Hi Derek, A simple recompile of the kernel with the higmem option enabled should be enough. Using the buildtool environment for it is the most convenient option (you don't have to apply the kernel patches by hand in that case).
Very interesting case by the way! Eric > 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=1216 >>> 42 >>> ---------------------------------------------------------------------- >>> -- >>> leaf-user mailing list: leaf-user@lists.sourceforge.net >>> 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: leaf-user@lists.sourceforge.net > 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: leaf-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/leaf-user Support Request -- http://leaf-project.org/
