The following commit has been merged into the objtool/core branch of tip:
Commit-ID: 02b54001066364aee72bc4c802b42a96c6e0dc1f
Gitweb: https://git.kernel.org/tip/02b54001066364aee72bc4c802b42a96c6e0dc1f
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Tue, 30 May 2023 10:21:11 -07:00
Committer: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Wed, 07 Jun 2023 10:03:25 -07:00
objtool: Shrink elf hash nodes
Instead of using hlist for the 'struct elf' hashes, use a custom
single-linked list scheme.
With allyesconfig + CONFIG_DEBUG_INFO:
- Before: peak heap memory consumption: 36.89G
- After: peak heap memory consumption: 35.12G
Link: https://lore.kernel.org/r/6e8cd305ed22e743c30d6e72cfdc1be20fb94cd4.1685464332.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/elf.c | 52 +++++++++++++++++++++++-----
tools/objtool/include/objtool/elf.h | 24 +++++++------
2 files changed, 58 insertions(+), 18 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 4b0de0e..04038b1 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -32,16 +32,52 @@ static inline u32 str_hash(const char *str)
#define __elf_table(name) (elf->name##_hash)
#define __elf_bits(name) (elf->name##_bits)
-#define elf_hash_add(name, node, key) \
- hlist_add_head(node, &__elf_table(name)[hash_min(key, __elf_bits(name))])
+#define __elf_table_entry(name, key) \
+ __elf_table(name)[hash_min(key, __elf_bits(name))]
+
+#define elf_hash_add(name, node, key) \
+({ \
+ struct elf_hash_node *__node = node; \
+ __node->next = __elf_table_entry(name, key); \
+ __elf_table_entry(name, key) = __node; \
+})
+
+static inline void __elf_hash_del(struct elf_hash_node *node,
+ struct elf_hash_node **head)
+{
+ struct elf_hash_node *cur, *prev;
-#define elf_hash_for_each_possible(name, obj, member, key) \
- hlist_for_each_entry(obj, &__elf_table(name)[hash_min(key, __elf_bits(name))], member)
+ if (node == *head) {
+ *head = node->next;
+ return;
+ }
+
+ for (prev = NULL, cur = *head; cur; prev = cur, cur = cur->next) {
+ if (cur == node) {
+ prev->next = cur->next;
+ break;
+ }
+ }
+}
+
+#define elf_hash_del(name, node, key) \
+ __elf_hash_del(node, &__elf_table_entry(name, key))
+
+#define elf_list_entry(ptr, type, member) \
+({ \
+ typeof(ptr) __ptr = (ptr); \
+ __ptr ? container_of(__ptr, type, member) : NULL; \
+})
+
+#define elf_hash_for_each_possible(name, obj, member, key) \
+ for (obj = elf_list_entry(__elf_table_entry(name, key), typeof(*obj), member); \
+ obj; \
+ obj = elf_list_entry(obj->member.next, typeof(*(obj)), member))
#define elf_alloc_hash(name, size) \
({ \
__elf_bits(name) = max(10, ilog2(size)); \
- __elf_table(name) = mmap(NULL, sizeof(struct hlist_head) << __elf_bits(name), \
+ __elf_table(name) = mmap(NULL, sizeof(struct elf_hash_node *) << __elf_bits(name), \
PROT_READ|PROT_WRITE, \
MAP_PRIVATE|MAP_ANON, -1, 0); \
if (__elf_table(name) == (void *)-1L) { \
@@ -713,10 +749,10 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym)
first_non_local = symtab->sh.sh_info;
old = find_symbol_by_index(elf, first_non_local);
if (old) {
- old->idx = new_idx;
- hlist_del(&old->hash);
- elf_hash_add(symbol, &old->hash, old->idx);
+ elf_hash_del(symbol, &old->hash, old->idx);
+ elf_hash_add(symbol, &old->hash, new_idx);
+ old->idx = new_idx;
if (elf_update_symbol(elf, symtab, symtab_shndx, old)) {
WARN("elf_update_symbol move");
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index 7b808ac..03a9040 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -26,10 +26,14 @@
#define ELF_C_READ_MMAP ELF_C_READ
#endif
+struct elf_hash_node {
+ struct elf_hash_node *next;
+};
+
struct section {
struct list_head list;
- struct hlist_node hash;
- struct hlist_node name_hash;
+ struct elf_hash_node hash;
+ struct elf_hash_node name_hash;
GElf_Shdr sh;
struct rb_root_cached symbol_tree;
struct list_head symbol_list;
@@ -45,8 +49,8 @@ struct section {
struct symbol {
struct list_head list;
struct rb_node node;
- struct hlist_node hash;
- struct hlist_node name_hash;
+ struct elf_hash_node hash;
+ struct elf_hash_node name_hash;
GElf_Sym sym;
struct section *sec;
char *name;
@@ -67,7 +71,7 @@ struct symbol {
};
struct reloc {
- struct hlist_node hash;
+ struct elf_hash_node hash;
union {
GElf_Rela rela;
GElf_Rel rel;
@@ -93,11 +97,11 @@ struct elf {
int section_name_bits;
int reloc_bits;
- struct hlist_head *symbol_hash;
- struct hlist_head *symbol_name_hash;
- struct hlist_head *section_hash;
- struct hlist_head *section_name_hash;
- struct hlist_head *reloc_hash;
+ struct elf_hash_node **symbol_hash;
+ struct elf_hash_node **symbol_name_hash;
+ struct elf_hash_node **section_hash;
+ struct elf_hash_node **section_name_hash;
+ struct elf_hash_node **reloc_hash;
struct section *section_data;
struct symbol *symbol_data;
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