2008/11/25 Sascha Silbe <[EMAIL PROTECTED]>: > On Tue, Nov 25, 2008 at 08:47:16AM +0100, Marcus Wolschon wrote: > >> Okay, on a big AMD-multicore-laptop the limit in Java seems to be >> 1GB of memory-mapped files. > > That's pretty small given that kernel/user split is usually 2G/2G or even > 3G/1G... > >> Ulimit was "unlimited" and --XX:MaxDirectMemorySize was set to 32GB >> -Xmx was a few GB. I am using the current Java6 -patchlevel 10 from >> Sun. > > Have you tried using a smaller -Xmx size? I have the impression that Java > allocates the maximum allowed size directly on startup, relying on the OS to > do lazy allocation of pages. If that's the case, reducing -Xmx should > increase free virtual address space, allowing bigger memory mappings.
It does not. Xmx is the maximum size, Xms would be the initial and it used no more then a few dozen megabyte or heap-space acording to jconsole. >> I'd like to try this on a 64bit-Linux on that box but don't know how to >> do that yet. Any help on turning a debian 32bit into a 64-bit or running >> a 64bit-VM in a 32bit-Linux? > > I don't think that's possible. Both 32bit and 64bit userspace and emulation > work with a 64bit kernel, but at least 64bit userspace on a 32bit kernel > isn't possible. I'm not talking about native execution but a virtual machine with qemu or Vmware that emulates all of the hardware. >From what I could find at least qEmu should be able to emulate all the guest-architectures (including x86-64, PPC and Sparc32/64) on an x86-32 host. Marcus _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
