Messages in this thread Patch in this message | | | From | Nikolay Borisov <> | Subject | [PATCH] objtool: Cache number of return sites recorded | Date | Tue, 15 Aug 2023 13:35:09 +0300 |
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On an allyesconfig currently the kernels emits 454324. No point in making around half a million iterations just to count them. Simply increment a counter at the time of creation of each site.
Quick measurements shows a meager 200ms improvement when running objtool --rethunk --prefix=64 --no-unreachable --stats --link
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> --- tools/objtool/check.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8936a05f0e5a..bb71c5d8859f 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -33,6 +33,7 @@ static struct cfi_init_state initial_func_cfi; static struct cfi_state init_cfi; static struct cfi_state func_cfi; static struct cfi_state force_undefined_cfi; +static unsigned long nr_rethunk_sites; struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset) @@ -802,15 +803,12 @@ static int create_return_sites_sections(struct objtool_file *file) return 0; } - idx = 0; - list_for_each_entry(insn, &file->return_thunk_list, call_node) - idx++; - - if (!idx) + if (!nr_rethunk_sites) return 0; sec = elf_create_section_pair(file->elf, ".return_sites", - sizeof(int), idx, idx); + sizeof(int), nr_rethunk_sites, + nr_rethunk_sites); if (!sec) return -1; @@ -1473,8 +1471,10 @@ static void add_return_call(struct objtool_file *file, struct instruction *insn, insn->type = INSN_RETURN; insn->retpoline_safe = true; - if (add) + if (add) { list_add_tail(&insn->call_node, &file->return_thunk_list); + nr_rethunk_sites++; + } } static bool is_first_func_insn(struct objtool_file *file, -- 2.34.1
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