[tip:perf/core] perf trace: Support interrupted syscalls

From: tip-bot for Arnaldo Carvalho de Melo
Date: Thu Oct 25 2012 - 04:04:10 EST

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Commit-ID: 752fde44fd1c4a411d709c7d4ad0f121f427f234
Gitweb: http://git.kernel.org/tip/752fde44fd1c4a411d709c7d4ad0f121f427f234
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Sat, 6 Oct 2012 18:43:19 -0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 24 Oct 2012 17:23:03 -0200

perf trace: Support interrupted syscalls

Using the same strategies as in the tmp.perf/trace2, i.e. the 'trace'
tool implemented by tglx, just updated to the current codebase.

Example:

[root@sandy linux]# perf trace usleep 1 | tail
2.003: mmap(addr: 0, len: 4096, prot: 3, flags: 34, fd: 4294967295, off: 0 ) = -2128396288
2.017: mmap(addr: 0, len: 4096, prot: 3, flags: 34, fd: 4294967295, off: 0 ) = -2128400384
2.029: arch_prctl(option: 4098, arg2: 140146949441280, arg3: 140146949435392, arg4: 34, arg5: 4294967295) = 0
2.084: mprotect(start: 208741634048, len: 16384, prot: 1 ) = 0
2.098: mprotect(start: 208735956992, len: 4096, prot: 1 ) = 0
2.122: munmap(addr: 140146949447680, len: 91882 ) = 0
2.359: brk(brk: 0 ) = 28987392
2.371: brk(brk: 29122560 ) = 29122560
2.490: nanosleep(rqtp: 140735694241504, rmtp: 0 ) = 0
2.507: exit_group(error_code: 0
[root@sandy linux]#

For now the timestamp and duration are always on, will be selectable.

Also if multiple threads are being monitored, its tid will appear.

The ret output continues to be interpreted a la strace.

Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-ly9ulroru4my5isn0xe9gr0m@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 199 +++++++++++++++++++++++++++++++++++++++-----
tools/perf/util/util.h | 4 +
2 files changed, 181 insertions(+), 22 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 14b3229..873f50b 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1,5 +1,8 @@
#include "builtin.h"
+#include "util/color.h"
#include "util/evlist.h"
+#include "util/machine.h"
+#include "util/thread.h"
#include "util/parse-options.h"
#include "util/thread_map.h"
#include "event-parse.h"
@@ -43,6 +46,36 @@ struct syscall {
struct syscall_fmt *fmt;
};

+struct thread_trace {
+ u64 entry_time;
+ u64 exit_time;
+ bool entry_pending;
+ char *entry_str;
+};
+
+static struct thread_trace *thread_trace__new(void)
+{
+ return zalloc(sizeof(struct thread_trace));
+}
+
+static struct thread_trace *thread__trace(struct thread *thread)
+{
+ if (thread == NULL)
+ goto fail;
+
+ if (thread->priv == NULL)
+ thread->priv = thread_trace__new();
+
+ if (thread->priv == NULL)
+ goto fail;
+
+ return thread->priv;
+fail:
+ color_fprintf(stdout, PERF_COLOR_RED,
+ "WARNING: not enough memory, dropping samples!\n");
+ return NULL;
+}
+
struct trace {
int audit_machine;
struct {
@@ -50,8 +83,18 @@ struct trace {
struct syscall *table;
} syscalls;
struct perf_record_opts opts;
+ struct machine host;
+ u64 base_time;
+ bool multiple_threads;
};

+static size_t trace__fprintf_tstamp(struct trace *trace, u64 tstamp, FILE *fp)
+{
+ double ts = (double)(tstamp - trace->base_time) / NSEC_PER_MSEC;
+
+ return fprintf(fp, "%10.3f: ", ts);
+}
+
static bool done = false;

static void sig_handler(int sig __maybe_unused)
@@ -59,6 +102,67 @@ static void sig_handler(int sig __maybe_unused)
done = true;
}

