Date: Thu, 11 Dec 2003 13:55:11 -0300 From: "Nicolas Gieczewski" <nicolas@nixsoftware.com> To: <freebsd-java@freebsd.org> Subject: Re: How's linux-ibm-jdk14 in the memory footprint department? Message-ID: <030b01c3c007$9c619210$0200a8c0@veggy.org> References: <2946E9F05C8DD511A7DC0002A5608CE4DB2015@gbchm201.exgb01.exch.eds.com>
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Thanks for the suggestion. I could only get it down to about 152 MB with = an initial heap size of 8 MB and a maximum size of 16 MB. I believe this = is probably too small, though (actually, I have no idea, guess I'll have = to see how often the GC is kicking in). Even though not all of the 152 = MB (or 203 MB, for that matter) are in main memory at any given time, = don't they become unavailable to the OS, anyway? Nevertheless, it's still pretty much of a memory hog even with such a = tiny heap. On Windows, its total memory footprint is around 23 MB as I = had said, with only about half of that in main memory at any given time. = Do you know how I can check the default heap size of the JVM? I'd like = to compare default heap sizes on *nix and Windows and see what the JVM's = memory footprint is on each platform without counting the heap. Thanks again! Nick ----- Original Message -----=20 From: "Sparrevohn, Thomas" <thomas.sparrevohn@eds.com> To: "'Nicolas Gieczewski'" <foo@bar.org>; <freebsd-java@freebsd.org> Sent: Wednesday, December 10, 2003 22:07 Subject: RE: How's linux-ibm-jdk14 in the memory footprint department? Allow me to take a look at it tomorrow. The RSS I have seen I was about = 40MB or so and there no doubt that it will present a problem on a 64MB = host - It seems to start with a quite high default heap - around 128MB - = But I need to verify it. Have you tried to limit the Heap? It is quite = normal for Heaps to like "huge" areas of memory but it does not mean = that it is needed. -- Thomas -----Original Message----- From: owner-freebsd-java@freebsd.org = [mailto:owner-freebsd-java@freebsd.org] On Behalf Of Nicolas Gieczewski Sent: 10 December 2003 19:08 To: freebsd-java@freebsd.org Subject: Re: How's linux-ibm-jdk14 in the memory footprint department? Well, naturally the 203 MB cannot be in physical memory all at the same = time on a box with 64 MB of RAM, but the JVM's total memory footprint = (text + code + data) is 203 MB, and I can feel it in the constant disk = paging taking place while it's running. I'm still hoping someone using IBM's JVM will eventually get back to me = and tell me its memory footprint is around the same, so that I won't get = an urge to reboot for USER_LDT to take effect in order to be able to use = linux-ibm-jdk14 instead :-) Cheers, Nick ----- Original Message -----=20 From: "Sparrevohn, Thomas" <thomas.sparrevohn@eds.com> To: "'Nicolas Gieczewski'" <foo@bar.org>; <freebsd-java@freebsd.org> Sent: Wednesday, December 10, 2003 10:49 Subject: RE: How's linux-ibm-jdk14 in the memory footprint department? The real memory usage is much smaller - I would think that it is because = it allocated the memory range but never actually uses it.=20 -----Original Message----- From: owner-freebsd-java@freebsd.org = [mailto:owner-freebsd-java@freebsd.org] On Behalf Of Nicolas Gieczewski Sent: 09 December 2003 18:13 To: freebsd-java@freebsd.org Subject: Re: How's linux-ibm-jdk14 in the memory footprint department? Hello Gabriel, Thank you for your response. I doubt it's the GC, for memory usage jumps = to those values right after the VM starts, i.e. when there's not much to = garbage collect yet. Also, it says around those figures for the rest of = the program's lifetime. This is a console application, by the way. What I'd like to know is whether IBM's implementation of the JVM happens = to use a little less memory. I think 203 MB is too much for a console = application, and that box only has 64 MB of RAM. I did install = linux-ibm-jdk14 to check this myself, but found out it requires the = USER_LDT setting in the kernel, and I can't reboot because of a stupid = setting since I'm running important services on the box. Any linux-ibm-jdk14 fans out there? Thanks, Nick ----- Original Message -----=20 From: "Gabriel Ambuehl" <gabriel_ambuehl@buz.ch> Cc: <freebsd-java@freebsd.org> Sent: Tuesday, December 09, 2003 13:01 Subject: Re: How's linux-ibm-jdk14 in the memory footprint department? Hello Nicolas, Tuesday, December 9, 2003, 3:57:10 PM, you wrote: > Hello, > Sun's VM eats up ~203 MB of memory to run a small program on my > FreeBSD box, whereas on Windows it only uses ~23 MB. Besides not=20 > understanding how the difference can be so big, I wonder if anyone has = > tried linux-ibm-jdk14? Is it a memory hog like Sun's? Are you sure this isn't just some Garbage collector behaving = differently? Best regards, Gabriel
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