Hi, are you sure? you can address 4G but for the design of the kernel you only have 2GB http://kerneltrap.org/node/2450 http://web.archive.org/web/20080424081633/lwn.net/Articles/75174/ <http://web.archive.org/web/20080424081633/lwn.net/Articles/75174/>thanks, ESG 2010/3/17 Nigel Wade <nmw@xxxxxxxxxxxx> > ESGLinux wrote: > > Hi, > > > > I´m reading a post about the memory use for a java application: > > > http://web.archive.org/web/20080313075240/http://goobsoft.homeip.net/Wiki.jsp?page=JavaDebianTuning > > > > and there is a thing that surprise me: > > Read this and to the point where you understand that a 32-process on > Linux > > only has 2GB of addressible space. In fact, back in 1999, Linus decreed > that > > 32-bit Linux would never, ever support more than 2GB of memory. "This is > not > > negotiable." > > > > So I have a machine running RHEL x64 but I have a process that run over > > only 32 bit (the JVM), Reading this I think my process only can use 2Gb > of > > memory. > > > > is it true? is it oficial documented anywhere? > > > > Thanks in advance, > > > > ESG > > > No, the 32bit address space limit is 4GB, not 2GB. > > $ java -Xmx3500m -version > java version "1.6.0_15" > Java(TM) SE Runtime Environment (build 1.6.0_15-b03) > Java HotSpot(TM) Server VM (build 14.1-b02, mixed mode) > > $ java -Xmx4500m -version > Invalid maximum heap size: -Xmx4500m > The specified size exceeds the maximum representable size. > Could not create the Java virtual machine. > > If you want more address space than this use a 64bit JVM. > Using a 64bit JVM then: > > $ java -Xmx4500m -version > java version "1.6.0_17" > Java(TM) SE Runtime Environment (build 1.6.0_17-b04) > Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01, mixed mode) > > -- > Nigel Wade, System Administrator, Space Plasma Physics Group, > University of Leicester, Leicester, LE1 7RH, UK > E-mail : nmw@xxxxxxxxxxxx > Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555 > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
