[PATCH 28/52] perf annotate-data: Parse 'lock' prefix from llvm-objdump

From: Namhyung Kim
Date: Thu Nov 09 2023 - 19:02:43 EST


For the performance reason, I prefer llvm-objdump over GNU's. But I
found that llvm-objdump puts x86 lock prefix in a separate line like
below.

ffffffff81000695: f0 lock
ffffffff81000696: ff 83 54 0b 00 00 incl 2900(%rbx)

This should be parsed properly, but I just changed to find the insn
with next offset for now.

This improves the statistics as it can process more instructions.

Annotate data type stats:
total 294, ok 144 (49.0%), bad 150 (51.0%)
-----------------------------------------------------------
30 : no_sym
35 : no_mem_ops
71 : no_var
6 : no_typeinfo
8 : bad_offset

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/annotate.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 3ac601d70f61..2f325a9cf33a 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -3664,8 +3664,17 @@ static struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip)
notes = symbol__annotation(sym);

list_for_each_entry(dl, &notes->src->source, al.node) {
- if (sym->start + dl->al.offset == ip)
+ if (sym->start + dl->al.offset == ip) {
+ /*
+ * llvm-objdump places "lock" in a separate line and
+ * in that case, we want to get the next line.
+ */
+ if (!strcmp(dl->ins.name, "lock") && *dl->ops.raw == '\0') {
+ ip++;
+ continue;
+ }
return dl;
+ }
}
return NULL;
}
@@ -3757,6 +3766,9 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
if (!op_loc->mem_ref)
continue;

+ /* Recalculate IP since it can be changed due to LOCK prefix */
+ ip = ms->sym->start + dl->al.offset;
+
mem_type = find_data_type(ms, ip, op_loc->reg, op_loc->offset);
if (mem_type)
istat->good++;
--
2.42.0.869.gea05f2083d-goog