2 files changed, 19 insertions, 2 deletions

diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index 2e19fd7ffe35..9b0d04dd2a61 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -380,6 +380,9 @@ include::itrace.txt[]
         Set the maximum number of program blocks to print with brstackasm for
         each sample.
 
+--reltime::
+        Print time stamps relative to trace start.
+
 --per-event-dump::
         Create per event files with a "perf.data.EVENT.dump" name instead of
         printing to stdout, useful, for instance, for generating flamegraphs.
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 2f93d60c5a17..61cfd8f70989 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -53,6 +53,8 @@
 
 static char const               *script_name;
 static char const               *generate_script_lang;
+static bool                     reltime;
+static u64                      initial_time;
 static bool                     debug_mode;
 static u64                      last_timestamp;
 static u64                      nr_unordered;
@@ -686,7 +688,13 @@ static int perf_sample__fprintf_start(struct perf_sample *sample,
         }
 
         if (PRINT_FIELD(TIME)) {
-                nsecs = sample->time;
+                u64 t = sample->time;
+                if (reltime) {
+                        if (!initial_time)
+                                initial_time = sample->time;
+                        t = sample->time - initial_time;
+                }
+                nsecs = t;
                 secs = nsecs / NSEC_PER_SEC;
                 nsecs -= secs * NSEC_PER_SEC;
 
@@ -694,7 +702,7 @@ static int perf_sample__fprintf_start(struct perf_sample *sample,
                         printed += fprintf(fp, "%5lu.%09llu: ", secs, nsecs);
                 else {
                         char sample_time[32];
-                        timestamp__scnprintf_usec(sample->time, sample_time, sizeof(sample_time));
+                        timestamp__scnprintf_usec(t, sample_time, sizeof(sample_time));
                         printed += fprintf(fp, "%12s: ", sample_time);
                 }
         }
@@ -3413,6 +3421,7 @@ int cmd_script(int argc, const char **argv)
                      "Set the maximum stack depth when parsing the callchain, "
                      "anything beyond the specified depth will be ignored. "
                      "Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)),
+        OPT_BOOLEAN(0, "reltime", &reltime, "Show time stamps relative to start"),
         OPT_BOOLEAN('I', "show-info", &show_full_info,
                     "display extended information from perf.data file"),
         OPT_BOOLEAN('\0', "show-kernel-path", &symbol_conf.show_kernel_path,
@@ -3487,6 +3496,11 @@ int cmd_script(int argc, const char **argv)
                 }
         }
 
+        if (script.time_str && reltime) {
+                fprintf(stderr, "Don't combine --reltime with --time\n");
+                return -1;
+        }
+
         if (itrace_synth_opts.callchain &&
             itrace_synth_opts.callchain_sz > scripting_max_stack)
                 scripting_max_stack = itrace_synth_opts.callchain_sz;