From: chenggang <chenggang....@taobao.com>
Many applications will fork threads on-the-fly, these threads could exit before
the main thread exit. The perf top tool should perceive the new forked threads
while we profile a special application.
If the target process fork a thread or a thread exit, we will get a
PERF_RECORD_FORK
or PERF_RECORD_EXIT events. The following callback functions can process these
events.
1) perf_top__process_event_fork()
Open a new fd for the new forked, and expend the related data structures.
2) perf_top__process_event_exit()
Close the fd of exit threadsd, and destroy the nodes in the related data
structures.
Cc: David Ahern <dsah...@gmail.com>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Cc: Arjan van de Ven <ar...@linux.intel.com>
Cc: Namhyung Kim <namhy...@gmail.com>
Cc: Yanmin Zhang <yanmin.zh...@intel.com>
Cc: Wu Fengguang <fengguang...@intel.com>
Cc: Mike Galbraith <efa...@gmx.de>
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang....@taobao.com>
---
tools/perf/builtin-top.c | 109 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 107 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index cff58e5..a591b96 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -800,7 +800,8 @@ static void perf_event__process_sample(struct perf_tool
*tool,
return;
}
-static void perf_top__mmap_read_idx(struct perf_top *top, struct perf_mmap *md)
+static int perf_top__mmap_read_idx(struct perf_top *top, struct perf_mmap *md,
+ int idx)
{
struct perf_sample sample;
struct perf_evsel *evsel;
@@ -825,6 +826,20 @@ static void perf_top__mmap_read_idx(struct perf_top *top,
struct perf_mmap *md)
if (event->header.type == PERF_RECORD_SAMPLE)
++top->samples;
+ if (cpu_map__all(top->evlist->cpus) &&
+ event->header.type == PERF_RECORD_FORK)
+ (&top->tool)->fork(&top->tool, event, &sample, NULL);
+
+ if (cpu_map__all(top->evlist->cpus) &&
+ event->header.type == PERF_RECORD_EXIT) {
+ int tidx;
+
+ tidx = (&top->tool)->exit(&top->tool, event,
+ &sample, NULL);
+ if (tidx == idx)
+ return -1;
+ }
+
switch (origin) {
case PERF_RECORD_MISC_USER:
++top->us_samples;
@@ -863,14 +878,18 @@ static void perf_top__mmap_read_idx(struct perf_top *top,
struct perf_mmap *md)
} else
++session->stats.nr_unknown_events;
}
+ return 0;
}
static void perf_top__mmap_read(struct perf_top *top)
{
struct perf_mmap *md;
+ int i = 0;
for_each_mmap(md, top->evlist) {
- perf_top__mmap_read_idx(top, md);
+ if (perf_top__mmap_read_idx(top, md, i) == -1)
+ break;
+ i++;
}
}
@@ -1025,11 +1044,97 @@ parse_callchain_opt(const struct option *opt, const
char *arg, int unset)
return record_parse_callchain_opt(opt, arg, unset);
}
+static int perf_top__append_thread(struct perf_top *top, pid_t pid)
+{
+ char msg[512];
+ struct perf_evsel *counter, *counter_err;
+ struct perf_evlist *evlist = top->evlist;
+ struct cpu_map *cpus = evlist->cpus;
+
+ counter_err = list_entry(evlist->entries.prev, struct perf_evsel, node);
+
+ list_for_each_entry(counter, &evlist->entries, node) {
+ if (perf_evsel__open_single_thread(counter, cpus, pid) < 0) {
+ if (verbose) {
+ perf_evsel__open_strerror(counter,
+
&top->record_opts.target,
+ errno, msg,
sizeof(msg));
+ ui__warning("%s\n", msg);
+ }
+ counter_err = counter;
+ goto close_opened_fd;
+ }
+ }
+
+ if (perf_evlist__mmap_thread(evlist, false) < 0)
+ goto close_opened_fd;
+
+ return 0;
+
+close_opened_fd:
+ list_for_each_entry(counter, &evlist->entries, node) {
+ perf_evsel__close_single_thread(counter, cpus->nr, -1);
+ if (counter == counter_err)
+ break;
+ }
+ return -1;
+}
+
+static int perf_top__process_event_fork(struct perf_tool *tool __maybe_unused,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample
__maybe_unused,
+ struct machine *machine __maybe_unused)
+{
+ pid_t tid = event->fork.tid;
+ struct perf_top *top = container_of(tool, struct perf_top, tool);
+ struct thread_map *threads = top->evlist->threads;
+ int ret;
+
+ ret = thread_map__append(threads, tid);
+ if (ret != 0)
+ return ret;
+
+ if (perf_top__append_thread(top, tid) < 0)
+ goto free_new_thread;
+
+ return 0;
+
+free_new_thread:
+ thread_map__remove(threads, -1);
+ return -1;
+}
+
+static int perf_top__process_event_exit(struct perf_tool *tool __maybe_unused,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample
__maybe_unused,
+ struct machine *machine __maybe_unused)
+{
+ pid_t tid = event->fork.tid;
+ struct perf_top *top = container_of(tool, struct perf_top, tool);
+ struct perf_evsel *evsel;
+ struct thread_map *threads = top->evlist->threads;
+ int tidx = thread_map__get_idx_by_pid(threads, tid);
+
+ if (tidx < 0)
+ return -1;
+
+ perf_evlist__munmap_thread(top->evlist, tidx);
+ list_for_each_entry(evsel, &top->evlist->entries, node) {
+ perf_evsel__close_single_thread(evsel, top->evlist->cpus->nr,
tidx);
+ }
+ thread_map__remove(threads, tidx);
+ return tidx;
+}
+
int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
{
int status;
char errbuf[BUFSIZ];
struct perf_top top = {
+ .tool = {
+ .fork = perf_top__process_event_fork,
+ .exit = perf_top__process_event_exit,
+ },
.count_filter = 5,
.delay_secs = 2,
.record_opts = {
--
1.7.9.5
--
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