It's based on knowing only Windows API calls. There is an API there, VirtualAlloc that allocates virtual -per the description anyway- memory (swapfile space).
On SunOS 5.8 I get an error when starting a large Java process with over 2Gb memory.
Error occurred during initialization of VM
Could not reserve enough space for object heap
When stopping several other Java processes we can start this process. This seems to indicate that we don't have... (11 Replies)
Hi,
I have 2 systems with same hardware and software. One system is giving me error "Error occurred during initialization of VM Could not reserve enough space for object " when I tried to increase JBoss App's heap size to 2GB while the other system is running fine without any issue. Is there... (5 Replies)
hi... i want to find oracle allocate how many memory really..
i execute this code to list memory on unix system : ps -eo pmem,args | sort -k 1 -r -n
outputs ;
%mem command
12.9|ora_smon_RTX
12.9|ora_s000_RTX
12.9|ora_reco_RTX
12.9|ora_qmnc_RTX... (2 Replies)
Hi,
In my proj, one process was running for 2 days. after 2 days its throwing an error message "shmget failed cannot allocate memory". the same problem happened every time.i.e. i can reproduce the same issue if my process is running for every 2 days for a same operation.Within this 2 days there... (1 Reply)
Hi,
In my proj, one process was running for 2 days. after 2 days its throwing an error message "shmget failed cannot allocate memory". the same problem happened every time.i.e. i can reproduce the same issue if my process is running for every 2 days for a same operation.Within this 2 days there... (1 Reply)
Hi,
In my proj, one process was running for 2 days. after 2 days its throwing an error message "shmget failed cannot allocate memory". the same problem happened every time.i.e. i can reproduce the same issue if my process is running for every 2 days for a same operation.Within this 2 days there... (1 Reply)
hi
I want to take string as a input from user and the string is very very length. From the lengthy string i have to substring take first 16 letters, then next 8 letters,................... Please guide me how to write program to take lengthy string from user and sub string it.
Thanks (4 Replies)
On SunOS 10 get an error when starting a large Java process with over 2Gb memory.
Error occurred during initialization of VM
Could not reserve enough space for object heap
i have 32G memory !! , swap = 31G
Please any advice !!! (3 Replies)
Hi , experts.
I work on Linux station (RedHat 5.7), regular user, but have root password.
%> uname -a
Linux ran1log06 2.6.18-238.1.1.el5 #1 SMP Tue Jan 4 13:32:19 EST 2011 x86_64 x86_64 x86_64 GNU/Linux
%> cat /etc/issue
Red Hat Enterprise Linux Client release 5.7 (Tikanga)
Kernel \r on... (5 Replies)
Discussion started by: baruchgu
5 Replies
LEARN ABOUT LINUX
shm_overview
SHM_OVERVIEW(7) Linux Programmer's Manual SHM_OVERVIEW(7)NAME
shm_overview - Overview of POSIX shared memory
DESCRIPTION
The POSIX shared memory API allows processes to communicate information by sharing a region of memory.
The interfaces employed in the API are:
shm_open(3) Create and open a new object, or open an existing object. This is analogous to open(2). The call returns a file descriptor
for use by the other interfaces listed below.
ftruncate(2) Set the size of the shared memory object. (A newly created shared memory object has a length of zero.)
mmap(2) Map the shared memory object into the virtual address space of the calling process.
munmap(2) Unmap the shared memory object from the virtual address space of the calling process.
shm_unlink(3) Remove a shared memory object name.
close(2) Close the file descriptor allocated by shm_open(3) when it is no longer needed.
fstat(2) Obtain a stat structure that describes the shared memory object. Among the information returned by this call are the
object's size (st_size), permissions (st_mode), owner (st_uid), and group (st_gid).
fchown(2) To change the ownership of a shared memory object.
fchmod(2) To change the permissions of a shared memory object.
Versions
POSIX shared memory is supported since Linux 2.4 and glibc 2.2.
Persistence
POSIX shared memory objects have kernel persistence: a shared memory object will exist until the system is shut down, or until all pro-
cesses have unmapped the object and it has been deleted with shm_unlink(3)
Linking
Programs using the POSIX shared memory API must be compiled with cc -lrt to link against the real-time library, librt.
Accessing shared memory objects via the file system
On Linux, shared memory objects are created in a (tmpfs) virtual file system, normally mounted under /dev/shm. Since kernel 2.6.19, Linux
supports the use of access control lists (ACLs) to control the permissions of objects in the virtual file system.
CONFORMING TO
POSIX.1-2001.
NOTES
Typically, processes must synchronize their access to a shared memory object, using, for example, POSIX semaphores.
System V shared memory (shmget(2), shmop(2), etc.) is an older shared memory API. POSIX shared memory provides a simpler, and better
designed interface; on the other hand POSIX shared memory is somewhat less widely available (especially on older systems) than System V
shared memory.
SEE ALSO fchmod(2), fchown(2), fstat(2), ftruncate(2), mmap(2), mprotect(2), munmap(2), shmget(2), shmop(2), shm_open(3), shm_unlink(3), sem_over-
view(7)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2010-09-10 SHM_OVERVIEW(7)