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

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Date:   Thu,  9 Nov 2023 15:59:47 -0800
From:   Namhyung Kim <namhyung@...nel.org>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
Cc:     Ian Rogers <irogers@...gle.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Ingo Molnar <mingo@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-perf-users@...r.kernel.org,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Stephane Eranian <eranian@...gle.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        linux-trace-devel@...r.kernel.org, linux-toolchains@...r.kernel.org
Subject: [PATCH 28/52] perf annotate-data: Parse 'lock' prefix from llvm-objdump

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@...nel.org>
---
 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