perf script: Support relative time
When comparing time stamps in 'perf script' traces it can be annoying to
work with the full perf time stamps.
Add a --reltime option that displays time stamps relative to the trace
start to make it easier to read the traces.
Note: not currently supported for --time. Report an error in this
case.
Before:
% perf script
swapper 0 [000] 245402.891216: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms])
swapper 0 [000] 245402.891223: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms])
swapper 0 [000] 245402.891227: 5 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms])
swapper 0 [000] 245402.891231: 41 cycles:ppp: ffffffffa0068816 native_write_msr+0x6 ([kernel.kallsyms])
swapper 0 [000] 245402.891235: 355 cycles:ppp: ffffffffa000dd51 intel_bts_enable_local+0x21 ([kernel.kallsyms])
swapper 0 [000] 245402.891239: 3084 cycles:ppp: ffffffffa0a0150a end_repeat_nmi+0x48 ([kernel.kallsyms])
After:
% perf script --reltime
swapper 0 [000] 0.000000: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms])
swapper 0 [000] 0.000006: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms])
swapper 0 [000] 0.000010: 5 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms])
swapper 0 [000] 0.000014: 41 cycles:ppp: ffffffffa0068816 native_write_msr+0x6 ([kernel.kallsyms])
swapper 0 [000] 0.000018: 355 cycles:ppp: ffffffffa000dd51 intel_bts_enable_local+0x21 ([kernel.kallsyms])
swapper 0 [000] 0.000022: 3084 cycles:ppp: ffffffffa0a0150a end_repeat_nmi+0x48 ([kernel.kallsyms])
Committer notes:
Do not use 'time' as the name of a variable, as this breaks the build on
older glibcs:
cc1: warnings being treated as errors
builtin-script.c: In function 'perf_sample__fprintf_start':
builtin-script.c:691: warning: declaration of 'time' shadows a global declaration
/usr/include/time.h:187: warning: shadowed declaration is here
Signed-off-by: Andi Kleen <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
LPU-Reference: [email protected]
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 2f93d60..61cfd8f 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;
