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Message-ID: <20190523204222.3998365-8-andriin@fb.com>
Date: Thu, 23 May 2019 13:42:17 -0700
From: Andrii Nakryiko <andriin@...com>
To: <andrii.nakryiko@...il.com>, <netdev@...r.kernel.org>,
<bpf@...r.kernel.org>, <ast@...com>, <daniel@...earbox.net>,
<kernel-team@...com>
CC: Andrii Nakryiko <andriin@...com>
Subject: [PATCH v2 bpf-next 07/12] libbpf: switch btf_dedup() to hashmap for dedup table
Utilize libbpf's hashmap as a multimap fof dedup_table implementation.
Signed-off-by: Andrii Nakryiko <andriin@...com>
---
tools/lib/bpf/btf.c | 201 +++++++++++++++++++-------------------------
1 file changed, 85 insertions(+), 116 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 6139550810a1..b2478e98c367 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -14,6 +14,7 @@
#include "bpf.h"
#include "libbpf.h"
#include "libbpf_internal.h"
+#include "hashmap.h"
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
@@ -1293,16 +1294,9 @@ int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
return err;
}
-#define BTF_DEDUP_TABLE_DEFAULT_SIZE (1 << 14)
-#define BTF_DEDUP_TABLE_MAX_SIZE_LOG 31
#define BTF_UNPROCESSED_ID ((__u32)-1)
#define BTF_IN_PROGRESS_ID ((__u32)-2)
-struct btf_dedup_node {
- struct btf_dedup_node *next;
- __u32 type_id;
-};
-
struct btf_dedup {
/* .BTF section to be deduped in-place */
struct btf *btf;
@@ -1318,7 +1312,7 @@ struct btf_dedup {
* candidates, which is fine because we rely on subsequent
* btf_xxx_equal() checks to authoritatively verify type equality.
*/
- struct btf_dedup_node **dedup_table;
+ struct hashmap *dedup_table;
/* Canonical types map */
__u32 *map;
/* Hypothetical mapping, used during type graph equivalence checks */
@@ -1343,30 +1337,18 @@ struct btf_str_ptrs {
__u32 cap;
};
-static inline __u32 hash_combine(__u32 h, __u32 value)
+static long hash_combine(long h, long value)
{
-/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
-#define GOLDEN_RATIO_PRIME 0x9e370001UL
- return h * 37 + value * GOLDEN_RATIO_PRIME;
-#undef GOLDEN_RATIO_PRIME
+ return h * 31 + value;
}
-#define for_each_dedup_cand(d, hash, node) \
- for (node = d->dedup_table[hash & (d->opts.dedup_table_size - 1)]; \
- node; \
- node = node->next)
+#define for_each_dedup_cand(d, node, hash) \
+ hashmap__for_each_key_entry(d->dedup_table, node, (void *)hash)
-static int btf_dedup_table_add(struct btf_dedup *d, __u32 hash, __u32 type_id)
+static int btf_dedup_table_add(struct btf_dedup *d, long hash, __u32 type_id)
{
- struct btf_dedup_node *node = malloc(sizeof(struct btf_dedup_node));
- int bucket = hash & (d->opts.dedup_table_size - 1);
-
- if (!node)
- return -ENOMEM;
- node->type_id = type_id;
- node->next = d->dedup_table[bucket];
- d->dedup_table[bucket] = node;
- return 0;
+ return hashmap__append(d->dedup_table,
+ (void *)hash, (void *)(long)type_id);
}
static int btf_dedup_hypot_map_add(struct btf_dedup *d,
@@ -1395,36 +1377,10 @@ static void btf_dedup_clear_hypot_map(struct btf_dedup *d)
d->hypot_cnt = 0;
}
-static void btf_dedup_table_free(struct btf_dedup *d)
-{
- struct btf_dedup_node *head, *tmp;
- int i;
-
- if (!d->dedup_table)
- return;
-
- for (i = 0; i < d->opts.dedup_table_size; i++) {
