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

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Date:   Tue, 05 Feb 2019 23:12:15 -0800
From:   Dan Williams <dan.j.williams@...el.com>
To:     akpm@...ux-foundation.org
Cc:     linux-mm@...ck.org, keescook@...omium.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] [-mm only] mm/shuffle: Default enable all shuffling

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@...el.com>
---
 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)