diff options
| author | Paul Mackerras <paulus@samba.org> | 2008-06-18 15:29:12 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-07-01 11:27:57 +1000 |
| commit | 3a8247cc2c856930f34eafce33f6a039227ee175 (patch) | |
| tree | aa8599cdf09893f1150a2bc137878d8b8a661780 /arch/powerpc/platforms/Kconfig.cputype | |
| parent | e952e6c4d6635b36c212c056a9427bd93460178c (diff) | |
powerpc: Only demote individual slices rather than whole process
At present, if we have a kernel with a 64kB page size, and some
process maps something that has to be mapped with 4kB pages (such as a
cache-inhibited mapping on POWER5+, or the eHCA infiniband queue-pair
pages), we change the process to use 4kB pages everywhere. This hurts
the performance of HPC programs that access eHCA from userspace.
With this patch, the kernel will only demote the slice(s) containing
the eHCA or cache-inhibited mappings, leaving the remaining slices
able to use 64kB hardware pages.
This also changes the slice_get_unmapped_area code so that it is
willing to place a 64k-page mapping into (or across) a 4k-page slice
if there is no better alternative, i.e. if the program specified
MAP_FIXED or if there is not sufficient space available in slices that
are either empty or already have 64k-page mappings in them.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/Kconfig.cputype')
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 1a1ccfbb9232..c66b8ed7e7d9 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -187,7 +187,7 @@ config PPC_STD_MMU_32 config PPC_MM_SLICES bool - default y if HUGETLB_PAGE + default y if HUGETLB_PAGE || PPC_64K_PAGES default n config VIRT_CPU_ACCOUNTING |