Commit 57578c2e authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Linus Torvalds
Browse files

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: default avatarMatthew Wilcox <willy@linux.intel.com>
Reviewed-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6c4bd68a

lib/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -362,6 +362,9 @@ config INTERVAL_TREE 


	  for more information.



config RADIX_TREE_MULTIORDER

	bool



config ASSOCIATIVE_ARRAY

	bool

	help

lib/radix-tree.c

+18 −8
Original line number Diff line number Diff line
@@ -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--;

mm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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.

tools/testing/radix-tree/linux/kernel.h

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 


#include "../../include/linux/compiler.h"



#define CONFIG_RADIX_TREE_MULTIORDER

#define CONFIG_SHMEM

#define CONFIG_SWAP

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