Adds config option LOCKLESS_PAGE_TABLE_WALK_TRACKING to make possible
enabling tracking lockless pagetable walks directly from kernel config.
Signed-off-by: Leonardo Bras <leona...@linux.ibm.com>
---
mm/Kconfig | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/mm/Kconfig b/mm/Kconfig
index a5dae9a7eb51..00f487a0122f 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -736,4 +736,15 @@ config ARCH_HAS_PTE_SPECIAL
config ARCH_HAS_HUGEPD
bool
+config LOCKLESS_PAGE_TABLE_WALK_TRACKING
+ bool "Track (and optimize) lockless page table walks"
+ default n
+
+ help
+ Maintain a reference count of active lockless page table
+ walkers. This adds 4 bytes to struct mm size, and two atomic
+ operations to calls such as get_user_pages_fast(). Some
+ architectures can optimize lockless page table operations if
+ this is enabled.
+
endmenu
--
2.20.1
