diff options
Diffstat (limited to 'lib/radix-tree.c')
| -rw-r--r-- | lib/radix-tree.c | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index eaea14b8f2ca..7b9f8515033e 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -70,6 +70,14 @@ static struct kmem_cache *radix_tree_node_cachep; #define IDR_PRELOAD_SIZE (IDR_MAX_PATH * 2 - 1) /* + * The IDA is even shorter since it uses a bitmap at the last level. + */ +#define IDA_INDEX_BITS (8 * sizeof(int) - 1 - ilog2(IDA_BITMAP_BITS)) +#define IDA_MAX_PATH (DIV_ROUND_UP(IDA_INDEX_BITS, \ + RADIX_TREE_MAP_SHIFT)) +#define IDA_PRELOAD_SIZE (IDA_MAX_PATH * 2 - 1) + +/* * Per-cpu pool of preloaded nodes */ struct radix_tree_preload { @@ -346,9 +354,8 @@ static void dump_ida_node(void *entry, unsigned long index) static void ida_dump(struct ida *ida) { struct radix_tree_root *root = &ida->ida_rt; - pr_debug("ida: %p %p free %d bitmap %p\n", ida, root->rnode, - root->gfp_mask >> ROOT_TAG_SHIFT, - ida->free_bitmap); + pr_debug("ida: %p node %p free %d\n", ida, root->rnode, + root->gfp_mask >> ROOT_TAG_SHIFT); dump_ida_node(root->rnode, 0); } #endif @@ -2080,6 +2087,36 @@ void idr_preload(gfp_t gfp_mask) } EXPORT_SYMBOL(idr_preload); +/** + * ida_pre_get - reserve resources for ida allocation + * @ida: ida handle + * @gfp: memory allocation flags + * + * This function should be called before calling ida_get_new_above(). If it + * is unable to allocate memory, it will return %0. On success, it returns %1. + */ +int ida_pre_get(struct ida *ida, gfp_t gfp) +{ + __radix_tree_preload(gfp, IDA_PRELOAD_SIZE); + /* + * The IDA API has no preload_end() equivalent. Instead, + * ida_get_new() can return -EAGAIN, prompting the caller + * to return to the ida_pre_get() step. + */ + preempt_enable(); + + if (!this_cpu_read(ida_bitmap)) { + struct ida_bitmap *bitmap = kmalloc(sizeof(*bitmap), gfp); + if (!bitmap) + return 0; + bitmap = this_cpu_cmpxchg(ida_bitmap, NULL, bitmap); + kfree(bitmap); + } + + return 1; +} +EXPORT_SYMBOL(ida_pre_get); + void **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, int end) { @@ -2219,6 +2256,8 @@ static int radix_tree_cpu_dead(unsigned int cpu) kmem_cache_free(radix_tree_node_cachep, node); rtp->nr--; } + kfree(per_cpu(ida_bitmap, cpu)); + per_cpu(ida_bitmap, cpu) = NULL; return 0; } |