From e18b890bb0881bbab6f4f1a6cd20d9c60d66b003 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 6 Dec 2006 20:33:20 -0800 Subject: [PATCH] slab: remove kmem_cache_t Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/radix-tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib/radix-tree.c') diff --git a/lib/radix-tree.c b/lib/radix-tree.c index aa9bfd0bdbd..9eb25955019 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -63,7 +63,7 @@ static unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH] __read_mostly; /* * Radix tree node cache. */ -static kmem_cache_t *radix_tree_node_cachep; +static struct kmem_cache *radix_tree_node_cachep; /* * Per-cpu pool of preloaded nodes @@ -846,7 +846,7 @@ int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag) EXPORT_SYMBOL(radix_tree_tagged); static void -radix_tree_node_ctor(void *node, kmem_cache_t *cachep, unsigned long flags) +radix_tree_node_ctor(void *node, struct kmem_cache *cachep, unsigned long flags) { memset(node, 0, sizeof(struct radix_tree_node)); } -- cgit v1.2.3-70-g09d2 From 7cf9c2c76c1a17b32f2da85b50cd4fe468ed44b5 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 6 Dec 2006 20:33:44 -0800 Subject: [PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin Cc: "Paul E. McKenney" Signed-off-by: Lee Schermerhorn Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/radix-tree.h | 101 ++++++++++++++ lib/radix-tree.c | 327 +++++++++++++++++++++++++++++++-------------- mm/migrate.c | 19 ++- 3 files changed, 340 insertions(+), 107 deletions(-) (limited to 'lib/radix-tree.c') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index cbfa1153742..0deb842541a 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -1,6 +1,7 @@ /* * Copyright (C) 2001 Momchil Velikov * Portions Copyright (C) 2001 Christoph Hellwig + * Copyright (C) 2006 Nick Piggin * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as @@ -21,6 +22,35 @@ #include #include +#include +#include + +/* + * A direct pointer (root->rnode pointing directly to a data item, + * rather than another radix_tree_node) is signalled by the low bit + * set in the root->rnode pointer. + * + * In this case root->height is also NULL, but the direct pointer tests are + * needed for RCU lookups when root->height is unreliable. + */ +#define RADIX_TREE_DIRECT_PTR 1 + +static inline void *radix_tree_ptr_to_direct(void *ptr) +{ + return (void *)((unsigned long)ptr | RADIX_TREE_DIRECT_PTR); +} + +static inline void *radix_tree_direct_to_ptr(void *ptr) +{ + return (void *)((unsigned long)ptr & ~RADIX_TREE_DIRECT_PTR); +} + +static inline int radix_tree_is_direct_ptr(void *ptr) +{ + return (int)((unsigned long)ptr & RADIX_TREE_DIRECT_PTR); +} + +/*** radix-tree API starts here ***/ #define RADIX_TREE_MAX_TAGS 2 @@ -47,6 +77,77 @@ do { \ (root)->rnode = NULL; \ } while (0) +/** + * Radix-tree synchronization + * + * The radix-tree API requires that users provide all synchronisation (with + * specific exceptions, noted below). + * + * Synchronization of access to the data items being stored in the tree, and + * management of their lifetimes must be completely managed by API users. + * + * For API usage, in general, + * - any function _modifying_ the the tree or tags (inserting or deleting + * items, setting or clearing tags must exclude other modifications, and + * exclude any functions reading the tree. + * - any function _reading_ the the tree or tags (looking up items or tags, + * gang lookups) must exclude modifications to the tree, but may occur + * concurrently with other readers. + * + * The notable exceptions to this rule are the following functions: + * radix_tree_lookup + * radix_tree_tag_get + * radix_tree_gang_lookup + * radix_tree_gang_lookup_tag + * radix_tree_tagged + * + * The first 4 functions are able to be called locklessly, using RCU. The + * caller must ensure calls to these functions are made within rcu_read_lock() + * regions. Other readers (lock-free or otherwise) and modifications may be + * running concurrently. + * + * It is still required that the caller manage the synchronization and lifetimes + * of the items. So if RCU lock-free lookups are used, typically this would mean + * that the items have their own locks, or are amenable to lock-free access; and + * that the items are freed by RCU (or only freed after having been deleted from + * the radix tree *and* a synchronize_rcu() grace period). + * + * (Note, rcu_assign_pointer and rcu_dereference are not needed to control + * access to data items when inserting into or looking up from the radix tree) + * + * radix_tree_tagged is able to be called without locking or RCU. + */ + +/** + * radix_tree_deref_slot - dereference a slot + * @pslot: pointer to slot, returned by radix_tree_lookup_slot + * Returns: item that was stored in that slot with any direct pointer flag + * removed. + * + * For use with radix_tree_lookup_slot(). Caller must hold tree at least read + * locked across slot lookup and dereference. More likely, will be used with + * radix_tree_replace_slot(), as