it on a local linux box and it works fine (i ask for 8M new
size, i get 8 M new size).

Here's what i am running:

Linux perf-lx3 2.4.21-1.1931.2.399.entsmp #1 SMP Wed Aug 20 15:51:09 EDT 
2003 i686 i686 i386 GNU/Linux

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 11
model name      : Intel(R) Pentium(R) III CPU family      1400MHz
stepping        : 1
cpu MHz         : 1396.496
cache size      : 512 KB
physical id     : 0
siblings        : 1
runqueue        : 0
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 pse36 mmx fxsr sse
bogomips        : 2785.28

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 11
model name      : Intel(R) Pentium(R) III CPU family      1400MHz
stepping        : 1
cpu MHz         : 1396.496
cache size      : 512 KB
physical id     : 0
siblings        : 1
runqueue        : 1
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 pse36 mmx fxsr sse
bogomips        : 2791.83

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


Comments
CONVERTED DATA BugTraq+ Release Management Values COMMIT TO FIX: 1.4.2_04 generic FIXED IN: 1.4.2_04 INTEGRATED IN: 1.4.2_04
14-06-2004

EVALUATION see comments section.
11-06-2004

WORK AROUND No workaround excep to live with what the VM gives you. This is a serious problem for tuning heaps for optimal performance.
11-06-2004

SUGGESTED FIX see file:///net/spot.sfbay/archive02/ysr/nortel/webrev/index.html.
11-06-2004

PUBLIC COMMENTS ...
10-06-2004