From 3a319a2476d27e0b6c3cac3ebf6e3d0b665a06e5 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Thu, 7 Mar 2024 22:32:06 -0500 Subject: [PATCH] lib/generic-radix-tree.c: Make nodes more reasonably sized this code originally used the page allocator directly, but most code shouldn't do that - PAGE_SIZE varies with architecture, and slab is faster. 4k is also on the large side for typical usage, 512 bytes is a better choice for typical usage that might be somewhat sparse. Signed-off-by: Kent Overstreet --- include/linux/generic-radix-tree.h | 29 ++++++++++++++----------- lib/generic-radix-tree.c | 35 ++++++++++-------------------- 2 files changed, 28 insertions(+), 36 deletions(-) diff --git a/include/linux/generic-radix-tree.h b/include/linux/generic-radix-tree.h index 847413164738..f3512fddf3d7 100644 --- a/include/linux/generic-radix-tree.h +++ b/include/linux/generic-radix-tree.h @@ -5,7 +5,7 @@ * DOC: Generic radix trees/sparse arrays * * Very simple and minimalistic, supporting arbitrary size entries up to - * PAGE_SIZE. + * GENRADIX_NODE_SIZE. * * A genradix is defined with the type it will store, like so: * @@ -45,12 +45,15 @@ struct genradix_root; +#define GENRADIX_NODE_SHIFT 9 +#define GENRADIX_NODE_SIZE (1U << GENRADIX_NODE_SHIFT) + struct __genradix { struct genradix_root *root; }; /* - * NOTE: currently, sizeof(_type) must not be larger than PAGE_SIZE: + * NOTE: currently, sizeof(_type) must not be larger than GENRADIX_NODE_SIZE: */ #define __GENRADIX_INITIALIZER \ @@ -101,14 +104,14 @@ void __genradix_free(struct __genradix *); static inline size_t __idx_to_offset(size_t idx, size_t obj_size) { if (__builtin_constant_p(obj_size)) - BUILD_BUG_ON(obj_size > PAGE_SIZE); + BUILD_BUG_ON(obj_size > GENRADIX_NODE_SIZE); else - BUG_ON(obj_size > PAGE_SIZE); + BUG_ON(obj_size > GENRADIX_NODE_SIZE); if (!is_power_of_2(obj_size)) { - size_t objs_per_page = PAGE_SIZE / obj_size; + size_t objs_per_page = GENRADIX_NODE_SIZE / obj_size; - return (idx / objs_per_page) * PAGE_SIZE + + return (idx / objs_per_page) * GENRADIX_NODE_SIZE + (idx % objs_per_page) * obj_size; } else { return idx * obj_size; @@ -118,9 +121,9 @@ static inline size_t __idx_to_offset(size_t idx, size_t obj_size) #define __genradix_cast(_radix) (typeof((_radix)->type[0]) *) #define __genradix_obj_size(_radix) sizeof((_radix)->type[0]) #define __genradix_objs_per_page(_radix) \ - (PAGE_SIZE / sizeof((_radix)->type[0])) + (GENRADIX_NODE_SIZE / sizeof((_radix)->type[0])) #define __genradix_page_remainder(_radix) \ - (PAGE_SIZE % sizeof((_radix)->type[0])) + (GENRADIX_NODE_SIZE % sizeof((_radix)->type[0])) #define __genradix_idx_to_offset(_radix, _idx) \ __idx_to_offset(_idx, __genradix_obj_size(_radix)) @@ -217,8 +220,8 @@ static inline void __genradix_iter_advance(struct genradix_iter *iter, iter->offset += obj_size; if (!is_power_of_2(obj_size) && - (iter->offset & (PAGE_SIZE - 1)) + obj_size > PAGE_SIZE) - iter->offset = round_up(iter->offset, PAGE_SIZE); + (iter->offset & (GENRADIX_NODE_SIZE - 1)) + obj_size > GENRADIX_NODE_SIZE) + iter->offset = round_up(iter->offset, GENRADIX_NODE_SIZE); iter->pos++; } @@ -235,8 +238,8 @@ static inline void __genradix_iter_rewind(struct genradix_iter *iter, return; } - if ((iter->offset & (PAGE_SIZE - 1)) == 0) - iter->offset -= PAGE_SIZE % obj_size; + if ((iter->offset & (GENRADIX_NODE_SIZE - 1)) == 0) + iter->offset -= GENRADIX_NODE_SIZE % obj_size; iter->offset -= obj_size; iter->pos--; @@ -263,7 +266,7 @@ static inline void __genradix_iter_rewind(struct genradix_iter *iter, genradix_for_each_from(_radix, _iter, _p, 0) #define genradix_last_pos(_radix) \ - (SIZE_MAX / PAGE_SIZE * __genradix_objs_per_page(_radix) - 1) + (SIZE_MAX / GENRADIX_NODE_SIZE * __genradix_objs_per_page(_radix) - 1) /** * genradix_for_each_reverse - iterate over entry in a genradix, reverse order diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c index 41f1bcdc4488..aaefb9b678c8 100644 --- a/lib/generic-radix-tree.c +++ b/lib/generic-radix-tree.c @@ -5,7 +5,7 @@ #include #include -#define GENRADIX_ARY (PAGE_SIZE / sizeof(struct genradix_node *)) +#define GENRADIX_ARY (GENRADIX_NODE_SIZE / sizeof(struct genradix_node *)) #define GENRADIX_ARY_SHIFT ilog2(GENRADIX_ARY) struct genradix_node { @@ -14,13 +14,13 @@ struct genradix_node { struct genradix_node *children[GENRADIX_ARY]; /* Leaf: */ - u8 data[PAGE_SIZE]; + u8 data[GENRADIX_NODE_SIZE]; }; }; static inline int genradix_depth_shift(unsigned depth) { - return PAGE_SHIFT + GENRADIX_ARY_SHIFT * depth; + return GENRADIX_NODE_SHIFT + GENRADIX_ARY_SHIFT * depth; } /* @@ -33,7 +33,7 @@ static inline size_t genradix_depth_size(unsigned depth) /* depth that's needed for a genradix that can address up to ULONG_MAX: */ #define GENRADIX_MAX_DEPTH \ - DIV_ROUND_UP(BITS_PER_LONG - PAGE_SHIFT, GENRADIX_ARY_SHIFT) + DIV_ROUND_UP(BITS_PER_LONG - GENRADIX_NODE_SHIFT, GENRADIX_ARY_SHIFT) #define GENRADIX_DEPTH_MASK \ ((unsigned long) (roundup_pow_of_two(GENRADIX_MAX_DEPTH + 1) - 1)) @@ -79,23 +79,12 @@ EXPORT_SYMBOL(__genradix_ptr); static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask) { - struct genradix_node *node; - - node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO); - - /* - * We're using pages (not slab allocations) directly for kernel data - * structures, so we need to explicitly inform kmemleak of them in order - * to avoid false positive memory leak reports. - */ - kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask); - return node; + return kzalloc(GENRADIX_NODE_SIZE, gfp_mask); } static inline void genradix_free_node(struct genradix_node *node) { - kmemleak_free(node); - free_page((unsigned long)node); + kfree(node); } /* @@ -200,7 +189,7 @@ restart: i++; iter->offset = round_down(iter->offset + objs_per_ptr, objs_per_ptr); - iter->pos = (iter->offset >> PAGE_SHIFT) * + iter->pos = (iter->offset >> GENRADIX_NODE_SHIFT) * objs_per_page; if (i == GENRADIX_ARY) goto restart; @@ -209,7 +198,7 @@ restart: n = n->children[i]; } - return &n->data[iter->offset & (PAGE_SIZE - 1)]; + return &n->data[iter->offset & (GENRADIX_NODE_SIZE - 1)]; } EXPORT_SYMBOL(__genradix_iter_peek); @@ -235,7 +224,7 @@ restart: if (ilog2(iter->offset) >= genradix_depth_shift(level)) { iter->offset = genradix_depth_size(level); - iter->pos = (iter->offset >> PAGE_SHIFT) * objs_per_page; + iter->pos = (iter->offset >> GENRADIX_NODE_SHIFT) * objs_per_page; iter->offset -= obj_size_plus_page_remainder; iter->pos--; @@ -251,7 +240,7 @@ restart: size_t objs_per_ptr = genradix_depth_size(level); iter->offset = round_down(iter->offset, objs_per_ptr); - iter->pos = (iter->offset >> PAGE_SHIFT) * objs_per_page; + iter->pos = (iter->offset >> GENRADIX_NODE_SHIFT) * objs_per_page; if (!iter->offset) return NULL; @@ -267,7 +256,7 @@ restart: n = n->children[i]; } - return &n->data[iter->offset & (PAGE_SIZE - 1)]; + return &n->data[iter->offset & (GENRADIX_NODE_SIZE - 1)]; } EXPORT_SYMBOL(__genradix_iter_peek_prev); @@ -289,7 +278,7 @@ int __genradix_prealloc(struct __genradix *radix, size_t size, { size_t offset; - for (offset = 0; offset < size; offset += PAGE_SIZE) + for (offset = 0; offset < size; offset += GENRADIX_NODE_SIZE) if (!__genradix_ptr_alloc(radix, offset, gfp_mask)) return -ENOMEM;