well, so caller will hold tree write locked. + */ +static inline void *radix_tree_deref_slot(void **pslot) +{ + return radix_tree_direct_to_ptr(*pslot); +} +/** + * radix_tree_replace_slot - replace item in a slot + * @pslot: pointer to slot, returned by radix_tree_lookup_slot + * @item: new item to store in the slot. + * + * For use with radix_tree_lookup_slot(). Caller must hold tree write locked + * across slot lookup and replacement. + */ +static inline void radix_tree_replace_slot(void **pslot, void *item) +{ + BUG_ON(radix_tree_is_direct_ptr(item)); + rcu_assign_pointer(*pslot, + (void *)((unsigned long)item | + ((unsigned long)*pslot & RADIX_TREE_DIRECT_PTR))); +} + int radix_tree_insert(struct radix_tree_root *, unsigned long, void *); void *radix_tree_lookup(struct radix_tree_root *, unsigned long); void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long); diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 9eb25955019..e2cefabb5aa 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -2,6 +2,7 @@ * Copyright (C) 2001 Momchil Velikov * Portions Copyright (C) 2001 Christoph Hellwig * Copyright (C) 2005 SGI, Christoph Lameter + * Copyright (C) 2006 Nick Piggin * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as @@ -30,6 +31,7 @@ #include #include #include +#include #ifdef __KERNEL__ @@ -45,7 +47,9 @@ ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG) struct radix_tree_node { + unsigned int height; /* Height from the bottom */ unsigned int count; + struct rcu_head rcu_head; void *slots[RADIX_TREE_MAP_SIZE]; unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS]; }; @@ -100,13 +104,21 @@ radix_tree_node_alloc(struct radix_tree_root *root) rtp->nr--; } } + BUG_ON(radix_tree_is_direct_ptr(ret)); return ret; } +static void radix_tree_node_rcu_free(struct rcu_head *head) +{ + struct radix_tree_node *node = + container_of(head, struct radix_tree_node, rcu_head); + kmem_cache_free(radix_tree_node_cachep, node); +} + static inline void radix_tree_node_free(struct radix_tree_node *node) { - kmem_cache_free(radix_tree_node_cachep, node); + call_rcu(&node->rcu_head, radix_tree_node_rcu_free); } /* @@ -222,11 +234,12 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) } do { + unsigned int newheight; if (!(node = radix_tree_node_alloc(root))) return -ENOMEM; /* Increase the height. */ - node->slots[0] = root->rnode; + node->slots[0] = radix_tree_direct_to_ptr(root->rnode); /* Propagate the aggregated tag info into the new root */ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { @@ -234,9 +247,11 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) tag_set(node, tag, 0); } + newheight = root->height+1; + node->height = newheight; node->count = 1; - root->rnode = node; - root->height++; + rcu_assign_pointer(root->rnode, node); + root->height = newheight; } while (height > root->height); out: return 0; @@ -258,6 +273,8 @@ int radix_tree_insert(struct radix_tree_root *root, int offset; int error; + BUG_ON(radix_tree_is_direct_ptr(item)); + /* Make sure the tree is high enough. */ if (index > radix_tree_maxindex(root->height)) { error = radix_tree_extend(root, index); @@ -275,11 +292,12 @@ int radix_tree_insert(struct radix_tree_root *root, /* Have to add a child node. */ if (!(slot = radix_tree_node_alloc(root))) return -ENOMEM; + slot->height = height; if (node) { - node->slots[offset] = slot; + rcu_assign_pointer(node->slots[offset], slot); node->count++; } else - root->rnode = slot; + rcu_assign_pointer(root->rnode, slot); } /* Go a level down */ @@ -295,11 +313,11 @@ int radix_tree_insert(struct radix_tree_root *root, if (node) { node->count++; - node->slots[offset] = item; + rcu_assign_pointer(node->slots[offset], item); BUG_ON(tag_get(node, 0, offset)); BUG_ON(tag_get(node, 1, offset)); } else { - root->rnode = item; + rcu_assign_pointer(root->rnode, radix_tree_ptr_to_direct(item)); BUG_ON(root_tag_get(root, 0)); BUG_ON(root_tag_get(root, 1)); } @@ -308,49 +326,54 @@ int radix_tree_insert(struct radix_tree_root *root, } EXPORT_SYMBOL(radix_tree_insert); -static inline void **__lookup_slot(struct radix_tree_root *root, - unsigned long index) +/** + * radix_tree_lookup_slot - lookup a slot in a radix tree + * @root: radix tree root + * @index: index key + * + * Returns: the slot corresponding to the position @index in the + * radix tree @root. This is useful for update-if-exists operations. + * + * This function cannot be called under rcu_read_lock, it must be + * excluded from writers, as must the returned slot for subsequent + * use by radix_tree_deref_slot() and radix_tree_replace slot. + * Caller must hold tree write locked across slot lookup and + * replace. + */ +void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index) { unsigned int height, shift; - struct radix_tree_node **slot; - - height = root->height; + struct radix_tree_node *node, **slot; - if (index > radix_tree_maxindex(height)) + node = root->rnode; + if (node == NULL) return NULL; - if (height == 0 && root->rnode) + if (radix_tree_is_direct_ptr(node)) { + if (index > 0) + return NULL; return (void **)&root->rnode; + } + + height = node->height; + if (index > radix_tree_maxindex(height)) + return NULL; shift = (height-1) * RADIX_TREE_MAP_SHIFT; - slot = &root->rnode; - while (height > 0) { - if (*slot == NULL) + do { + slot = (struct radix_tree_node **) + (node->slots + ((index>>shift) & RADIX_TREE_MAP_MASK)); + node = *slot; + if (node == NULL) return NULL; - slot = (struct radix_tree_node **) - ((*slot)->slots + - ((index >> shift) & RADIX_TREE_MAP_MASK)); shift -= RADIX_TREE_MAP_SHIFT; height--; - } + } while (height > 0); return (void **)slot; } - -/** - * radix_tree_lookup_slot - lookup a slot in a radix tree - * @root: radix tree root - * @index: index key - * - * Lookup the slot corresponding to the position @index in the radix tree - * @root. This is useful for update-if-exists operations. - */ -void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index) -{ - return __lookup_slot(root, index); -} EXPORT_SYMBOL(radix_tree_lookup_slot); /** @@ -359,13 +382,45 @@ EXPORT_SYMBOL(radix_tree_lookup_slot); * @index: index key * * Lookup the item at the position @index in the radix tree @root. + * + * This function can be called under rcu_read_lock, however the caller + * must manage lifetimes of leaf nodes (eg. RCU may also be used to free + * them safely). No RCU barriers are required to access or modify the + * returned item, however. */ void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index) { - void **slot; + unsigned int height, shift; + struct radix_tree_node *node, **slot; + + node = rcu_dereference(root->rnode); + if (node == NULL) + return NULL; + + if (radix_tree_is_direct_ptr(node)) { + if (index > 0) + return NULL; + return radix_tree_direct_to_ptr(node); + } + + height = node->height; + if (index > radix_tree_maxindex(height)) + return NULL; + + shift = (height-1) * RADIX_TREE_MAP_SHIFT; - slot = __lookup_slot(root, index); - return slot != NULL ? *slot : NULL; + do { + slot = (struct radix_tree_node **) + (node->slots + ((index>>shift) & RADIX_TREE_MAP_MASK)); + node = rcu_dereference(*slot); + if (node == NULL) + return NULL; + + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } while (height > 0); + + return node; } EXPORT_SYMBOL(radix_tree_lookup); @@ -495,27 +550,30 @@ int radix_tree_tag_get(struct radix_tree_root *root, unsigned long index, unsigned int tag) { unsigned int height, shift; - struct radix_tree_node *slot; + struct radix_tree_node *node; int saw_unset_tag = 0; - height = root->height; - if (index > radix_tree_maxindex(height)) - return 0; - /* check the root's tag bit */ if (!root_tag_get(root, tag)) return 0; - if (height == 0) - return 1; + node = rcu_dereference(root->rnode); + if (node == NULL) + return 0; + + if (radix_tree_is_direct_ptr(node)) + return (index == 0); + + height = node->height; + if (index > radix_tree_maxindex(height)) + return 0; shift = (height - 1) * RADIX_TREE_MAP_SHIFT; - slot = root->rnode; for ( ; ; ) { int offset; - if (slot == NULL) + if (node == NULL) return 0; offset = (index >> shift) & RADIX_TREE_MAP_MASK; @@ -524,15 +582,15 @@ int radix_tree_tag_get(struct radix_tree_root *root, * This is just a debug check. Later, we can bale as soon as * we see an unset tag. */ - if (!tag_get(slot, tag, offset)) + if (!tag_get(node, tag, offset)) saw_unset_tag = 1; if (height == 1) { - int ret = tag_get(slot, tag, offset); + int ret = tag_get(node, tag, offset); BUG_ON(ret && saw_unset_tag); return !!ret; } - slot = slot->slots[offset]; + node = rcu_dereference(node->slots[offset]); shift -= RADIX_TREE_MAP_SHIFT; height--; } @@ -541,47 +599,45 @@ EXPORT_SYMBOL(radix_tree_tag_get); #endif static unsigned int -__lookup(struct radix_tree_root *root, void **results, unsigned long index, +__lookup(struct radix_tree_node *slot, void **results, unsigned long index, unsigned int max_items, unsigned long *next_index) { unsigned int nr_found = 0; unsigned int shift, height; - struct radix_tree_node *slot; unsigned long i; - height = root->height; - if (height == 0) { - if (root->rnode && index == 0) - results[nr_found++] = root->rnode; + height = slot->height; + if (height == 0) goto out; - } - shift = (height-1) * RADIX_TREE_MAP_SHIFT; - slot = root->rnode; for ( ; height > 1; height--) { - - for (i = (index >> shift) & RADIX_TREE_MAP_MASK ; - i < RADIX_TREE_MAP_SIZE; i++) { + i = (index >> shift) & RADIX_TREE_MAP_MASK; + for (;;) { if (slot->slots[i] != NULL) break; index &= ~((1UL << shift) - 1); index += 1UL << shift; if (index == 0) goto out; /* 32-bit wraparound */ + i++; + if (i == RADIX_TREE_MAP_SIZE) + goto out; } - if (i == RADIX_TREE_MAP_SIZE) - goto out; shift -= RADIX_TREE_MAP_SHIFT; - slot = slot->slots[i]; + slot = rcu_dereference(slot->slots[i]); + if (slot == NULL) + goto out; } /* Bottom level: grab some items */ for (i = index & RADIX_TREE_MAP_MASK; i < RADIX_TREE_MAP_SIZE; i++) { + struct radix_tree_node *node; index++; - if (slot->slots[i]) { - results[nr_found++] = slot->slots[i]; + node = slot->slots[i]; + if (node) { + results[nr_found++] = rcu_dereference(node); if (nr_found == max_items) goto out; } @@ -603,28 +659,51 @@ out: * *@results. * * The implementation is naive. + * + * Like radix_tree_lookup, radix_tree_gang_lookup may be called under + * rcu_read_lock. In this case, rather than the returned results being + * an atomic snapshot of the tree at a single point in time, the semantics + * of an RCU protected gang lookup are as though multiple radix_tree_lookups + * have been issued in individual locks, and results stored in 'results'. */ unsigned int radix_tree_gang_lookup(struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items) { - const unsigned long max_index = radix_tree_maxindex(root->height); + unsigned long max_index; + struct radix_tree_node *node; unsigned long cur_index = first_index; - unsigned int ret = 0; + unsigned int ret; + + node = rcu_dereference(root->rnode); + if (!node) + return 0; + if (radix_tree_is_direct_ptr(node)) { + if (first_index > 0) + return 0; + node = radix_tree_direct_to_ptr(node); + results[0] = rcu_dereference(node); + return 1; + } + + max_index = radix_tree_maxindex(node->height); + + ret = 0; while (ret < max_items) { unsigned int nr_found; unsigned long next_index; /* Index of next search */ if (cur_index > max_index) break; - nr_found = __lookup(root, results + ret, cur_index, + nr_found = __lookup(node, results + ret, cur_index, max_items - ret, &next_index); ret += nr_found; if (next_index == 0) break; cur_index = next_index; } + return ret; } EXPORT_SYMBOL(radix_tree_gang_lookup); @@ -634,55 +713,64 @@ EXPORT_SYMBOL(radix_tree_gang_lookup); * open-coding the search. */ static unsigned int -__lookup_tag(struct radix_tree_root *root, void **results, unsigned long index, +__lookup_tag(struct radix_tree_node *slot, void **results, unsigned long index, unsigned int max_items, unsigned long *next_index, unsigned int tag) { unsigned int nr_found = 0; - unsigned int shift; - unsigned int height = root->height; - struct radix_tree_node *slot; + unsigned int shift, height; - if (height == 0) { - if (root->rnode && index == 0) - results[nr_found++] = root->rnode; + height = slot->height; + if (height == 0) goto out; - } - - shift = (height - 1) * RADIX_TREE_MAP_SHIFT; - slot = root->rnode; + shift = (height-1) * RADIX_TREE_MAP_SHIFT; - do { - unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK; + while (height > 0) { + unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK ; - for ( ; i < RADIX_TREE_MAP_SIZE; i++) { - if (tag_get(slot, tag, i)) { - BUG_ON(slot->slots[i] == NULL); + for (;;) { + if (tag_get(slot, tag, i)) break; - } index &= ~((1UL << shift) - 1); index += 1UL << shift; if (index == 0) goto out; /* 32-bit wraparound */ + i++; + if (i == RADIX_TREE_MAP_SIZE) + goto out; } - if (i == RADIX_TREE_MAP_SIZE) - goto out; height--; if (height == 0) { /* Bottom level: grab some items */ unsigned long j = index & RADIX_TREE_MAP_MASK; for ( ; j < RADIX_TREE_MAP_SIZE; j++) { + struct radix_tree_node *node; index++; - if (tag_get(slot, tag, j)) { - BUG_ON(slot->slots[j] == NULL); - results[nr_found++] = slot->slots[j]; + if (!tag_get(slot, tag, j)) + continue; + node = slot->slots[j]; + /* + * Even though the tag was found set, we need to + * recheck that we have a non-NULL node, because + * if this lookup is lockless, it may have been + * subsequently deleted. + * + * Similar care must be taken in any place that + * lookup ->slots[x] without a lock (ie. can't + * rely on its value remaining the same). + */ + if (node) { + node = rcu_dereference(node); + results[nr_found++] = node; if (nr_found == max_items) goto out; } } } shift -= RADIX_TREE_MAP_SHIFT; - slot = slot->slots[i]; - } while (height > 0); + slot = rcu_dereference(slot->slots[i]); + if (slot == NULL) + break; + } out: *next_index = index; return nr_found; @@ -706,27 +794,44 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items, unsigned int tag) { - const unsigned long max_index = radix_tree_maxindex(root->height); + struct radix_tree_node *node; + unsigned long max_index; unsigned long cur_index = first_index; - unsigned int ret = 0; + unsigned int ret; /* check the root's tag bit */ if (!root_tag_get(root, tag)) return 0; + node = rcu_dereference(root->rnode); + if (!node) + return 0; + + if (radix_tree_is_direct_ptr(node)) { + if (first_index > 0) + return 0; + node = radix_tree_direct_to_ptr(node); + results[0] = rcu_dereference(node); + return 1; + } + + max_index = radix_tree_maxindex(node->height); + + ret = 0; while (ret < max_items) { unsigned int nr_found; unsigned long next_index; /* Index of next search */ if (cur_index > max_index) break; - nr_found = __lookup_tag(root, results + ret, cur_index, + nr_found = __lookup_tag(node, results + ret, cur_index, max_items - ret, &next_index, tag); ret += nr_found; if (next_index == 0) break; cur_index = next_index; } + return ret; } EXPORT_SYMBOL(radix_tree_gang_lookup_tag); @@ -742,8 +847,19 @@ static inline void radix_tree_shrink(struct