[PATCH] perf: perl scripts now get a backtrace, like the python scripts

From: Dima Kogan
Date: Fri Mar 25 2016 - 15:29:15 EST


Hi.

Currently the python perf scripts get a backtrace, while the perl ones do not.
This patch adds that to the perl scripts as well.

---
.../perf/util/scripting-engines/trace-event-perl.c | 115 +++++++++++++++++++--
1 file changed, 107 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 1bd593b..f048c58 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -31,6 +31,8 @@
#include <perl.h>

#include "../../perf.h"
+#include "../callchain.h"
+#include "../machine.h"
#include "../thread.h"
#include "../event.h"
#include "../trace-event.h"
@@ -244,10 +246,79 @@ static void define_event_symbols(struct event_format *event,
define_event_symbols(event, ev_name, args->next);
}

+static SV *perl_process_callchain(struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct addr_location *al)
+{
+ AV *list;
+
+ list = newAV();
+ if (!list)
+ goto exit;
+
+ if (!symbol_conf.use_callchain || !sample->callchain)
+ goto exit;
+
+ if (thread__resolve_callchain(al->thread, evsel,
+ sample, NULL, NULL,
+ PERF_MAX_STACK_DEPTH) != 0) {
+ pr_err("Failed to resolve callchain. Skipping\n");
+ goto exit;
+ }
+ callchain_cursor_commit(&callchain_cursor);
+
+
+ while (1) {
+ HV *elem;
+ struct callchain_cursor_node *node;
+ node = callchain_cursor_current(&callchain_cursor);
+ if (!node)
+ break;
+
+ elem = newHV();
+ if (!elem)
+ goto exit;
+
+ // mortal?
+ hv_stores(elem, "ip", newSVuv(node->ip));
+
+ if (node->sym) {
+ HV *sym = newHV();
+ if (!sym)
+ goto exit;
+ hv_stores(sym, "start", newSVuv(node->sym->start));
+ hv_stores(sym, "end", newSVuv(node->sym->end));
+ hv_stores(sym, "binding", newSVuv(node->sym->binding));
+ hv_stores(sym, "name", newSVpvn(node->sym->name,
+ node->sym->namelen));
+ hv_stores(elem, "sym", newRV_noinc((SV*)sym));
+ }
+
+ if (node->map) {
+ struct map *map = node->map;
+ const char *dsoname = "[unknown]";
+ if (map && map->dso && (map->dso->name || map->dso->long_name)) {
+ if (symbol_conf.show_kernel_path && map->dso->long_name)
+ dsoname = map->dso->long_name;
+ else if (map->dso->name)
+ dsoname = map->dso->name;
+ }
+ hv_stores(elem, "dso", newSVpv(dsoname,0));
+ }
+
+ callchain_cursor_advance(&callchain_cursor);
+ av_push(list, newRV_noinc((SV*)elem));
+ }
+
+exit:
+ return newRV_noinc((SV*)list);
+}
+
static void perl_process_tracepoint(struct perf_sample *sample,
struct perf_evsel *evsel,
- struct thread *thread)
+ struct addr_location *al)
{
+ struct thread *thread = al->thread;
struct event_format *event = evsel->tp_format;
struct format_field *field;
static char handler[256];
@@ -291,6 +362,7 @@ static void perl_process_tracepoint(struct perf_sample *sample,
XPUSHs(sv_2mortal(newSVuv(ns)));
XPUSHs(sv_2mortal(newSViv(pid)));
XPUSHs(sv_2mortal(newSVpv(comm, 0)));
+ XPUSHs(sv_2mortal(perl_process_callchain(sample, evsel, al)));

