diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-02-09 18:24:37 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-02-09 18:24:41 +0100 |
| commit | 6252d702c5311ce916caf75ed82e5c8245171c92 (patch) | |
| tree | 3490f27b5f888ff2c1ec915d4e7201000f37a771 /arch/s390/mm/init.c | |
| parent | 5a216a20837c5f5fa1ca4b8ae8991ffd96b08e6f (diff) | |
[S390] dynamic page tables.
Add support for different number of page table levels dependent
on the highest address used for a process. This will cause a 31 bit
process to use a two level page table instead of the four level page
table that is the default after the pud has been introduced. Likewise
a normal 64 bit process will use three levels instead of four. Only
if a process runs out of the 4 tera bytes which can be addressed with
a three level page table the fourth level is dynamically added. Then
the process can use up to 8 peta byte.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/init.c')
| -rw-r--r-- | arch/s390/mm/init.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 248a71010700..8053245fe259 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -112,8 +112,9 @@ void __init paging_init(void) init_mm.pgd = swapper_pg_dir; S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK; #ifdef CONFIG_64BIT - S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; - pgd_type = _REGION2_ENTRY_EMPTY; + /* A three level page table (4TB) is enough for the kernel space. */ + S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; + pgd_type = _REGION3_ENTRY_EMPTY; #else S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH; pgd_type = _SEGMENT_ENTRY_EMPTY; |