[POWERPC] Enable CONFIG_FORCE_MAX_ZONEORDER for all PowerPC, and make selectable

This enables the FORCE_MAX_ZONEORDER Kconfig option for all PowerPC
systems.  Previously, it was enabled only for 64-bit systems.  We also
make the option selectable from the menu, so that the user can specify
different values.  This is useful for 32-bit systems that need to
allocate more than 4MB of physically contiguous memory.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Timur Tabi 2008-03-26 08:35:32 +11:00 committed by Paul Mackerras
parent c5d5d94aa5
commit 6ccf61f94f

View File

@ -211,14 +211,25 @@ source kernel/Kconfig.hz
source kernel/Kconfig.preempt
source "fs/Kconfig.binfmt"
# We optimistically allocate largepages from the VM, so make the limit
# large enough (16MB). This badly named config option is actually
# max order + 1
config FORCE_MAX_ZONEORDER
int
depends on PPC64
int "Maximum zone order"
default "9" if PPC_64K_PAGES
default "13"
default "13" if PPC64
default "11"
help
The kernel memory allocator divides physically contiguous memory
blocks into "zones", where each zone is a power of two number of
pages. This option selects the largest power of two that the kernel
keeps in the memory allocator. If you need to allocate very large
blocks of physically contiguous memory, then you may need to
increase this value.
This config option is actually maximum order plus one. For example,
a value of 11 means that the largest free memory block is 2^10 pages.
The page size is not necessarily 4KB. For example, on 64-bit
systems, 64KB pages can be enabled via CONFIG_PPC_64K_PAGES. Keep
this in mind when choosing a value for this option.
config HUGETLB_PAGE_SIZE_VARIABLE
bool