64 meg memory cap on QNX4?

We noticed that QNX 4 only shows 65 megs of installed memory even though the
bios can see 512 megs. Why doesn’t QNX 4 see more than 64 megs and why does
the system go haywire if that 64 megs runs out.

Background:

We have systems set up for several customers on a QNX 4 version 4.25 D
platform with 512 megs of RAM.

Over time we have noticed that mysteriously on some locations we start
having system problems with databases doing unexplainable things or programs
crashing. Lately we finally found a pattern.

When “sysmon m=topmem” reports that there is like 99% free memory,
everything works fine.

But eventually most of these systems start reporting 1% or 0% free memory,
at which time fsys, dev32, dev32.ansi and network activity take up 100% of
the cpu cycles. This is 0% of 65 megs RAM and not of the 512 megs that we
actually have.

On boot up or even when our software is not running (just the OS sitting
there idle) the memory often shows only 4% to 20% free and always only shows
65 megs.

We were told that QNX4 supports one gigabyte of RAM, yet this does not seem
to be the case.

Any assistance would be greatly appreciated. Thank you very much.

Gil Lande

Have you tried to run ramtrap?

It sounds like your application may have a memory leak. If that’s the
case, adding the additional memory is only a temporary fix. Eventually
even 512 MB of ram could be consumed.


Previously, David F. Marker wrote in qdn.public.qnx4:

We noticed that QNX 4 only shows 65 megs of installed memory even though the
bios can see 512 megs. Why doesn’t QNX 4 see more than 64 megs and why does
the system go haywire if that 64 megs runs out.

Background:

We have systems set up for several customers on a QNX 4 version 4.25 D
platform with 512 megs of RAM.

Over time we have noticed that mysteriously on some locations we start
having system problems with databases doing unexplainable things or programs
crashing. Lately we finally found a pattern.

When “sysmon m=topmem” reports that there is like 99% free memory,
everything works fine.

But eventually most of these systems start reporting 1% or 0% free memory,
at which time fsys, dev32, dev32.ansi and network activity take up 100% of
the cpu cycles. This is 0% of 65 megs RAM and not of the 512 megs that we
actually have.

On boot up or even when our software is not running (just the OS sitting
there idle) the memory often shows only 4% to 20% free and always only shows
65 megs.

We were told that QNX4 supports one gigabyte of RAM, yet this does not seem
to be the case.

Any assistance would be greatly appreciated. Thank you very much.

Gil Lande

We have several QNX4 machines running 128 meg of DRAM, one running 768 meg and
one running 1 gig with no problems or use of “ramtrap” whatsoever. Looks like
Proc32 4.25J is what we’re running (I’m not sure what release level that is).
So from my experience, the 1 gig memory thing does indeed appear to work in
QNX4. There’s some sinister issue hiding in your configuration somewhere, I
betcha.

-Warren “I forget what’s the first thing to go” Peece



“David F. Marker” <interprotech@ameritech.net> wrote in message
news:9ivc0u$p4t$1@inn.qnx.com
| We noticed that QNX 4 only shows 65 megs of installed memory even though the
| bios can see 512 megs. Why doesn’t QNX 4 see more than 64 megs and why does
| the system go haywire if that 64 megs runs out.
|
| Background:
|
| We have systems set up for several customers on a QNX 4 version 4.25 D
| platform with 512 megs of RAM.
|
| Over time we have noticed that mysteriously on some locations we start
| having system problems with databases doing unexplainable things or programs
| crashing. Lately we finally found a pattern.
|
| When “sysmon m=topmem” reports that there is like 99% free memory,
| everything works fine.
|
| But eventually most of these systems start reporting 1% or 0% free memory,
| at which time fsys, dev32, dev32.ansi and network activity take up 100% of
| the cpu cycles. This is 0% of 65 megs RAM and not of the 512 megs that we
| actually have.
|
| On boot up or even when our software is not running (just the OS sitting
| there idle) the memory often shows only 4% to 20% free and always only shows
| 65 megs.
|
| We were told that QNX4 supports one gigabyte of RAM, yet this does not seem
| to be the case.
|
| Any assistance would be greatly appreciated. Thank you very much.
|
| Gil Lande
|
|

This issue goes back a few years, but IIRC ramtrap was introduced
specifically because memory wasn’t always detected properly in
compaq machines. Some machines use a different mechanism to detect
memory beyond some particular threshold.

Like you, I have never needed ramtrap.

Previously, Warren Peece wrote in qdn.public.qnx4:

We have several QNX4 machines running 128 meg of DRAM, one running 768 meg and
one running 1 gig with no problems or use of “ramtrap” whatsoever. Looks like
Proc32 4.25J is what we’re running (I’m not sure what release level that is).
So from my experience, the 1 gig memory thing does indeed appear to work in
QNX4. There’s some sinister issue hiding in your configuration somewhere, I
betcha.

-Warren “I forget what’s the first thing to go” Peece

[…]

On one of our Compaq machines, we had to add the -M parameter to the
boot line in the hard.n file. It was something like…

$ boot -v -M70254592,30408704

which is (if I can remember…) the start and size of the memory to be added.

~ Jeff

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/ \ | __ ) | ~Jeffrey Jordan jordanj@abc-naco.com
/ | \ | _ ( Phone: (610)630-2330x216 jljordan@wans.net
/ ++ \ | ) (
Fax: (610)630-2323
|
| |||/_| 2550 Blvd. o/t Generals, Norristown PA 19403
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Ken Schumm wrote:

This issue goes back a few years, but IIRC ramtrap was introduced
specifically because memory wasn’t always detected properly in
compaq machines. Some machines use a different mechanism to detect
memory beyond some particular threshold.

Like you, I have never needed ramtrap.

Previously, Warren Peece wrote in qdn.public.qnx4:
We have several QNX4 machines running 128 meg of DRAM, one running 768 meg and
one running 1 gig with no problems or use of “ramtrap” whatsoever. Looks like
Proc32 4.25J is what we’re running (I’m not sure what release level that is).
So from my experience, the 1 gig memory thing does indeed appear to work in
QNX4. There’s some sinister issue hiding in your configuration somewhere, I
betcha.

-Warren “I forget what’s the first thing to go” Peece

[…]