>Does anyone know how to change the TLB size? Once you wade through all of the smart-ass replies let me mention the following.
While the "size" of the TLB measured in number of TLB-entries is cast in silicon, nearly all modern CPU architectures (including the amd64/x86_64) have scheme for increasing the effective capacity of the TLB measured as the total amount of virtual address space that can be mapped. This is because modern TLB designs allow TLB entries to map varying size windows of virtual address space. The problem here is one of OS software. The size of the window mapped by a TLB entry is intimately related to the software's page size. The Linux kernel is just now beginning to add support for page sizes larger than 4K. This is turn ripples back into file system design, free space management, etc. Think pages sizes of 64KB or 1MB. IBM has announced PPC support for 1GB TLB mappings! Such architectural features are designed to support VERY large systems with lots of memory working with VERY large datasets. Anyway, it is going to be a while before such support is available from a conservative release like Gentoo. /john -- [email protected] mailing list
