Geert Uytterhoeven wrote: > > On Mon, 28 Jan 2002, Phil Thompson wrote: > > - USER_PTRS_PER_PGD is defined as TASK_SIZE/PGDIR_SIZE. However, > > because, TASK_SIZE is actually defined as one less that the maximum task > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > size there is a rounding error that means that USER_PTRS_PER_PGD works > ^^^^ > > out at 511 rather than 512. This means that entries 511 and 1023 of > > swapper_pg_dir don't get initialised. > > > > The corresponding mips64 code has only the first call to pgd_init() and > > each implementation of pgd_init() initialises PTRS_PER_PGD entries, > > where PTRS_PER_PGD is simple defined as 1024. > > > > The attached patch applies the mips64 approach to the mips code. > > > > Should USER_PTRS_PER_PGD be defined as (TASK_SIZE/PGDIR_SIZE) + 1? > > You mean ((TASK_SIZE)+1)/PGDIR_SIZE? > No. It should be +#define USER_PTRS_PER_PGD ((TASK_SIZE-1)/PGDIR_SIZE + 1) Mathmatically, USER_PTRS_PER_PGD=ceil(TASK_SIZE/PGDIR_SIZE) I submitted this patch to Ralf on Jan 03. Ralf, any reason for not applying this? This formula ensures PTRS_PER_PGD is always correct irrespect of the values of TAKS_SIZE and PGDIR_SIZE. See this patch and other pending patches at http://linux.junsun.net/patches/oss.sgi.com/submitted Jun
