using chatr

[azita asefi]

I am trying to increase the virtual page size
for the WebSphere java process that I am running by the following command(we are using HP 11.11):

chatr +pi64M +pd64M /opt/WebSphere/AppServer/java/bin/PA_RISC2.0/native_threads/java

but i am getting the following error:

chatr(warning): dl_header_ext.size != sizeof(dl_header_ext). Please update your version of the linker.

/opt/WebSphere/AppServer/java/bin/PA_RISC2.0/native_threads/java:
current values:
normal executable
shared library dynamic path search:
SHLIB_PATH enabled first
embedded path disabled second Not Defined
shared library list:
dynamic /usr/lib/libpthread.1
dynamic ../../../../build/HP_UX/lib/PA_RISC2.0/server/libjvm.sl
dynamic /usr/lib/libdld.2
dynamic /usr/lib/libc.2
shared library binding:
deferred
global hash table disabled
plabel caching disabled
global hash array size:1103
global hash array nbuckets:3
shared vtable support disabled
static branch prediction disabled
executable from stack: D (default)
kernel assisted branch prediction enabled
lazy swap allocation disabled
text segment locking disabled
data segment locking disabled
third quadrant private data space disabled
fourth quadrant private data space disabled
third quadrant global data space disabled
data page size: 4M
instruction page size: 4M
nulptr references enabled
shared library private mapping disabled
shared library text merging disabled
chatr(error): cannot open file for writing /opt/WebSphere/AppServer/java/bin/PA_RISC2.0/native_threads/java

[Alex Glennie]

First one's a warning that can be ignored, PHSS_26560 may help ld/linker tools patch, as to the second was the WebSphere java process running at the time .... I'm thinking you may have tried to use chatr on a running executable ?

[Mike Stroyan]

The "chatr(error): cannot open file for writing /opt/WebSphere/AppServer/java/bin/PA_RISC2.0/native_threads/java"
message could be caused by having the process running using the file. It could just be a matter of needing to use chmod to add write permission before you use chatr.
The chatr +pd may have less effect than you would expect. JVMs typically allocate the java heap using mmap instead of mallocs. The +pd setting only affects the malloc/sbrk memory. The WebSphere jvm may be using explicit madvise calls to set the page size for mmap regions.