smp/cpumask: Make CONFIG_CPUMASK_OFFSTACK=y usable without debug dependency

When CONFIG_CPUMASK_OFFSTACK was added in 2008, it was dependent upon
CONFIG_DEBUG_PER_CPU_MAPS being enabled, or an architecture could
select it.

The debug dependency adds additional overhead that isn't required
for operation of the feature and which is undesirable for distro
kernels. CONFIG_CPUMASK_OFFSTACK=y is needed to increase the
CONFIG_NR_CPUS value beyond 512 on x86.

So drop the current dependency, its only real dependency is CONFIG_SMP=y.

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131111140815.GB20328@hansolo.jdub.homelinux.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/lib/Kconfig b/lib/Kconfig
index b3c8be0da17f8472429ad79787c76d42fa62eb02..50b47cde8b49f0f6850e44702d0ee6d159a33e3f 100644 (file)
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -342,7 +342,8 @@ config CHECK_SIGNATURE
        bool
 
 config CPUMASK_OFFSTACK
-       bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
+       bool "Force CPU masks off stack"
+       depends on SMP
        help
          Use dynamic allocation for cpumask_var_t, instead of putting
          them on the stack.  This is a bit more expensive, but avoids