/* common fields other than pid can be accessed via xsub fns */

@@ -325,6 +397,7 @@ static void perl_process_tracepoint(struct perf_sample *sample,
XPUSHs(sv_2mortal(newSVuv(nsecs)));
XPUSHs(sv_2mortal(newSViv(pid)));
XPUSHs(sv_2mortal(newSVpv(comm, 0)));
+ XPUSHs(sv_2mortal(perl_process_callchain(sample, evsel, al)));
call_pv("main::trace_unhandled", G_SCALAR);
}
SPAGAIN;
@@ -362,7 +435,7 @@ static void perl_process_event(union perf_event *event,
struct perf_evsel *evsel,
struct addr_location *al)
{
- perl_process_tracepoint(sample, evsel, al->thread);
+ perl_process_tracepoint(sample, evsel, al);
perl_process_event_generic(event, sample, evsel);
}

@@ -486,7 +559,27 @@ static int perl_generate_script(struct pevent *pevent, const char *outfile)
fprintf(ofp, "use Perf::Trace::Util;\n\n");

fprintf(ofp, "sub trace_begin\n{\n\t# optional\n}\n\n");
- fprintf(ofp, "sub trace_end\n{\n\t# optional\n}\n\n");
+ fprintf(ofp, "sub trace_end\n{\n\t# optional\n}\n");
+
+
+ fprintf(ofp, "\n\
+sub print_backtrace\n\
+{\n\
+ my $callchain = shift;\n\
+ for my $node (@$callchain)\n\
+ {\n\
+ if(exists $node->{sym})\n\
+ {\n\
+ printf( \"\\t[\\%%x] \\%%s\\n\", $node->{ip}, $node->{sym}{name});\n\
+ }\n\
+ else\n\
+ {\n\
+ printf( \"\\t[\\%%x]\\n\", $node{ip});\n\
+ }\n\
+ }\n\
+}\n\n\
+");
+

while ((event = trace_find_next_event(pevent, event))) {
fprintf(ofp, "sub %s::%s\n{\n", event->system, event->name);
@@ -498,7 +591,8 @@ static int perl_generate_script(struct pevent *pevent, const char *outfile)
fprintf(ofp, "$common_secs, ");
fprintf(ofp, "$common_nsecs,\n");
fprintf(ofp, "\t $common_pid, ");
- fprintf(ofp, "$common_comm,\n\t ");
+ fprintf(ofp, "$common_comm, ");
+ fprintf(ofp, "$common_callchain,\n\t ");

not_first = 0;
count = 0;
@@ -515,7 +609,7 @@ static int perl_generate_script(struct pevent *pevent, const char *outfile)

fprintf(ofp, "\tprint_header($event_name, $common_cpu, "
"$common_secs, $common_nsecs,\n\t "
- "$common_pid, $common_comm);\n\n");
+ "$common_pid, $common_comm, $common_callchain);\n\n");

fprintf(ofp, "\tprintf(\"");

@@ -577,17 +671,22 @@ static int perl_generate_script(struct pevent *pevent, const char *outfile)
fprintf(ofp, "$%s", f->name);
}

- fprintf(ofp, ");\n");
+ fprintf(ofp, ");\n\n");
+
+ fprintf(ofp, "\tprint_backtrace($common_callchain);\n");
+
fprintf(ofp, "}\n\n");
}

fprintf(ofp, "sub trace_unhandled\n{\n\tmy ($event_name, $context, "
"$common_cpu, $common_secs, $common_nsecs,\n\t "
- "$common_pid, $common_comm) = @_;\n\n");
+ "$common_pid, $common_comm, $common_callchain) = @_;\n\n");

fprintf(ofp, "\tprint_header($event_name, $common_cpu, "
"$common_secs, $common_nsecs,\n\t $common_pid, "
- "$common_comm);\n}\n\n");
+ "$common_comm, $common_callchain);\n");
+ fprintf(ofp, "\tprint_backtrace($common_callchain);\n");
+ fprintf(ofp, "}\n\n");

fprintf(ofp, "sub print_header\n{\n"
"\tmy ($event_name, $cpu, $secs, $nsecs, $pid, $comm) = @_;\n\n"