- while (d->dedup_table[i]) {
- tmp = d->dedup_table[i];
- d->dedup_table[i] = tmp->next;
- free(tmp);
- }
-
- head = d->dedup_table[i];
- while (head) {
- tmp = head;
- head = head->next;
- free(tmp);
- }
- }
-
- free(d->dedup_table);
- d->dedup_table = NULL;
-}
-
static void btf_dedup_free(struct btf_dedup *d)
{
- btf_dedup_table_free(d);
+ hashmap__free(d->dedup_table);
+ d->dedup_table = NULL;
free(d->map);
d->map = NULL;
@@ -1438,40 +1394,43 @@ static void btf_dedup_free(struct btf_dedup *d)
free(d);
}
-/* Find closest power of two >= to size, capped at 2^max_size_log */
-static __u32 roundup_pow2_max(__u32 size, int max_size_log)
+static size_t btf_dedup_identity_hash_fn(const void *key, void *ctx)
{
- int i;
+ return (size_t)key;
+}
- for (i = 0; i < max_size_log && (1U << i) < size; i++)
- ;
- return 1U << i;
+static size_t btf_dedup_collision_hash_fn(const void *key, void *ctx)
+{
+ return 0;
}
+static bool btf_dedup_equal_fn(const void *k1, const void *k2, void *ctx)
+{
+ return k1 == k2;
+}
static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
const struct btf_dedup_opts *opts)
{
struct btf_dedup *d = calloc(1, sizeof(struct btf_dedup));
+ hashmap_hash_fn hash_fn = btf_dedup_identity_hash_fn;
int i, err = 0;
- __u32 sz;
if (!d)
return ERR_PTR(-ENOMEM);
d->opts.dont_resolve_fwds = opts && opts->dont_resolve_fwds;
- sz = opts && opts->dedup_table_size ? opts->dedup_table_size
- : BTF_DEDUP_TABLE_DEFAULT_SIZE;
- sz = roundup_pow2_max(sz, BTF_DEDUP_TABLE_MAX_SIZE_LOG);
- d->opts.dedup_table_size = sz;
+ /* dedup_table_size is now used only to force collisions in tests */
+ if (opts && opts->dedup_table_size == 1)
+ hash_fn = btf_dedup_collision_hash_fn;
d->btf = btf;
d->btf_ext = btf_ext;
- d->dedup_table = calloc(d->opts.dedup_table_size,
- sizeof(struct btf_dedup_node *));
- if (!d->dedup_table) {
- err = -ENOMEM;
+ d->dedup_table = hashmap__new(hash_fn, btf_dedup_equal_fn, NULL);
+ if (IS_ERR(d->dedup_table)) {
+ err = PTR_ERR(d->dedup_table);
+ d->dedup_table = NULL;
goto done;
}
@@ -1790,9 +1749,9 @@ static int btf_dedup_strings(struct btf_dedup *d)
return err;
}
-static __u32 btf_hash_common(struct btf_type *t)
+static long btf_hash_common(struct btf_type *t)
{
- __u32 h;
+ long h;
h = hash_combine(0, t->name_off);
h = hash_combine(h, t->info);
@@ -1808,10 +1767,10 @@ static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2)
}
/* Calculate type signature hash of INT. */
-static __u32 btf_hash_int(struct btf_type *t)
+static long btf_hash_int(struct btf_type *t)
{
__u32 info = *(__u32 *)(t + 1);
- __u32 h;
+ long h;
h = btf_hash_common(t);
h = hash_combine(h, info);
@@ -1831,9 +1790,9 @@ static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2)
}
/* Calculate type signature hash of ENUM. */
-static __u32 btf_hash_enum(struct btf_type *t)
+static long btf_hash_enum(struct btf_type *t)
{
- __u32 h;
+ long h;
/* don't hash vlen and enum members to support enum fwd resolving */
h = hash_combine(0, t->name_off);
@@ -1885,11 +1844,11 @@ static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2)
* as referenced type IDs equivalence is established separately during type
* graph equivalence check algorithm.
