Eric, Thanks for the prompt reply.
I understand the reason - in this case I was looking at running BGP with a full set of internet routes ( about 400,000 at the last count), and I dont want the system to have any chance of running out of memory. I have a "Redhat" type system currently doing the job and seems to be using 1.3Gb memory. The only reason for using a Leaf distro is to get rid of the HDD as a point of failure. What would be involved in getting a kernel with this limit lifted? Regards, Derek Eric Spakman wrote: > Hi Derek, > > >> I have leaf Bering uclib running on a box with 2Gb memory but it only >> show 1Gb in /proc/meminfo >> >> Is possibly a limit in Leaf or have is it likely I have a hardware >> problem? >> >> > It's because the kernel is compiled with "CONFIG_NOHIGHMEM=y" in the > kernel config. Bering-uClibc is an embedded distro, using 2G of memory is > really overkill. > > From the kernel documentation: > > "CONFIG_NOHIGHMEM > Linux can use up to 64 Gigabytes of physical memory on x86 systems. > However, the address space of 32-bit x86 processors is only 4 Gigabytes > large. That means that, if you have a large amount of physical memory, not > all of it can be "permanently mapped" by the kernel. The physical memory > that's not permanently mapped is called "high memory". > > If you are compiling a kernel which will never run on a machine with more > than 960 megabytes of total physical RAM, answer "off" here (default > choice and suitable for most users). This will result in a "3GB/1GB" > split: 3GB are mapped so that each process sees a 3GB virtual memory space > and the remaining part of the 4GB virtual memory space is used by the > kernel to permanently map as much physical memory as possible. > > If the machine has between 1 and 4 Gigabytes physical RAM, then answer > "4GB" here. > > If more than 4 Gigabytes is used then answer "64GB" here. This selection > turns Intel PAE (Physical Address Extension) mode on. PAE implements > 3-level paging on IA32 processors. PAE is fully supported by Linux, PAE > mode is implemented on all recent Intel processors (Pentium Pro and > better). NOTE: If you say "64GB" here, then the kernel will not boot on > CPUs that don't support PAE! > > The actual amount of total physical memory will either be auto detected or > can be forced by using a kernel command line option such as "mem=256M". > (Try "man bootparam" or see the documentation of your boot loader (grub, > lilo or loadlin) about how to pass options to the kernel at boot time.) > > If unsure, say "off". > " > > Eric > > >> TIA >> >> >> Derek >> >> >> ------------------------------------------------------------------------- >> Using Tomcat but need to do more? Need to support web services, >> security? Get stuff done quickly with pre-integrated technology to make >> your job easier Download IBM WebSphere Application Server v.1.0.1 based on >> Apache Geronimo >> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 >> ------------------------------------------------------------------------ >> leaf-user mailing list: [email protected] >> https://lists.sourceforge.net/lists/listinfo/leaf-user >> Support Request -- http://leaf-project.org/ >> >> >> > > > ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ------------------------------------------------------------------------ leaf-user mailing list: [email protected] https://lists.sourceforge.net/lists/listinfo/leaf-user Support Request -- http://leaf-project.org/