+static size_t trace__fprintf_entry_head(struct trace *trace, struct thread *thread,
+ u64 tstamp, FILE *fp)
+{
+ size_t printed = trace__fprintf_tstamp(trace, tstamp, fp);
+
+ if (trace->multiple_threads)
+ printed += fprintf(fp, "%d ", thread->pid);
+
+ return printed;
+}
+
+static int trace__process_event(struct machine *machine, union perf_event *event)
+{
+ int ret = 0;
+
+ switch (event->header.type) {
+ case PERF_RECORD_LOST:
+ color_fprintf(stdout, PERF_COLOR_RED,
+ "LOST %" PRIu64 " events!\n", event->lost.lost);
+ ret = machine__process_lost_event(machine, event);
+ default:
+ ret = machine__process_event(machine, event);
+ break;
+ }
+
+ return ret;
+}
+
+static int trace__tool_process(struct perf_tool *tool __maybe_unused,
+ union perf_event *event,
+ struct perf_sample *sample __maybe_unused,
+ struct machine *machine)
+{
+ return trace__process_event(machine, event);
+}
+
+static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist)
+{
+ int err = symbol__init();
+
+ if (err)
+ return err;
+
+ machine__init(&trace->host, "", HOST_KERNEL_ID);
+ machine__create_kernel_maps(&trace->host);
+
+ if (perf_target__has_task(&trace->opts.target)) {
+ err = perf_event__synthesize_thread_map(NULL, evlist->threads,
+ trace__tool_process,
+ &trace->host);
+ } else {
+ err = perf_event__synthesize_threads(NULL, trace__tool_process,
+ &trace->host);
+ }
+
+ if (err)
+ symbol__exit();
+
+ return err;
+}
+
static int trace__read_syscall_info(struct trace *trace, int id)
{
char tp_name[128];
@@ -100,7 +204,8 @@ static int trace__read_syscall_info(struct trace *trace, int id)
return sc->tp_format != NULL ? 0 : -1;
}

-static size_t syscall__fprintf_args(struct syscall *sc, unsigned long *args, FILE *fp)
+static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
+ unsigned long *args)
{
int i = 0;
size_t printed = 0;
@@ -109,12 +214,15 @@ static size_t syscall__fprintf_args(struct syscall *sc, unsigned long *args, FIL
struct format_field *field;

for (field = sc->tp_format->format.fields->next; field; field = field->next) {
- printed += fprintf(fp, "%s%s: %ld", printed ? ", " : "",
- field->name, args[i++]);
+ printed += scnprintf(bf + printed, size - printed,
+ "%s%s: %ld", printed ? ", " : "",
+ field->name, args[i++]);
}
} else {
while (i < 6) {
- printed += fprintf(fp, "%sarg%d: %ld", printed ? ", " : "", i, args[i]);
+ printed += scnprintf(bf + printed, size - printed,
+ "%sarg%d: %ld",
+ printed ? ", " : "", i, args[i]);
++i;
}
}
@@ -153,10 +261,14 @@ out_cant_read:
static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
struct perf_sample *sample)
{
+ char *msg;
void *args;
+ size_t printed = 0;
+ struct thread *thread = machine__findnew_thread(&trace->host, sample->tid);
struct syscall *sc = trace__syscall_info(trace, evsel, sample);
+ struct thread_trace *ttrace = thread__trace(thread);

- if (sc == NULL)
+ if (ttrace == NULL || sc == NULL)
return -1;

args = perf_evsel__rawptr(evsel, sample, "args");
@@ -165,8 +277,25 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
return -1;
}

- printf("%s(", sc->name);
- syscall__fprintf_args(sc, args, stdout);
+ ttrace = thread->priv;
+
+ if (ttrace->entry_str == NULL) {
+ ttrace->entry_str = malloc(1024);
+ if (!ttrace->entry_str)
+ return -1;
+ }
+
+ ttrace->entry_time = sample->time;
+ msg = ttrace->entry_str;
+ printed += scnprintf(msg + printed, 1024 - printed, "%s(", sc->name);
+
+ printed += syscall__scnprintf_args(sc, msg + printed, 1024 - printed, args);
+
+ if (!strcmp(sc->name, "exit_group") || !strcmp(sc->name, "exit")) {
+ trace__fprintf_entry_head(trace, thread, sample->time, stdout);
+ printf("%-70s\n", ttrace->entry_str);
+ } else
+ ttrace->entry_pending = true;

return 0;
}
@@ -175,13 +304,29 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
struct perf_sample *sample)
{
int ret;
+ struct thread *thread = machine__findnew_thread(&trace->host, sample->tid);
+ struct thread_trace *ttrace = thread__trace(thread);
struct syscall *sc = trace__syscall_info(trace, evsel, sample);

