You should look at the code segment size in addtion to the the objects created (heap). Sometimes, large shared files are loaded into memory. For example, 10Mb for leading Oracle's OCI driver.
Other sources of memory consumption include overhead (stacks) related to threads. If you have a Tomcat server kicking off 75 threads (maxProcessors for an Ajp connector). Then you will have 75 stacks at the default 1Mb size. These two cases could account for 85Mb of you 140Mb memory. Add in your 30Mb heap, some Java classes like rt.jar, some native code like libjvm, and you'll be at 140 Mb before you know it. ----- Original Message ----- From: Allistair Crossley <[EMAIL PROTECTED]> Date: Friday, January 30, 2004 10:03 am Subject: Available JVM Heap vs WTM Process Memory .. Continued > Hi, > > I know this has been put forward a few times but I have not been > satisfied with the answers given and I again raise the question > after having done some playing with JProfiler yesterday. > > The difference between JProfiler's heap available/heal used > telemetry view and the process memory consumption listed in the > Windows Task Manager. > > So far the debate has pretty much arrived at the conclusion that > both the Java runtime and Windows itself have overheads that get > added into the process memory view but that this amount is not > particularly substantial. > > When I start TC5.0.18 and just leave it the WTM process memory is > around 37MB. The JProfiler heap available is 10MB and the amount of > this used is around 7-8MB. > > I put the first few requests in to my application and make it do a > lot of stuff (searches and navigation operations). The WTM memory > continues to increase up to about 65MB. Looking at JProfiler's view > I see that the heap available has had to grow to 20MB BUT the > garbage collectors has been kicking in quite often and has managed > to get the used amount back to around 10MB. > I understand that when the jvm heap needs to grow, then it shall do > and then it keeps a handle on that memory so it is right that the > WTM view does not then start decreasing. Fine. > > At the end of the day the WTM memory is up to 140MB however the > maximum heap available in JProfiler never got over 30MB. Now, to my > mind, if I had a memory leak of some kind I would see JProfiler > reporting a larger available heap. I would see JProfiler reporting > surely that the heap has had to grow to over 100MB if the WTM > manages to get so high. > > Apart from memory leaks (which I cannot see evidence for since > every report in JProfiler indicates that most memory, classes, cpu > time and so on is used by org.apache related stuff) are there any > other reasons? > > ADC > > > <FONT SIZE=1 FACE="VERDANA,ARIAL" COLOR=BLUE> > ------------------------------------------------------- > QAS Ltd. > Developers of QuickAddress Software > http://www.qas.com";>www.qas.com > Registered in England: No 2582055 > Registered in Australia: No 082 851 474 > ------------------------------------------------------- > </FONT> > > > -------------------------------------------------------------------- > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
