[PATCH 2/2] [-mm only] mm/shuffle: Default enable all shuffling

From: Dan Williams
Date: Wed Feb 06 2019 - 02:24:56 EST


Per Andrew's request arrange for all memory allocation shuffling code to
be enabled by default.

The page_alloc.shuffle command line parameter can still be used to
disable shuffling at boot, but the kernel will default enable the
shuffling if the command line option is not specified.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
init/Kconfig | 4 ++--
mm/shuffle.c | 4 ++--
mm/shuffle.h | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index cfa199f3e9be..12557e12be4c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1697,7 +1697,7 @@ config SLAB_MERGE_DEFAULT
command line.

config SLAB_FREELIST_RANDOM
- default n
+ default y
depends on SLAB || SLUB
bool "SLAB freelist randomization"
help
@@ -1716,7 +1716,7 @@ config SLAB_FREELIST_HARDENED

config SHUFFLE_PAGE_ALLOCATOR
bool "Page allocator randomization"
- default SLAB_FREELIST_RANDOM && ACPI_NUMA
+ default y
help
Randomization of the page allocator improves the average
utilization of a direct-mapped memory-side-cache. See section
diff --git a/mm/shuffle.c b/mm/shuffle.c
index 3ce12481b1dc..a979b48be469 100644
--- a/mm/shuffle.c
+++ b/mm/shuffle.c
@@ -9,8 +9,8 @@
#include "internal.h"
#include "shuffle.h"

-DEFINE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
-static unsigned long shuffle_state __ro_after_init;
+DEFINE_STATIC_KEY_TRUE(page_alloc_shuffle_key);
+static unsigned long shuffle_state __ro_after_init = 1 << SHUFFLE_ENABLE;

/*
* Depending on the architecture, module parameter parsing may run
diff --git a/mm/shuffle.h b/mm/shuffle.h
index fc1e327ae22d..466a5620e0aa 100644
--- a/mm/shuffle.h
+++ b/mm/shuffle.h
@@ -19,7 +19,7 @@ enum mm_shuffle_ctl {
#define SHUFFLE_ORDER (MAX_ORDER-1)

#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
-DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
+DECLARE_STATIC_KEY_TRUE(page_alloc_shuffle_key);
extern void page_alloc_shuffle(enum mm_shuffle_ctl ctl);
extern void __shuffle_free_memory(pg_data_t *pgdat);
static inline void shuffle_free_memory(pg_data_t *pgdat)