*/
-static __u32 btf_hash_struct(struct btf_type *t)
+static long btf_hash_struct(struct btf_type *t)
{
struct btf_member *member = (struct btf_member *)(t + 1);
__u32 vlen = BTF_INFO_VLEN(t->info);
- __u32 h = btf_hash_common(t);
+ long h = btf_hash_common(t);
int i;
for (i = 0; i < vlen; i++) {
@@ -1932,10 +1891,10 @@ static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2)
* under assumption that they were already resolved to canonical type IDs and
* are not going to change.
*/
-static __u32 btf_hash_array(struct btf_type *t)
+static long btf_hash_array(struct btf_type *t)
{
struct btf_array *info = (struct btf_array *)(t + 1);
- __u32 h = btf_hash_common(t);
+ long h = btf_hash_common(t);
h = hash_combine(h, info->type);
h = hash_combine(h, info->index_type);
@@ -1986,11 +1945,11 @@ static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2)
* under assumption that they were already resolved to canonical type IDs and
* are not going to change.
*/
-static inline __u32 btf_hash_fnproto(struct btf_type *t)
+static long btf_hash_fnproto(struct btf_type *t)
{
struct btf_param *member = (struct btf_param *)(t + 1);
__u16 vlen = BTF_INFO_VLEN(t->info);
- __u32 h = btf_hash_common(t);
+ long h = btf_hash_common(t);
int i;
for (i = 0; i < vlen; i++) {
@@ -2008,7 +1967,7 @@ static inline __u32 btf_hash_fnproto(struct btf_type *t)
* This function is called during reference types deduplication to compare
* FUNC_PROTO to potential canonical representative.
*/
-static inline bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2)
+static bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2)
{
struct btf_param *m1, *m2;
__u16 vlen;
@@ -2034,7 +1993,7 @@ static inline bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2)
* IDs. This check is performed during type graph equivalence check and
* referenced types equivalence is checked separately.
*/
-static inline bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
+static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
{
struct btf_param *m1, *m2;
__u16 vlen;
@@ -2065,11 +2024,12 @@ static inline bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
{
struct btf_type *t = d->btf->types[type_id];
+ struct hashmap_entry *hash_entry;
struct btf_type *cand;
- struct btf_dedup_node *cand_node;
/* if we don't find equivalent type, then we are canonical */
__u32 new_id = type_id;
- __u32 h;
+ __u32 cand_id;
+ long h;
switch (BTF_INFO_KIND(t->info)) {
case BTF_KIND_CONST:
@@ -2088,10 +2048,11 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
case BTF_KIND_INT:
h = btf_hash_int(t);
- for_each_dedup_cand(d, h, cand_node) {
- cand = d->btf->types[cand_node->type_id];
+ for_each_dedup_cand(d, hash_entry, h) {
+ cand_id = (__u32)(long)hash_entry->value;
+ cand = d->btf->types[cand_id];
if (btf_equal_int(t, cand)) {
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
}
@@ -2099,10 +2060,11 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
case BTF_KIND_ENUM:
h = btf_hash_enum(t);
- for_each_dedup_cand(d, h, cand_node) {
- cand = d->btf->types[cand_node->type_id];
+ for_each_dedup_cand(d, hash_entry, h) {
+ cand_id = (__u32)(long)hash_entry->value;
+ cand = d->btf->types[cand_id];
if (btf_equal_enum(t, cand)) {
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
if (d->opts.dont_resolve_fwds)
@@ -2110,21 +2072,22 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
if (btf_compat_enum(t, cand)) {
if (btf_is_enum_fwd(t)) {
/* resolve fwd to full enum */
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
/* resolve canonical enum fwd to full enum */
- d->map[cand_node->type_id] = type_id;
+ d->map[cand_id] = type_id;
}
}
break;
case BTF_KIND_FWD:
h = btf_hash_common(t);
- for_each_dedup_cand(d, h, cand_node) {
- cand = d->btf->types[cand_node->type_id];
+ for_each_dedup_cand(d, hash_entry, h) {
+ cand_id = (__u32)(long)hash_entry->value;
+ cand = d->btf->types[cand_id];
if (btf_equal_common(t, cand)) {
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
}
@@ -2525,12 +2488,12 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d)
*/
static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
{
- struct btf_dedup_node *cand_node;
struct btf_type *cand_type, *t;
+ struct hashmap_entry *hash_entry;
/* if we don't find equivalent type, then we are canonical */
__u32 new_id = type_id;
__u16 kind;
- __u32 h;
+ long h;
/* already deduped or is in process of deduping (loop detected) */
if (d->map[type_id] <= BTF_MAX_NR_TYPES)
@@ -2543,7 +2506,8 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
return 0;
h = btf_hash_struct(t);
- for_each_dedup_cand(d, h, cand_node) {
+ for_each_dedup_cand(d, hash_entry, h) {
+ __u32 cand_id = (__u32)(long)hash_entry->value;
int eq;
/*
@@ -2556,17 +2520,17 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
* creating a loop (FWD -> STRUCT and STRUCT -> FWD), because
* FWD and compatible STRUCT/UNION are considered equivalent.
