Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Mon, 26 Jun 2006 09:47:00 +0200

Steven,
when pthread_create() fails, it is probably a problem with stack space
rather than heap. Each thread gets its own stack space in 2 of the 4 GB
address space of a 32bit machine. This results in a limitation in the
number of threads, i.e. the number of IOCs, the gateway can conenct to.
Solution: reduce the stack size for each thread:
ulimit -s 4096
BTW: You can get the same problem with any CA client which connects to
many IOCs.
Dirk

Steven Banks wrote:

We are having severe problems with the EPICS gateway, and I'm hoping
that someone can help us resolve them.

The problem is that the gateway is continually crashing whenever we open
up a GUI display with requires connection to multiple IOCs. These are
Libera BPM boxes, and we have 98 of them. We have a status display
which shows the status of 33 of these at once. As we scroll from one
display to the other, the gateway invariably crashes.

(This is a gateway between our office network and our accelerator
network, and is used for monitoring the status of the machine from our
desktops.)

The gateway log provides the following information:

***************************************************************

Jun 26 16:01:02 PV Gateway Version 2.0.0.0 [Jun 14 2006 15:10:22]

EPICS 3.14.6 PID=8840 ServerPID=8839

EPICS_CA_ADDR_LIST=BROADCAST-ACC

EPICS_CA_AUTO_ADDR_LIST=NO

EPICS_CA_SERVER_PORT=Not specified

EPICS_CA_MAX_ARRAY_BYTES=Not specified

EPICS_CAS_INTF_ADDR_LIST=CR01GW01-OFFICE

EPICS_CAS_SERVER_PORT=Not specified

EPICS_CAS_IGNORE_ADDR_LIST=Not specified

Running as user ics on host CR01GW01

Statistics PV prefix is CR01GW01

pthread_create error Cannot allocate memory

Jun 26 16:36:12 !!! Errlog message received (message is above)

fatal error: epicsThreadCreate

Jun 26 16:36:12 !!! Errlog message received (message is above)

***************************************************************

Has anyone else seen the memory problems that we are experiencing? Is
this an indication that we are trying to connect to too many PVs at
once? Will purchasing more memory for the gateway perhaps alleviate the
problem. It currently has 512MB but we are planning to upgrade it to 1 GB.

Dr. Steven M. Banks – Control Systems Engineer

Australian Synchrotron Project

Major Projects Victoria

800 Blackburn Road

CLAYTON VIC 3168

tel: +613 8540 4103

fax: +613 8540 4200
mailto:[email protected]
http://www.synchrotron.vic.gov.au <http://www.synchrotron.vic.gov.au/>

--
Dr. Dirk Zimoch
Swiss Light Source
Paul Scherrer Institut
Computing and Controls
phone +41 56 310 5182
fax   +41 56 310 4413

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System