diff options
| author |  Peter Zijlstra <peterz@infradead.org>
| 2020-03-10 18:43:35 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org>
| 2020-03-25 18:28:28 +0100 |
| commit | 530389968739883a61192767e1c215653ba4ba2b (patch) | |
| tree | d2963d5d64e6c16f6d72ef84053fc34dda57db35 /tools/objtool | |
| parent | objtool: Add a statistics mode (diff) | |
| download | linux-530389968739883a61192767e1c215653ba4ba2b.tar.gz linux-530389968739883a61192767e1c215653ba4ba2b.tar.bz2 linux-530389968739883a61192767e1c215653ba4ba2b.zip | |
objtool: Optimize find_section_by_index()
In order to avoid a linear search (over 20k entries), add an
section_hash to the elf object.
This reduces objtool on vmlinux.o from a few minutes to around 45
seconds.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200324160924.381249993@infradead.org
Diffstat (limited to 'tools/objtool')
| -rw-r--r-- | tools/objtool/elf.c | 13 | ||||
| -rw-r--r-- | tools/objtool/elf.h | 2 |
2 files changed, 10 insertions, 5 deletions
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index ff293064b469..900771365ae3 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -38,7 +38,7 @@ static struct section *find_section_by_index(struct elf *elf, { struct section *sec; - list_for_each_entry(sec, &elf->sections, list) + hash_for_each_possible(elf->section_hash, sec, hash, idx) if (sec->idx == idx) return sec; @@ -166,8 +166,6 @@ static int read_sections(struct elf *elf) INIT_LIST_HEAD(&sec->rela_list); hash_init(sec->rela_hash); - list_add_tail(&sec->list, &elf->sections); - s = elf_getscn(elf->elf, i); if (!s) { WARN_ELF("elf_getscn"); @@ -201,6 +199,9 @@ static int read_sections(struct elf *elf) } } sec->len = sec->sh.sh_size; + + list_add_tail(&sec->list, &elf->sections); + hash_add(elf->section_hash, &sec->hash, sec->idx); } if (stats) @@ -439,6 +440,7 @@ struct elf *elf_read(const char *name, int flags) memset(elf, 0, sizeof(*elf)); hash_init(elf->symbol_hash); + hash_init(elf->section_hash); INIT_LIST_HEAD(&elf->sections); elf->fd = open(name, flags); @@ -501,8 +503,6 @@ struct section *elf_create_section(struct elf *elf, const char *name, INIT_LIST_HEAD(&sec->rela_list); hash_init(sec->rela_hash); - list_add_tail(&sec->list, &elf->sections); - s = elf_newscn(elf->elf); if (!s) { WARN_ELF("elf_newscn"); @@ -579,6 +579,9 @@ struct section *elf_create_section(struct elf *elf, const char *name, shstrtab->len += strlen(name) + 1; shstrtab->changed = true; + list_add_tail(&sec->list, &elf->sections); + hash_add(elf->section_hash, &sec->hash, sec->idx); + return sec; } diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h index 12229801b13f..8c272eb515c8 100644 --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -25,6 +25,7 @@ struct section { struct list_head list; + struct hlist_node hash; GElf_Shdr sh; struct list_head symbol_list; struct list_head rela_list; @@ -71,6 +72,7 @@ struct elf { char *name; struct list_head sections; DECLARE_HASHTABLE(symbol_hash, 20); + DECLARE_HASHTABLE(section_hash, 16); }; |