- if (sc == NULL)
+ if (ttrace == NULL || sc == NULL)
return -1;

ret = perf_evsel__intval(evsel, sample, "ret");

+ ttrace = thread->priv;
+
+ ttrace->exit_time = sample->time;
+
+ trace__fprintf_entry_head(trace, thread, sample->time, stdout);
+
+ if (ttrace->entry_pending) {
+ printf("%-70s", ttrace->entry_str);
+ } else {
+ printf(" ... [");
+ color_fprintf(stdout, PERF_COLOR_YELLOW, "continued");
+ printf("]: %s()", sc->name);
+ }
+
if (ret < 0 && sc->fmt && sc->fmt->errmsg) {
char bf[256];
const char *emsg = strerror_r(-ret, bf, sizeof(bf)),
@@ -194,6 +339,9 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
printf(") = %d", ret);

putchar('\n');
+
+ ttrace->entry_pending = false;
+
return 0;
}

@@ -221,6 +369,12 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
goto out_delete_evlist;
}

+ err = trace__symbols_init(trace, evlist);
+ if (err < 0) {
+ printf("Problems initializing symbol libraries!\n");
+ goto out_delete_evlist;
+ }
+
perf_evlist__config_attrs(evlist, &trace->opts);

signal(SIGCHLD, sig_handler);
@@ -251,6 +405,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
if (forks)
perf_evlist__start_workload(evlist);

+ trace->multiple_threads = evlist->threads->map[0] == -1 || evlist->threads->nr > 1;
again:
before = nr_events;

@@ -264,32 +419,32 @@ again:

++nr_events;

- switch (type) {
- case PERF_RECORD_SAMPLE:
- break;
- case PERF_RECORD_LOST:
- printf("LOST %" PRIu64 " events!\n", event->lost.lost);
- continue;
- default:
- printf("Unexpected %s event, skipping...\n",
- perf_event__name(type));
- continue;
- }
-
err = perf_evlist__parse_sample(evlist, event, &sample);
if (err) {
printf("Can't parse sample, err = %d, skipping...\n", err);
continue;
}

+ if (trace->base_time == 0)
+ trace->base_time = sample.time;
+
+ if (type != PERF_RECORD_SAMPLE) {
+ trace__process_event(&trace->host, event);
+ continue;
+ }
+
evsel = perf_evlist__id2evsel(evlist, sample.id);
if (evsel == NULL) {
printf("Unknown tp ID %" PRIu64 ", skipping...\n", sample.id);
continue;
}

- if (evlist->threads->map[0] == -1 || evlist->threads->nr > 1)
- printf("%d ", sample.tid);
+ if (sample.raw_data == NULL) {
+ printf("%s sample with no payload for tid: %d, cpu %d, raw_size=%d, skipping...\n",
+ perf_evsel__name(evsel), sample.tid,
+ sample.cpu, sample.raw_size);
+ continue;
+ }

if (sample.raw_data == NULL) {
printf("%s sample with no payload for tid: %d, cpu %d, raw_size=%d, skipping...\n",
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index a6b83f8..0d85209 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -198,6 +198,10 @@ static inline int has_extension(const char *filename, const char *ext)
#undef tolower
#undef toupper

+#ifndef NSEC_PER_MSEC
+#define NSEC_PER_MSEC 1000000L
+#endif
+
extern unsigned char sane_ctype[256];
#define GIT_SPACE 0x01
#define GIT_DIGIT 0x02
--
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Next message: tip-bot for Arnaldo Carvalho de Melo: "[tip:perf/core] perf trace: Add an event duration column"
Previous message: Shawn Guo: "Re: [PATCH] RFC: leds-pwm: don't disable pwm when setting brightnessto 0"
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