I've been doing some reading lately about threading (Posix threads) and I'm really curious about a couple things that I've read. I'm not sure if many people here have threading experience, but I thought it would be nice to be able to discuss some questions about it.
(For the record, I did... (1 Reply)
Hi,
I have written a code which will run a set of process using
fork.
I want to know from You how can i start another job when one of my job in my loop is completed
My code is
#include<stdio.h>
#include<ctype.h>
main() {
int pid,cid;
ChildProcess();
... (1 Reply)
Hi All,
Here's my question
I have a 385 MB file containing 5,000,000 records.
I need to read from the file and load into a table.
Initially i thought of doing it in a single thread (execution of a single program) but when calculated accounted 16 hours of time on a standard benchmark.
Hence... (5 Replies)
Sir,
Can I call same function in the start routines of different Threads.
I have created two different threads....and wanna call same function from both threads....is it possible???
Also can I fork inside a thread??? (1 Reply)
Hi, If we create 10 threads to invoke runQuery method at same time, Will queryProcessor will be overriden sometime or 10 different copies will be created?
We are not using any sunchronzation mechnism in runQuery(). so there is not gurantee on QueryProcessor class variables right OR each 10... (1 Reply)
In this piece i implemented the gossip method. The first thread is invoked from inside the (msg is first sent from node -1 to 0 from main()) and the other threads are invoked from inside of the thread function itself. I used two mutexes and a condition variable to control the synchronization. ... (4 Replies)
Hi, I am trying to get my head round Multi Threading and I have a few queries to try and clear up my confusion
Q1. Is multi threading a hardware / chip level concept, an OS level or an application level concept ? I am trying to work out where SMT architecture fits in.
Q2. What's the multi... (3 Replies)
Not just background process running ... but im looking if unix has any multi-threading concept like in Java, C# ... if not present, can you pls share the nearest feature in unix that is close to multi-threaded concept (3 Replies)
Hi,
Can we apply multi threading in Unix. I am using bash shell.
We have a generic script to load the data to table based on file input. For each file there is an individual table to load.
For each file found in directory I want to load the data in parallel to target table using
... (3 Replies)
Discussion started by: vedanta
3 Replies
LEARN ABOUT HPUX
lcpu_attr
lcpu_attr(5) File Formats Manual lcpu_attr(5)NAME
lcpu_attr - dynamically enable or disable LCPU attribute of the default processor set
VALUES
Fail Safe
Default
the LCPU attribute of the default processor set is disabled
Allowed values
or
DESCRIPTION
This tunable dynamically enables or disables the logical processor (LCPU) attribute in the default processor set. On systems supporting
hyper-threading technology, each hyper-thread is represented as an LCPU.
When the LCPU attribute is enabled, the processor cores in the default processor have hyper-threading enabled. If the LCPU attribute is
disabled, the physical processors in the default processor set behave as single threaded processor cores.
See pset_setattr(2) for information about managing the LCPU attribute in processor sets other than the default processor set.
Who Is Expected to Change This Tunable?
System administrators that wish to change hyper-threading ability in the default processor set.
Restrictions on Changing
The tunable has no effect on platforms that do not have hyper-threading capability or systems with hyper-threading disabled at the firmware
level. On systems that support hyper-threading, the firmware feature must be enabled to dynamically enable/disable the LCPU attribute in
the default processor set.
When Should the Tunable Be Turned On?
The tunable should be turned on to enable the LCPU attribute in the default processor set to take advantage of hyper-threading. If the
applications running on the system see performance benefits, the LCPU attribute should remain enabled.
What Are the Side Effects of Turning the Tunable On?
Some workloads may experience performance degradation when the LCPU attribute is enabled.
When Should the Tunable Be Turned Off?
Some applications may experience performance degradation or may not see any performance benefits from using hyper-threading. In this case,
this tunable should be turned off.
What Are the Side Effects of Turning the Tunable Off?
With LCPU turned off, applications may not take advantage of hyper-threading.
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 psrset(1M), pset_assign(2), pset_bind(2), pset_create(2), pset_ctl(2), pset_destroy(2), privgrp(4).
Tunable Kernel Parameters lcpu_attr(5)