Hi,
I have HP-UX 11i v3 running on ia64. One of my application is 32-bit and I want to increase the memory allocation of this file upto 2GB. I am contentiously receiving an error message of Out of Memory.
Can you please explain the procedure what kernel configuration( like maxdsize or maxdsize_64) i need to set and also do i need to set anything on the application binary ?
Thanks in advance.
My file chatr is as follows
Last edited by jim mcnamara; 08-30-2012 at 02:49 PM..
Hi folks,
We are using following listed configurations for a particular application.
HP-UX 11i
Sun Java 2 SDK Standard Edition 1.4.1 (version shipped with WebLogic 8)
Oracle 9i Release 2 (Oracle 9.2.0)
BEA WebLogic Server 8.1 SP3
It seems a memory leak when we use above configurations.... (1 Reply)
Hellp all,
if there is 3G memory in my Unix server I want to know if all the 3G space can be used by ong sigle process. As i know, in Windows, one process can only access at most 1G memory despite there is probably more than 1G memory is equipped. (1 Reply)
Hi all,
I have a HP-UX Server with 4 gigabytes of physical RAM. When I use the 'Glance' utility to see what my memory utilization is, my memory usage shows up maxed out at 99%. I shut off all the known processes that I'm running on that box and the memory utilization is still at 78% (with Swap... (1 Reply)
How can i Globally set the maximum core memory a single process can take. IE, i want to set that no single process may get more than 11GB.
I am running red hat enterprise unix 4. (9 Replies)
Hi everyone,
I'm not new to C programming, but I'm having question regarding the memory allocation of a pointer variable which, for instance, will be declared in main(), but its memory will be allocated in subroutine.
To clearify my question, I provide a small working example:
#include... (1 Reply)
Hi Experts
I need some help in static memory allocation in C. I have a program in which I declared 2 variables, one char array and one integer. I was little surprised to see the addresses of the variables.
First:
int x;
char a;
printf("%u %u\n', &x, a);
I got the addresses displayed... (2 Replies)
Hello Guys
I have a small confusion in the dynamic memory allocation concept.
If we declare a pointer say a char pointer, we need to allocate adequate memory space.
char* str = (char*)malloc(20*sizeof(char));
str = "This is a string";
But this will also work.
char* str = "This... (2 Replies)
When we dynamically allocate the memory say 100 integers say
int *x = new int(1000);
then does entire chunk of memory gets allocated at once after the completion of the statement?
I mean will the the concept of page fault come into picture over here? (3 Replies)
I want to run a C program on my linux machine. I want to allocate specific heap size for that process (C program) to run.
How can I do that?
I know in Java same can be done using -Xmx option.
There may be some option which I can specify in the C program like Java or may be in linux process. (8 Replies)
Discussion started by: Ankur Goyal
8 Replies
LEARN ABOUT HPUX
copy_on_write
copy_on_write(5) File Formats Manual copy_on_write(5)NAME
copy_on_write - dynamically enable or disable copy-on-write semantics for privately mapped files, private segments of child process after
fork(), and private segments locked by mlock()
VALUES
Failsafe
Default
Allowed values
or
DESCRIPTION
This tunable dynamically enables or disables the copy-on-write behavior in private and system calls. When the tunable is disabled, copy-
on-access behavior is followed; this is the legacy behavior (HP-UX 11i v3 and previous releases) where private segments are copied upon
access. Disabling this tunable will preserve that old behavior.
Following is a summary of what happens when the tunable is enabled:
o For a process' private data (data segment, stack, heap, RSE) is copied only when the child process writes for the first time.
o For if mapping is created for a file for which exists, a separate copy of the page is created for only when it first writes to
the page. As long as reads, it shares the page with mapping. That is, updates made by shared mapping will be visible to private
mapping until private mapping writes.
o For locking privately mapped segments does not result in copying those segments. However, segments are locked in memory and only
when the content of the page changes, a copy is made and the lock is transferred to the new segment.
Who Is Expected to Change This Tunable?
System administrators who wish to change the default copy-on-write behavior.
Restrictions on Changing
Changes to this tunable take effect immediately.
When Should the Tunable Be Turned Off?
If an application depends on copy-on-access behavior, where a process accessing a privately mapped file for the first time gets a copy of
the page and the contents of the page does not change unless private mapping writes to it, the tunable should be turned off to get copy-on-
access behavior.
What Are the Side Effects of Turning the Tunable Off?
Some workloads might see increased memory consumption since private segments are copied when accessed for the first time.
When Should the Tunable Be Turned On?
If an application wants industry standard semantics, which allows users to share data via private mapping of a file for which shared map-
ping exists, the tunable should be enabled. Turning the tunable on can also reduce memory consumption on some workloads since private seg-
ments are only copied upon write.
What Are the Side Effects of Turning the Tunable On?
Applications that privately map a file for which shared mapping exists can now see the updates performed by shared mapping.
What Other Tunables Should Be Changed at the Same Time?
None.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of
HP-UX.
Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun-
able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was
factory installed on your system, see at
AUTHOR
was developed by HP.
SEE ALSO fork(2), mlock(2), mmap(2).
Tunable Kernel Parameters copy_on_write(5)