Skip navigation.
Home
The QNX Community Portal

View topic - QNX 4.25 Free Memory

QNX 4.25 Free Memory

For the old QNX2 and QNX4 RTOS

QNX 4.25 Free Memory

Postby lrsweet » Tue Mar 12, 2013 7:56 pm

Can some one please tell me why the numbers shown with sin freemem don't agree with sin in?

In my case I have a machine with 2 gig of RAM so sin in shows:

Memory: 1712M/2048M

Sin freemem shows:
24576
8192
192512
57344
1753M
49152

Why do the individual chunks add up to more than the 1712M shown by sin in?

What is the best/most accurate way to determine system free memory?

Thanks.

Larry
lrsweet
New Member
 
Posts: 4
Joined: Tue Mar 12, 2013 7:48 pm

Re: QNX 4.25 Free Memory

Postby maschoen » Wed Mar 13, 2013 4:27 am

I doubt that anyone without the source code can tell you precisely why. A common error in coding is in using one of three different meanings to a Meg.

1,000,000
1024 x 1024
1024 x 1000

I've seen them all appear now and then. You run into the first more often with disk space. Disk manufacturers like to make their disks sound a big as possible.


I think that there are two likely possibilities for the QNX diference.
1) Someone made an error
2) The two numbers are calculating slightly different things

My guess would be 2).

I do feel like the difference, 43Meg seems large, however the percentage error 43/1753 ~ %2.4 is small. If you are crowding an application in tighter than that, you are playing with fire.
maschoen
QNX Master
 
Posts: 2640
Joined: Wed Jun 25, 2003 5:18 pm

Re: QNX 4.25 Free Memory

Postby lrsweet » Thu Mar 14, 2013 2:04 pm

Thanks Mitchell. Maybe someone from QNX will see this and take a look at the source ...

Not a show stopper for me but management was asking for tests to check for free memory.

I mentioned sin freemem and sin in.

Unfortunately they noticed the difference and are now asking why ...

Larry
lrsweet
New Member
 
Posts: 4
Joined: Tue Mar 12, 2013 7:48 pm

Re: QNX 4.25 Free Memory

Postby lrsweet » Fri Mar 15, 2013 11:51 am

Thanks Mitchell,

My management was asking about how to determine free memory.

I mentioned sin freemem and sin in.

Unfortunately after they used these they saw the difference between the two and are now asking why ...

Hopefully someone from QNX might see this and clear up the reason for the difference.

Thanks again.

Larry
lrsweet
New Member
 
Posts: 4
Joined: Tue Mar 12, 2013 7:48 pm

Re: QNX 4.25 Free Memory

Postby maschoen » Mon Mar 18, 2013 8:42 pm

This is QNX 4. It is very hard to get QNX people to look at QNX 4 and QNX 2 issues. For a long time it hasn't been possible to get them to look at QNX 6 Photon issues. So don't get your hopes up.
maschoen
QNX Master
 
Posts: 2640
Joined: Wed Jun 25, 2003 5:18 pm


Return to QNX2 and QNX4

Who is online

Users browsing this forum: No registered users and 1 guest