This patch implemnet a fork function and a exit function in perf_top->tool to
respond to
PERF_RECORD_FORK & PERF_RECORD_EXIT events. In the fork function
(perf_top__process_event_fork), the information of the new thread is added into
thread_map. The fd and mmap of the new thread are created in this function also.
In the exit function (perf_top__process_event_exit), the information of the
exited
thread are removed from thread_map. The fd and mmap of this thread are closed
in this function also.
Based on this patch, 'perf top -p $pid' can be aware of thread's fork and exit
on-the-fly.
The new forked threads' sample events can be got by 'perf top'. And the symbols
of the new
forked threads can be display on the ui.
Cc: David Ahern <dsah...@gmail.com>
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: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang....@taobao.com>
---
tools/perf/builtin-top.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 135 insertions(+)
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index b3650e3..e7978ce 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -844,6 +844,17 @@ static void perf_top__mmap_read_idx(struct perf_top *top,
int idx)
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, machine);
+
+ if (cpu_map__all(top->evlist->cpus) &&
+ event->header.type == PERF_RECORD_EXIT) {
+ int close_nr;
+
+ close_nr = (&top->tool)->exit(&top->tool, event,
+ &sample, machine);
+ if (close_nr == idx)
+ return;
+ }
+
switch (origin) {
case PERF_RECORD_MISC_USER:
++top->us_samples;
@@ -896,6 +907,26 @@ static void perf_top__mmap_read(struct perf_top *top)
perf_top__mmap_read_idx(top, i);
}
+static void perf_top__append_thread(struct perf_top *top, int append_nr,
+ bool need_realloc)
+{
+ struct perf_evsel *counter;
+ struct perf_evlist *evlist = top->evlist;
+ int err;
+
+ list_for_each_entry(counter, &evlist->entries, node) {
+ err = perf_evsel__append_open(counter, top->evlist->cpus,
+ top->evlist->threads,
+ append_nr, need_realloc);
+
+ if (err == ESRCH) {
+ top->evlist->threads->map[append_nr] = -1;
+ clear_bit(append_nr, top->evlist->threads->bitmap);
+ return;
+ } else if (err < 0)
+ ui__error("append open error: %d\n", errno);
+ }
+}
+
static void perf_top__start_counters(struct perf_top *top)
{
struct perf_evsel *counter;
@@ -1174,12 +1205,116 @@ setup:
return 0;
}
+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)
+{
+ struct perf_top *top = container_of(tool, struct perf_top, tool);
+ pid_t tid = event->fork.tid;
+ pid_t ptid = event->fork.ptid;
+ int append_nr = -1;
+ int thread;
+
+ /*
+ * There are 2 same fork events are received while a thread was forked.
+ * This may be a kernel bug.
+ */
+ for_each_set_bit(thread, top->evlist->threads->bitmap, PID_MAX_DEFAULT)
+ if (tid == top->evlist->threads->map[thread])
+ return -1;
+
+ for_each_set_bit(thread, top->evlist->threads->bitmap, PID_MAX_DEFAULT)
{
+ /*
+ * If new thread's parent is not target task, just ignore it.
+ */
+ if (ptid == top->evlist->threads->map[thread]) {
+ bool realloc_need;
+
+ append_nr = thread_map__update(&(top->evlist->threads),
+ tid, &realloc_need);
+ /*
+ * Open counters for new thread.
+ */
+ perf_top__append_thread(top, append_nr, realloc_need);
+
+ if (perf_evlist__mmap(top->evlist, top->mmap_pages,
+ false, append_nr, realloc_need) <
0) {
+ ui__error("mmap append error!\n");
+ return -1;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int close_thread(struct perf_top *top, int close_nr)
+{
+ struct perf_evsel *evsel;
+
+ clear_bit(close_nr, top->evlist->threads->bitmap);
+
+ top->evlist->threads->map[close_nr] = -1;
+ top->evlist->threads->nr--;
+
+ if (cpu_map__all(top->evlist->cpus)) {
+ munmap(top->evlist->mmap[close_nr].base, top->evlist->mmap_len);
+ top->evlist->mmap[close_nr].base = NULL;
+ top->evlist->nr_mmaps--;
+ }
+
+ perf_evlist_remove_pollfd(top->evlist, close_nr);
+
+ list_for_each_entry(evsel, &top->evlist->entries, node) {
+ int cpu;
+
+ for (cpu = 0; cpu < cpu_map__nr(evsel->cpus); cpu++) {
+ int fd;
+
+ if (evsel->attr.read_format & PERF_FORMAT_ID)
+ perf_evlist__id_remove(evsel, cpu, close_nr);
+
+ fd = FD(evsel, cpu, close_nr);
+ if (fd)
+ close(fd);
+ }
+ }
+
+ return 0;
+}
+
+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)
+{
+ struct perf_top *top = container_of(tool, struct perf_top, tool);
+ pid_t tid = event->fork.tid;
+ int bit;
+ int close_nr = 0;
+
+ for_each_set_bit(bit, top->evlist->threads->bitmap, PID_MAX_DEFAULT) {
+ if (tid == top->evlist->threads->map[bit]) {
+ close_thread(top, bit);
+ close_nr = bit;
+ }
+ }
+
+ return close_nr;
+}
+
int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
{
struct perf_evsel *pos;
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,
.freq = 4000, /* 4 KHz */
--
1.7.9.5
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