*/
- cand_type = d->btf->types[cand_node->type_id];
+ cand_type = d->btf->types[cand_id];
if (!btf_shallow_equal_struct(t, cand_type))
continue;
btf_dedup_clear_hypot_map(d);
- eq = btf_dedup_is_equiv(d, type_id, cand_node->type_id);
+ eq = btf_dedup_is_equiv(d, type_id, cand_id);
if (eq < 0)
return eq;
if (!eq)
continue;
- new_id = cand_node->type_id;
+ new_id = cand_id;
btf_dedup_merge_hypot_map(d);
break;
}
@@ -2616,12 +2580,12 @@ static int btf_dedup_struct_types(struct btf_dedup *d)
*/
static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
{
- struct btf_dedup_node *cand_node;
+ struct hashmap_entry *hash_entry;
+ __u32 new_id = type_id, cand_id;
struct btf_type *t, *cand;
/* if we don't find equivalent type, then we are representative type */
- __u32 new_id = type_id;
int ref_type_id;
- __u32 h;
+ long h;
if (d->map[type_id] == BTF_IN_PROGRESS_ID)
return -ELOOP;
@@ -2644,10 +2608,11 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
t->type = ref_type_id;
h = btf_hash_common(t);
- for_each_dedup_cand(d, h, cand_node) {
- cand = d->btf->types[cand_node->type_id];
+ for_each_dedup_cand(d, hash_entry, h) {
+ cand_id = (__u32)(long)hash_entry->value;
+ cand = d->btf->types[cand_id];
if (btf_equal_common(t, cand)) {
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
}
@@ -2667,10 +2632,11 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
info->index_type = ref_type_id;
h = btf_hash_array(t);
- for_each_dedup_cand(d, h, cand_node) {
- cand = d->btf->types[cand_node->type_id];
+ for_each_dedup_cand(d, hash_entry, h) {
+ cand_id = (__u32)(long)hash_entry->value;
+ cand = d->btf->types[cand_id];
if (btf_equal_array(t, cand)) {
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
}
@@ -2698,10 +2664,11 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
}
h = btf_hash_fnproto(t);
- for_each_dedup_cand(d, h, cand_node) {
- cand = d->btf->types[cand_node->type_id];
+ for_each_dedup_cand(d, hash_entry, h) {
+ cand_id = (__u32)(long)hash_entry->value;
+ cand = d->btf->types[cand_id];
if (btf_equal_fnproto(t, cand)) {
- new_id = cand_node->type_id;
+ new_id = cand_id;
break;
}
}
@@ -2728,7 +2695,9 @@ static int btf_dedup_ref_types(struct btf_dedup *d)
if (err < 0)
return err;
}
- btf_dedup_table_free(d);
+ /* we won't need d->dedup_table anymore */
+ hashmap__free(d->dedup_table);
+ d->dedup_table = NULL;
return 0;
}
--
2.17.1
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