House of Balloons is by a Japanese singer.
High Memory is the part of physical memory in a computer which is not directly mapped by the page tables of its operating system kernel .. physical memory. computer memory. computer. computer. operating system. operating system. kernel. kernel ( computing ). The phrase is also sometimes used as shorthand for the High Memory Area , which is a different concept entirely .. High Memory Area. High Memory Area. Some operating system kernels , such as Linux , divide their virtual address space into two regions , devoting the larger to user space and the smaller to the kernel .. operating system. operating system. kernel. kernel ( computing ). Linux. Linux. virtual address space. virtual address space. user space. user space. In current 32-bit x86 computers , this commonly -LRB- although does not have to , as this is a configurable option -RRB- takes the form of a 3GB / 1GB split of the 4GB address space , so kernel virtual addresses start at 0xC0000000 and go to 0xFFFFFFFF .. kernel. kernel ( computing ). 32-bit. 32-bit. x86. x86. The lower 896 MB , from 0xC0000000 to 0xF7FFFFFF , is directly mapped to the kernel physical address space , and the remaining 128 MB , from 0xF8000000 to 0xFFFFFFFF , is used on demand by the kernel to be mapped to high memory .. kernel. kernel ( computing ). When in user mode , translations are only effective for the first region , thus protecting the kernel from user programs , but when in kernel mode , translations are effective for both regions , thus giving the kernel an easy way to refer to the buffers of processes -- it just uses the process ' own mappings .. kernel. kernel ( computing ). user mode. user mode. programs. computer program. kernel mode. kernel mode. buffers. data buffer. However , if the kernel needs to refer to physical memory for which a userspace translation has not already been provided , it has only 1GB -LRB- for example -RRB- of virtual memory to use .. physical memory. computer memory. kernel. kernel ( computing ). On computers with a lot of physical memory , this can mean that there exists memory that the kernel can not refer to directly -- this is called high memory .. physical memory. computer memory. kernel. kernel ( computing ). When the kernel wishes to address high memory , it creates a mapping on the fly and destroys the mapping when done , which incurs a performance penalty .. kernel. kernel ( computing )