Yes, shared memory is often not considered, because it can be used by many process - or it is counted several times.
A special type of shared memory is the SysV IPC (inter process communication), listed with
E.g. for the "Shared Memory" the listed PIDs are for the "Creator" and the "Last attacher".
Even the normal fork/exec to create a new process produces shared memory.
Because initially they are identical, they are not actually copied but the new process reuses the memory. They are really copied when the new process modifies it. This is called COW (copy on write).
Last edited by MadeInGermany; 10-29-2018 at 05:48 AM..
Hi All,
I have a question, can you guys please help me by giving your valuable suggestons:
I am using AIX 5L, running oracle 7 version. I need to increase the oracle memory to 40 MB more. Currently Oracle occupies 260M. I wanted to know whether I can increase the memory without any problem.... (1 Reply)
Hi All,
I have a question, can you guys please help me by giving your valuable suggestons:
I am using AIX 5L, running oracle 7 version. I need to increase the oracle memory to 40 MB more. Currently Oracle occupies 260M. I wanted to know whether I can increase the memory without any problem.... (3 Replies)
Hi,
We have AIX 5.1 machine of RAM 8 GB and paging space is 8GB. we are getting high memory usage of almost 99%.Can anybody please help in this ?
Partial vmstat o/p
kthr memory
----- -----------
r b avm fre
2 1 278727 1143
There is no paging issue.Becoz in... (5 Replies)
Hi Guys,
I wonder what would be the best way to determine how much memory is in use on any given time by the database processes. I thought about using ipcs -m command but I wonder if there any better way to determine this. Thanks.
Harby. (2 Replies)
Hi,
I have AIX 5.3TL8 two node cluster using HACMP and have 10g database using RAW devices. I am seeing gradual increase in comp% memory everyday and it reaches 100% and evicts the node, we had 4 evictions in 40days.
I am pasting vmstat and vmo output, anyone seen this issue?
... (5 Replies)
Hi All,
Anyone has script to monitor AIX total processes memory and cpu usage that contribute to the total memory and CPU utilize so far ?
The purpose of this is to analyze process memory trend.
Thanks.
Best Regards,
ckwan (2 Replies)
Hi All,
I have some questions regarding the performance, MEMORY/ Virtual Memory (paging /swap space)
Please see the nmon-MEMORY stats from my AIX LPAR.
24 GB --> RAM
3456 MB --> Paging Space
│ Memory ───────────────────────────────────────────────────────────────────────
│... (8 Replies)
Discussion started by: System Admin 77
8 Replies
LEARN ABOUT HPUX
plock
plock(2) System Calls Manual plock(2)NAME
plock() - lock process, text, data, stack, or shared library in memory
SYNOPSIS DESCRIPTION
The system call allows the calling process to lock the text segment of the process (text lock), its data segment (data lock), or both its
text and data segment (process lock) into memory. Stack segments are also locked when data segments are locked. Shared library text and
shared library data segments (shlib lock) can also be locked. Locked segments are immune to all routine swapping. also allows these seg-
ments to be unlocked.
The effective user ID of the calling process must be a user with the privilege.
op must be one of the following:
Lock text and data segments into memory (process lock)
Lock text segment into memory (text lock)
Lock data segment into memory (data lock)
Remove locks
Lock shared library text and shared library data segments (shared library lock)
Lock text, data and shared library text and shared library data segments
into memory (process and shared library lock)
Lock text, shared library text and shared library data segments into memory
(text and shared library lock)
Lock data, shared library text and shared library data segments into memory
(data and shared library lock)
Although and the family of functions may be used together in an application, each may affect the other in unexpected ways. This
practice is not recommended.
Security Restrictions
Some or all of the actions associated with this system call require the privilege. Processes owned by the superuser have this privilege.
Processes owned by other users may have this privilege, depending on system configuration. See privileges(5) for more information about
privileged access on systems that support fine-grained privileges.
RETURN VALUE
returns the following values:
Successful completion.
Failure.
The requested operation is not performed. is set to indicate the error.
ERRORS
If fails, is set to one of the following values.
op is equal to and a process lock, a text lock, or a data lock already exists on the calling process.
op is equal to and a text lock or process lock already exists on the calling process.
op is equal to and a data lock, or process lock already exists on the calling process.
op is equal to and no type of lock exists on the calling process.
op is equal to and there are no unlocked shared library segments in the calling process.
op is equal to and a process lock, a text lock, or a data lock already exists on the calling process.
op is equal to and a text lock or process lock already exists on the calling process.
op is equal to and a data lock, or process lock already exists on the calling process.
op is not equal to one of the values specified in
is not allowed in a
window. See vfork(2).
There is not enough lockable memory in the system
to satisfy the locking request.
The effective user ID of the calling process
is not a user with the privilege.
EXAMPLES
The following call to locks the calling process in memory:
SEE ALSO setprivgrp(1M), exec(2), exit(2), fork(2), getprivgrp(2), mlock(2), vfork(2), privileges(5).
STANDARDS CONFORMANCE plock(2)