radix_tree_root *root) root->rnode->count == 1 && root->rnode->slots[0]) { struct radix_tree_node *to_free = root->rnode; + void *newptr; - root->rnode = to_free->slots[0]; + /* + * We don't need rcu_assign_pointer(), since we are simply + * moving the node from one part of the tree to another. If + * it was safe to dereference the old pointer to it + * (to_free->slots[0]), it will be safe to dereference the new + * one (root->rnode). + */ + newptr = to_free->slots[0]; + if (root->height == 1) + newptr = radix_tree_ptr_to_direct(newptr); + root->rnode = newptr; root->height--; /* must only free zeroed nodes into the slab */ tag_clear(to_free, 0, 0); @@ -767,6 +883,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) { struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; struct radix_tree_node *slot = NULL; + struct radix_tree_node *to_free; unsigned int height, shift; int tag; int offset; @@ -777,6 +894,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) slot = root->rnode; if (height == 0 && root->rnode) { + slot = radix_tree_direct_to_ptr(slot); root_tag_clear_all(root); root->rnode = NULL; goto out; @@ -809,10 +927,17 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) radix_tree_tag_clear(root, index, tag); } + to_free = NULL; /* Now free the nodes we do not need anymore */ while (pathp->node) { pathp->node->slots[pathp->offset] = NULL; pathp->node->count--; + /* + * Queue the node for deferred freeing after the + * last reference to it disappears (set NULL, above). + */ + if (to_free) + radix_tree_node_free(to_free); if (pathp->node->count) { if (pathp->node == root->rnode) @@ -821,13 +946,15 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) } /* Node with zero slots in use so free it */ - radix_tree_node_free(pathp->node); - + to_free = pathp->node; pathp--; + } root_tag_clear_all(root); root->height = 0; root->rnode = NULL; + if (to_free) + radix_tree_node_free(to_free); out: return slot; diff --git a/mm/migrate.c b/mm/migrate.c index b4979d423d2..e9b161bde95 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -294,7 +294,7 @@ out: static int migrate_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page) { - struct page **radix_pointer; + void **pslot; if (!mapping) { /* Anonymous page */ @@ -305,12 +305,11 @@ static int migrate_page_move_mapping(struct address_space *mapping, write_lock_irq(&mapping->tree_lock); - radix_pointer = (struct page **)radix_tree_lookup_slot( - &mapping->page_tree, - page_index(page)); + pslot = radix_tree_lookup_slot(&mapping->page_tree, + page_index(page)); if (page_count(page) != 2 + !!PagePrivate(page) || - *radix_pointer != page) { + (struct page *)radix_tree_deref_slot(pslot) != page) { write_unlock_irq(&mapping->tree_lock); return -EAGAIN; } @@ -318,7 +317,7 @@ static int migrate_page_move_mapping(struct address_space *mapping, /* * Now we know that no one else is looking at the page. */ - get_page(newpage); + get_page(newpage); /* add cache reference */ #ifdef CONFIG_SWAP if (PageSwapCache(page)) { SetPageSwapCache(newpage); @@ -326,8 +325,14 @@ static int migrate_page_move_mapping(struct address_space *mapping, } #endif - *radix_pointer = newpage; + radix_tree_replace_slot(pslot, newpage); + + /* + * Drop cache reference from old page. + * We know this isn't the last reference. + */ __put_page(page); + write_unlock_irq(&mapping->tree_lock); return 0; -- cgit v1.2.3-70-g09d2 From 02316067852187b8bec781bec07410e91af79627 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 6 Dec 2006 20:38:17 -0800 Subject: [PATCH] hotplug CPU: clean up hotcpu_notifier() use There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn, prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus generating compiler warnings of unused symbols, hence forcing people to add #ifdefs. the compiler can skip truly unused functions just fine: text data bss dec hex filename 1624412 728710 3674856 6027978 5bfaca vmlinux.before 1624412 728710 3674856 6027978 5bfaca vmlinux.after [akpm@osdl.org: topology.c fix] Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/cpu/mcheck/therm_throt.c | 2 -- arch/i386/kernel/cpuid.c | 2 -- arch/i386/kernel/microcode.c | 2 -- arch/i386/kernel/msr.c | 2 -- arch/ia64/kernel/palinfo.c | 2 -- arch/ia64/kernel/salinfo.c | 2 -- arch/s390/appldata/appldata_base.c | 2 -- arch/x86_64/kernel/mce.c | 2 -- arch/x86_64/kernel/mce_amd.c | 4 ++-- arch/x86_64/kernel/vsyscall.c | 2 -- block/ll_rw_blk.c | 4 ---- drivers/base/topology.c | 2 -- drivers/cpufreq/cpufreq.c | 2 -- fs/buffer.c | 2 -- include/linux/cpu.h | 6 +++--- kernel/cpuset.c | 4 ---- kernel/profile.c | 3 +-- kernel/sched.c | 3 --- kernel/workqueue.c | 2 -- lib/radix-tree.c | 2 -- mm/page_alloc.c | 4 ---- mm/swap.c | 2 ++ mm/vmscan.c | 2 -- net/core/dev.c | 2 -- net/core/flow.c | 2 -- 25 files changed, 8 insertions(+), 56 deletions(-) (limited to 'lib/radix-tree.c') diff --git a/arch/i386/kernel/cpu/mcheck/therm_throt.c b/arch/i386/kernel/cpu/mcheck/therm_throt.c index bad8b442070..065005c3f16 100644 --- a/arch/i386/kernel/cpu/mcheck/therm_throt.c +++ b/arch/i386/kernel/cpu/mcheck/therm_throt.c @@ -116,7 +116,6 @@ static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev) return sysfs_create_group(&sys_dev->kobj, &thermal_throttle_attr_group); } -#ifdef CONFIG_HOTPLUG_CPU static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev) { return sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group); @@ -153,7 +152,6 @@ static struct notifier_block thermal_throttle_cpu_notifier = { .notifier_call = thermal_throttle_cpu_callback, }; -#endif /* CONFIG_HOTPLUG_CPU */ static __init int thermal_throttle_init_device(void) { diff --git a/arch/i386/kernel/cpuid.c b/arch/i386/kernel/cpuid.c index ab0c327e79d..23b2cc748d4 100644 --- a/arch/i386/kernel/cpuid.c +++ b/arch/i386/kernel/cpuid.c @@ -167,7 +167,6 @@ static int cpuid_device_create(int i) return err; } -#ifdef CONFIG_HOTPLUG_CPU static int cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { unsigned int cpu = (unsigned long)hcpu; @@ -187,7 +186,6 @@ static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier = { .notifier_call = cpuid_class_cpu_callback, }; -#endif /* !CONFIG_HOTPLUG_CPU */ static int __init cpuid_init(void) { diff --git a/arch/i386/kernel/microcode.c b/arch/i386/kernel/microcode.c index 23f5984d065..972346604f9 100644 --- a/arch/i386/kernel/microcode.c +++ b/arch/i386/kernel/microcode.c @@ -703,7 +703,6 @@ static struct sysdev_driver mc_sysdev_driver = { .resume = mc_sysdev_resume, }; -#ifdef CONFIG_HOTPLUG_CPU static __cpuinit int mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu) { @@ -726,7 +725,6 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu) static struct notifier_block mc_cpu_notifier = { .notifier_call = mc_cpu_callback, }; -#endif static int __init microcode_init (void) { diff --git a/arch/i386/kernel/msr.c b/arch/i386/kernel/msr.c index a773f776c9e..7763c67ca28 100644 --- a/arch/i386/kernel/msr.c +++ b/arch/i386/kernel/msr.c @@ -250,7 +250,6 @@ static int msr_device_create(int i) return err; } -#ifdef CONFIG_HOTPLUG_CPU static int msr_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { @@ -271,7 +270,6 @@ static struct notifier_block __cpuinitdata msr_class_cpu_notifier = { .notifier_call = msr_class_cpu_callback, }; -#endif static int __init msr_init(void) { diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c index 0b546e2b36a..c4c10a0b99d 100644 --- a/arch/ia64/kernel/palinfo.c +++ b/arch/ia64/kernel/palinfo.c @@ -952,7 +952,6 @@ remove_palinfo_proc_entries(unsigned int hcpu) } } -#ifdef CONFIG_HOTPLUG_CPU static int palinfo_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { @@ -974,7 +973,6 @@ static struct notifier_block palinfo_cpu_notifier = .notifier_call = palinfo_cpu_callback, .priority = 0, }; -#endif static int __init palinfo_init(void) diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c index e63b8ca5344..fd607ca51a8 100644 --- a/arch/ia64/kernel/salinfo.c +++ b/arch/ia64/kernel/salinfo.c @@ -575,7 +575,6 @@ static struct file_operations salinfo_data_fops = { .write = salinfo_log_write, }; -#ifdef CONFIG_HOTPLUG_CPU static int __devinit salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu) { @@ -620,7 +619,6 @@ static struct notifier_block salinfo_cpu_notifier = .notifier_call = salinfo_cpu_callback, .priority = 0, }; -#endif /* CONFIG_HOTPLUG_CPU */ static int __init salinfo_init(void) diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c index 67d5cf9cba8..b8c23729026 100644 --- a/arch/s390/appldata/appldata_base.c +++ b/arch/s390/appldata/appldata_base.c @@ -561,7 +561,6 @@ appldata_offline_cpu(int cpu) spin_unlock(&appldata_timer_lock); } -#ifdef CONFIG_HOTPLUG_CPU static int __cpuinit appldata_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) @@ -582,7 +581,6 @@ appldata_cpu_notify(struct notifier_block *self, static struct notifier_block appldata_nb = { .notifier_call = appldata_cpu_notify, }; -#endif /* * appldata_init() diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c index c7587fc3901..bc863c464a1 100644 --- a/arch/x86_64/kernel/mce.c +++ b/arch/x86_64/kernel/mce.c @@ -641,7 +641,6 @@ static __cpuinit int mce_create_device(unsigned int cpu) return err; } -#ifdef CONFIG_HOTPLUG_CPU static void mce_remove_device(unsigned int cpu) { int i; @@ -674,7 +673,6 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) static struct notifier_block mce_cpu_notifier = { .notifier_call = mce_cpu_callback, }; -#endif static __init int mce_init_device(void) { diff --git a/arch/x86_64/kernel/mce_amd.c b/arch/x86_64/kernel/mce_amd.c index 883fe747f64..fa09debad4b 100644 --- a/arch/x86_64/kernel/mce_amd.c +++ b/arch/x86_64/kernel/mce_amd.c @@ -551,7 +551,6 @@ out: return err; } -#ifdef CONFIG_HOTPLUG_CPU /* * let's be hotplug friendly. * in case of multiple core processors, the first core always takes ownership @@ -594,12 +593,14 @@ static void threshold_remove_bank(unsigned int cpu, int bank) sprintf(name, "threshold_bank%i", bank); +#ifdef CONFIG_SMP /* sibling symlink */ if (shared_bank[bank] && b->blocks->cpu != cpu) { sysfs_remove_link(&per_cpu(device_mce, cpu).kobj, name); per_cpu(threshold_banks, cpu)[bank] = NULL; return; } +#endif /* remove all sibling symlinks before unregistering */ for_each_cpu_mask(i, b->cpus) { @@ -656,7 +657,6 @@ static int threshold_cpu_callback(struct notifier_block *nfb, static struct notifier_block threshold_cpu_notifier = { .notifier_call = threshold_cpu_callback, }; -#endif /* CONFIG_HOTPLUG_CPU */ static __init int threshold_init_device(void) { diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c index 630036c06c7..3785e495473 100644 --- a/arch/x86_64/kernel/vsyscall.c +++ b/arch/x86_64/kernel/vsyscall.c @@ -275,7 +275,6 @@ static void __cpuinit cpu_vsyscall_init(void *arg) vsyscall_set_cpu(raw_smp_processor_id()); } -#ifdef CONFIG_HOTPLUG_CPU static int __cpuinit cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg) { @@ -284,7 +283,6 @@ cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg) smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 0, 1); return NOTIFY_DONE; } -#endif static void __init map_vsyscall(void) { diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index a4ff3271d4a..31512cd9f3a 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3459,8 +3459,6 @@ static void blk_done_softirq(struct softirq_action *h) } } -#ifdef CONFIG_HOTPLUG_CPU - static int blk_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { @@ -3486,8 +3484,6 @@ static struct notifier_block __devinitdata blk_cpu_notifier = { .notifier_call = blk_cpu_notify, }; -#endif /* CONFIG_HOTPLUG_CPU */ - /** * blk_complete_request - end I/O on a request * @req: the request being processed diff --git a/drivers/base/topology.c b/drivers/base/topology.c index 3d12b85b096..067a9e8bc37 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -108,7 +108,6 @@ static int __cpuinit topology_add_dev(unsigned int cpu) return rc; } -#ifdef CONFIG_HOTPLUG_CPU static void __cpuinit topology_remove_dev(unsigned int cpu) { struct sys_device *sys_dev = get_cpu_sysdev(cpu); @@ -136,7 +135,6 @@ static int __cpuinit topology_cpu_callback(struct notifier_block *nfb, } return rc ? NOTIFY_BAD : NOTIFY_OK; } -#endif static int __cpuinit topology_sysfs_init(void) { diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 7a7c6e6dfe4..47ab42db122 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1537,7 +1537,6 @@ int cpufreq_update_policy(unsigned int cpu) } EXPORT_SYMBOL(cpufreq_update_policy); -#ifdef CONFIG_HOTPLUG_CPU static int cpufreq_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { @@ -1577,7 +1576,6 @@ static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = { .notifier_call = cpufreq_cpu_callback, }; -#endif /* CONFIG_HOTPLUG_CPU */ /********************************************************************* * REGISTER / UNREGISTER CPUFREQ DRIVER * diff --git a/fs/buffer.c b/fs/buffer.c index a8ca0ac2148..517860f2d75 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2972,7 +2972,6 @@ init_buffer_head(void *data, struct kmem_cache *cachep, unsigned long flags) } } -#ifdef CONFIG_HOTPLUG_CPU static void buffer_exit_cpu(int cpu) { int i; @@ -2994,7 +2993,6 @@ static int buffer_cpu_notify(struct notifier_block *self, buffer_exit_cpu((unsigned long)hcpu); return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ void __init buffer_init(void) { diff --git a/include/linux/cpu.h b/include/linux/cpu.h index f02d71bf689..71dc6ba4f73 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -89,9 +89,9 @@ int cpu_down(unsigned int cpu); #define lock_cpu_hotplug() do { } while (0) #define unlock_cpu_hotplug() do { } while (0) #define lock_cpu_hotplug_interruptible() 0 -#define hotcpu_notifier(fn, pri) do { } while (0) -#define register_hotcpu_notifier(nb) do { } while (0) -#define unregister_hotcpu_notifier(nb) do { } while (0) +#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) +#define register_hotcpu_notifier(nb) do { (void)(nb); } while (0) +#define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0) /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ static inline int cpu_is_offline(int cpu) { return 0; } diff --git a/kernel/cpuset.c b/kernel/cpuset.c index bd1e89c4c96..9b62b4c03ad 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2044,7 +2044,6 @@ out: return err; } -#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG) /* * If common_cpu_mem_hotplug_unplug(), below, unplugs any CPUs * or memory nodes, we need to walk over the cpuset hierarchy, @@ -2108,9 +2107,7 @@ static void common_cpu_mem_hotplug_unplug(void) mutex_unlock(&callback_mutex); mutex_unlock(&manage_mutex); } -#endif -#ifdef CONFIG_HOTPLUG_CPU /* * The top_cpuset tracks what CPUs and Memory Nodes are online, * period. This is necessary in order to make cpusets transparent @@ -2127,7 +2124,6 @@ static int cpuset_handle_cpuhp(struct notifier_block *nb, common_cpu_mem_hotplug_unplug(); return 0; } -#endif #ifdef CONFIG_MEMORY_HOTPLUG /* diff --git a/kernel/profile.c b/kernel/profile.c index 04fd84e8cdb..0961d93e1d9 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -319,7 +319,6 @@ out: put_cpu(); } -#ifdef CONFIG_HOTPLUG_CPU static int __devinit profile_cpu_callback(struct notifier_block *info, unsigned long action, void *__cpu) { @@ -372,10 +371,10 @@ static int __devinit profile_cpu_callback(struct notifier_block *info, } return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ #else /* !CONFIG_SMP */ #define profile_flip_buffers() do { } while (0) #define profile_discard_flip_buffers() do { } while (0) +#define profile_cpu_callback NULL void profile_hits(int type, void *__pc, unsigned int nr_hits) { diff --git a/kernel/sched.c b/kernel/sched.c index 75a005ed4ed..c83f531c288 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6740,8 +6740,6 @@ SYSDEV_ATTR(sched_smt_power_savings, 0644, sched_smt_power_savings_show, sched_smt_power_savings_store); #endif - -#ifdef CONFIG_HOTPLUG_CPU /* * Force a reinitialization of the sched domains hierarchy. The domains * and groups cannot be updated in place without racing with the balancing @@ -6774,7 +6772,6 @@ static int update_sched_domains(struct notifier_block *nfb, return NOTIFY_OK; } -#endif void __init sched_init_smp(void) { diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5484d6e045c..c5257316f4b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -655,7 +655,6 @@ int current_is_keventd(void) } -#ifdef CONFIG_HOTPLUG_CPU /* Take the work from this (downed) CPU. */ static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) { @@ -738,7 +737,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, return NOTIFY_OK; } -#endif void init_workqueues(void) { diff --git a/lib/radix-tree.c b/lib/radix-tree.c index e2cefabb5aa..d69ddbe4386 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -996,7 +996,6 @@ static __init void radix_tree_init_maxindex(void) height_to_maxindex[i] = __maxindex(i); } -#ifdef CONFIG_HOTPLUG_CPU static int radix_tree_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) @@ -1016,7 +1015,6 @@ static int radix_tree_callback(struct notifier_block *nfb, } return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ void __init radix_tree_init(void) { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2273952300d..27ec7a1b802 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -701,7 +701,6 @@ void drain_node_pages(int nodeid) } #endif -#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) static void __drain_pages(unsigned int cpu) { unsigned long flags; @@ -723,7 +722,6 @@ static void __drain_pages(unsigned int cpu) } } } -#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_PM @@ -2907,7 +2905,6 @@ void __init free_area_init(unsigned long *zones_size) __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); } -#ifdef CONFIG_HOTPLUG_CPU static int page_alloc_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { @@ -2922,7 +2919,6 @@ static int page_alloc_cpu_notify(struct notifier_block *self, } return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ void __init page_alloc_init(void) { diff --git a/mm/swap.c b/mm/swap.c index 017e72ca9bb..2ed7be39795 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -514,5 +514,7 @@ void __init swap_setup(void) * Right now other parts of the system means that we * _really_ don't want to cluster much more */ +#ifdef CONFIG_HOTPLUG_CPU hotcpu_notifier(cpu_swap_callback, 0); +#endif } diff --git a/mm/vmscan.c b/mm/vmscan.c index f6616e81fac..093f5fe6dd7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1513,7 +1513,6 @@ out: } #endif -#ifdef CONFIG_HOTPLUG_CPU /* It's optimal to keep kswapds on the same CPUs as their memory, but not required for correctness. So if the last cpu in a node goes away, we get changed to run anywhere: as the first one comes back, @@ -1534,7 +1533,6 @@ static int __devinit cpu_callback(struct notifier_block *nfb, } return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ /* * This kswapd start function will be called by init and node-hot-add. diff --git a/net/core/dev.c b/net/core/dev.c index 59d058a3b50..e660cb57e42 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3340,7 +3340,6 @@ void unregister_netdev(struct net_device *dev) EXPORT_SYMBOL(unregister_netdev); -#ifdef CONFIG_HOTPLUG_CPU static int dev_cpu_callback(struct notifier_block *nfb, unsigned long action, void *ocpu) @@ -3384,7 +3383,6 @@ static int dev_cpu_callback(struct notifier_block *nfb, return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_NET_DMA /** diff --git a/net/core/flow.c b/net/core/flow.c index 104c25d00a1..d137f971f97 100644 --- a/net/core/flow.c +++ b/net/core/flow.c @@ -340,7 +340,6 @@ static void __devinit flow_cache_cpu_prepare(int cpu) tasklet_init(tasklet, flow_cache_flush_tasklet, 0); } -#ifdef CONFIG_HOTPLUG_CPU static int flow_cache_cpu(struct notifier_block *nfb, unsigned long action, void *hcpu) @@ -349,7 +348,6 @@ static int flow_cache_cpu(struct notifier_block *nfb, __flow_cache_shrink((unsigned long)hcpu, 0); return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ static int __init flow_cache_init(void) { -- cgit v1.2.3-70-g09d2