semaphore access speed Post: 302238994

Sponsored Content

Top Forums Programming semaphore access speed Post 302238994 by migurus on Monday 22nd of September 2008 03:07:44 PM

09-22-2008

Registered User

Quote:

Originally Posted by otheus

That's strange. Any chance you're running a different program that's elsewhere in the path? Try for instance running "./tstloop".

Also, for gprof, use the -l option (small L). I get:

.

to Jim:

tstloop is the only program, I did re-run
$ ./tstloop
$ gprof -l ./tstloop
gprof: gmon.out file is missing call-graph data

Thank you for taking it to other forum.

to Otheus:

tstloop compiled with profiling:

Code:

 
$ /usr/bin/time -vv ./tstloop
125000.00 semop/s [0,0]
Command exited with non-zero status 24
        Command being timed: "tstloop"
        User time (seconds): 15.05
        System time (seconds): 24.33
        Percent of CPU this job got: 99%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:39.39
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 121
        Voluntary context switches: 1
        Involuntary context switches: 326
        Swaps: 0
        File system inputs: 0
        File system outputs: 0
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 24

and here are results from program compiled without profiling

Code:

 
$ /usr/bin/time -vv ./tstloop
128205.13 semop/s [0,0]
Command exited with non-zero status 24
        Command being timed: "./tstloop"
        User time (seconds): 15.39
        System time (seconds): 23.19
        Percent of CPU this job got: 99%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:38.59
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 101
        Voluntary context switches: 1
        Involuntary context switches: 112
        Swaps: 0
        File system inputs: 0
        File system outputs: 0
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 24

migurus

View Public Profile for migurus

Find all posts by migurus

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

semaphore

hi, is there any command where we can monitor semaphores?

2. UNIX for Dummies Questions & Answers

Semaphore

Hi, I'm new to UNIX. I need to know what's a semaphore Do reply. Thanks VJ

3. Filesystems, Disks and Memory

dmidecode, RAM speed = "Current Speed: Unknown"

Hello, I have a Supermicro server with a P4SCI mother board running Debian Sarge 3.1. This is the "dmidecode" output related to RAM info: RAM speed information is incomplete.. "Current Speed: Unknown", is there anyway/soft to get the speed of installed RAM modules? thanks!! Regards :)...

4. Shell Programming and Scripting

Semaphore

Hi, I am looking to use a semaphore for the first time in one of my scripts. I am just wondering if there are any simple examples or tutorials around? I am a beginner so the simpler the better :) Thanks -Jaken

5. UNIX for Dummies Questions & Answers

semaphore

what is semaphore? can any body explain it in a more simple way than the manual ?? replies appreciated Regards raguram R

6. Filesystems, Disks and Memory

data from blktrace: read speed V.S. write speed

I analysed disk performance with blktrace and get some data: read: 8,3 4 2141 2.882115217 3342 Q R 195732187 + 32 8,3 4 2142 2.882116411 3342 G R 195732187 + 32 8,3 4 2144 2.882117647 3342 I R 195732187 + 32 8,3 4 2145 ...

7. Shell Programming and Scripting

semaphore

Control two exclusively shared resources(semaphore). The two resources are two files. The producer will write even numbers to one file, and odd numbers to another one. The consumer respectively reads from each file until it gets 5 even numbers and 5 odd numbers. Can any one help me with the...

8. Programming

Semaphore

If I create a semaphore and then I fork a number of child processes then all the child process use that same semaphore. Since the process address spaces are different rfom each other then how all the child process are able to access the same semaphore? I understand that semaphore/mutex is at os...

9. UNIX for Beginners Questions & Answers

Semaphore

I was asked to add this piece of code to a c program which I will execute through the shell: for(long i = 0; i < NITER; i++) { sem_wait( &sema); count++; sem_post( &sema); } I didn't get it, which is the critical section ? if it's "count++" how would a thread wake up in order to enter it...

LEARN ABOUT PHP

sem_get

SEM_GET(3)								 1								SEM_GET(3)

sem_get - Get a semaphore id

SYNOPSIS

       resource sem_get (int  $key, [int  $max_acquire = 1], [int  $perm = 0666], [int	$auto_release = 1])

DESCRIPTION

       sem_get(3) returns an id that can be used to access the System V semaphore with the given $key.

	A second call to sem_get(3) for the same key will return a different semaphore identifier, but both identifiers access the same underlying
       semaphore.

PARAMETERS

	      o $key
		-

	      o $max_acquire
		- The number of processes that can acquire the semaphore simultaneously is set to $max_acquire.

	      o $perm
		- The semaphore permissions. Actually this value is set only if the process finds it is the only process currently attached to the
		semaphore.

	      o $auto_release
		- Specifies if the semaphore should be automatically released on request shutdown.

RETURN VALUES

	Returns a positive semaphore identifier on success, or FALSE on error.

CHANGELOG

       +--------+-----------------------------------------+
       |Version |					  |
       |	|					  |
       |	|		Description		  |
       |	|					  |
       +--------+-----------------------------------------+
       | 4.3.0	|					  |
       |	|					  |
       |	|  The $auto_release parameter was added. |
       |	|					  |
       +--------+-----------------------------------------+
NOTES

       Warning

	       When using sem_get(3) to access a semaphore created outside PHP, note that the semaphore must have been created as a set of 3 sema-
	      phores (for example, by specifying 3 as the nsems parameter when calling the C semget() function), otherwise PHP will be	unable	to
	      access the semaphore.

SEE ALSO

       sem_acquire(3), sem_release(3), ftok(3).

PHP Documentation Group 														SEM_GET(3)

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

semaphore

Discussion started by: yls177

2. UNIX for Dummies Questions & Answers

Semaphore

Discussion started by: vjsony

3. Filesystems, Disks and Memory

dmidecode, RAM speed = "Current Speed: Unknown"

Discussion started by: Santi

4. Shell Programming and Scripting

Semaphore

Discussion started by: Jaken

5. UNIX for Dummies Questions & Answers

semaphore

Discussion started by: raguramtgr

6. Filesystems, Disks and Memory

data from blktrace: read speed V.S. write speed

Discussion started by: W.C.C

7. Shell Programming and Scripting

semaphore

Discussion started by: gokult

8. Programming

Semaphore

Discussion started by: rupeshkp728

9. UNIX for Beginners Questions & Answers

Semaphore

Discussion started by: uniran

LEARN ABOUT PHP

sem_get