mm: remove !NUMA condition from PAGEFLAGS_EXTENDED condition set

CONFIG_PAGEFLAGS_EXTENDED disables a trick to conserve pageflags.
This trick is indended to be enabled when the pressure on page flags
is very high.

The previous condition was:

-       depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM

... however, the sparsemem code already has a way to crowd out the
node number from the pageflags, which means that !NUMA actually
doesn't contribute to hard pageflags exhaustion.

This is required for the new PG_uncached flag to not cause pageflags
exhaustion on x86_32 + PAE + SPARSEMEM + !NUMA.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4A9828F4.4040905@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.siddha@intel.com>

diff --git a/mm/Kconfig b/mm/Kconfig
index c948d4c..fe221c7 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -153,7 +153,7 @@ config MEMORY_HOTREMOVE
 #
 config PAGEFLAGS_EXTENDED
        def_bool y
-       depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM
+       depends on 64BIT || SPARSEMEM_VMEMMAP || !SPARSEMEM
 
 # Heavily threaded applications may benefit from splitting the mm-wide
 # page_table_lock, so that faults on different parts of the user address