From 57578c2ea2cb2e0d362a9212ac83cf90221d4883 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Fri, 20 May 2016 17:01:54 -0700 Subject: [PATCH] raxix-tree: introduce CONFIG_RADIX_TREE_MULTIORDER I've been receiving increasingly concerned notes from 0day about how much my recent changes have been bloating the radix tree. Make it happier by only including multiorder support if CONFIG_TRANSPARENT_HUGEPAGES is set. This is an independent Kconfig option, so other radix tree users can also set it if they have a need. Signed-off-by: Matthew Wilcox Reviewed-by: Ross Zwisler Cc: Konstantin Khlebnikov Cc: Kirill Shutemov Cc: Jan Kara Cc: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig | 3 +++ lib/radix-tree.c | 26 +++++++++++++++++-------- mm/Kconfig | 1 + tools/testing/radix-tree/linux/kernel.h | 1 + 4 files changed, 23 insertions(+), 8 deletions(-) diff --git a/lib/Kconfig b/lib/Kconfig index 61d55bd0ed89..d79909dc01ec 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -362,6 +362,9 @@ config INTERVAL_TREE for more information. +config RADIX_TREE_MULTIORDER + bool + config ASSOCIATIVE_ARRAY bool help diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 1624c4117961..799f341977d0 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -484,6 +484,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, slot = node->slots[offset]; } +#ifdef CONFIG_RADIX_TREE_MULTIORDER /* Insert pointers to the canonical entry */ if ((shift - order) > 0) { int i, n = 1 << (shift - order); @@ -499,6 +500,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, node->count++; } } +#endif if (nodep) *nodep = node; @@ -1469,6 +1471,20 @@ bool __radix_tree_delete_node(struct radix_tree_root *root, return deleted; } +static inline void delete_sibling_entries(struct radix_tree_node *node, + void *ptr, unsigned offset) +{ +#ifdef CONFIG_RADIX_TREE_MULTIORDER + int i; + for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) { + if (node->slots[offset + i] != ptr) + break; + node->slots[offset + i] = NULL; + node->count--; + } +#endif +} + /** * radix_tree_delete_item - delete an item from a radix tree * @root: radix tree root @@ -1484,7 +1500,7 @@ void *radix_tree_delete_item(struct radix_tree_root *root, unsigned long index, void *item) { struct radix_tree_node *node; - unsigned int offset, i; + unsigned int offset; void **slot; void *entry; int tag; @@ -1513,13 +1529,7 @@ void *radix_tree_delete_item(struct radix_tree_root *root, radix_tree_tag_clear(root, index, tag); } - /* Delete any sibling slots pointing to this slot */ - for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) { - if (node->slots[offset + i] != ptr_to_indirect(slot)) - break; - node->slots[offset + i] = NULL; - node->count--; - } + delete_sibling_entries(node, ptr_to_indirect(slot), offset); node->slots[offset] = NULL; node->count--; diff --git a/mm/Kconfig b/mm/Kconfig index 1a6a28ebcb8b..2664c118b5d2 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -404,6 +404,7 @@ config TRANSPARENT_HUGEPAGE bool "Transparent Hugepage Support" depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE select COMPACTION + select RADIX_TREE_MULTIORDER help Transparent Hugepages allows the kernel to use huge pages and huge tlb transparently to the applications whenever possible. diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h index 31fe2c77d7ae..8ea0ed450810 100644 --- a/tools/testing/radix-tree/linux/kernel.h +++ b/tools/testing/radix-tree/linux/kernel.h @@ -9,6 +9,7 @@ #include "../../include/linux/compiler.h" +#define CONFIG_RADIX_TREE_MULTIORDER #define CONFIG_SHMEM #define CONFIG_SWAP