Merge pull request iovisor#897 from brendangregg/master

statsnoop: refactor
linuxzjs · Jan 11, 2017 · a45d872 · a45d872
2 parents 1655fcd + f4ce31a
commit a45d872
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Showing 2 changed files with 12 additions and 34 deletions.
diff --git a/man/man8/statsnoop.8 b/man/man8/statsnoop.8
@@ -25,7 +25,8 @@ CONFIG_BPF and bcc.
 Print usage message.
 .TP
 \-t
-Include a timestamp column.
+Include a timestamp column: in seconds since the first event, with decimal
+places.
 .TP
 \-x
 Only print failed stats.

diff --git a/tools/statsnoop.py b/tools/statsnoop.py
@@ -44,16 +44,12 @@
 #include <linux/sched.h>
 
 struct val_t {
- u32 pid;
- u64 ts;
- char comm[TASK_COMM_LEN];
  const char *fname;
 };
 
 struct data_t {
  u32 pid;
- u64 ts;
- u64 delta;
+ u64 ts_ns;
  int ret;
  char comm[TASK_COMM_LEN];
  char fname[NAME_MAX];
@@ -69,12 +65,8 @@
  u32 pid = bpf_get_current_pid_tgid();
 
  FILTER
- if (bpf_get_current_comm(&val.comm, sizeof(val.comm)) == 0) {
- val.pid = bpf_get_current_pid_tgid();
- val.ts = bpf_ktime_get_ns();
- val.fname = filename;
- infotmp.update(&pid, &val);
- }
+ val.fname = filename;
+ infotmp.update(&pid, &val);
 
  return 0;
 };
@@ -83,20 +75,17 @@
 {
  u32 pid = bpf_get_current_pid_tgid();
  struct val_t *valp;
- struct data_t data = {};
-
- u64 tsp = bpf_ktime_get_ns();
 
  valp = infotmp.lookup(&pid);
  if (valp == 0) {
  // missed entry
  return 0;
  }
- bpf_probe_read(&data.comm, sizeof(data.comm), valp->comm);
+
+ struct data_t data = {.pid = pid};
  bpf_probe_read(&data.fname, sizeof(data.fname), (void *)valp->fname);
- data.pid = valp->pid;
- data.delta = tsp - valp->ts;
- data.ts = tsp / 1000;
+ bpf_get_current_comm(&data.comm, sizeof(data.comm));
+ data.ts_ns = bpf_ktime_get_ns();
  data.ret = PT_REGS_RC(ctx);
 
  events.perf_submit(ctx, &data, sizeof(data));
@@ -129,8 +118,7 @@
 class Data(ct.Structure):
  _fields_ = [
  ("pid", ct.c_ulonglong),
- ("ts", ct.c_ulonglong),
- ("delta", ct.c_ulonglong),
+ ("ts_ns", ct.c_ulonglong),
  ("ret", ct.c_int),
  ("comm", ct.c_char * TASK_COMM_LEN),
  ("fname", ct.c_char * NAME_MAX)
@@ -162,25 +150,14 @@ def print_event(cpu, data, size):
  err = - event.ret
 
  if start_ts == 0:
- prev_ts = start_ts
-
- if start_ts == 1:
- delta = float(delta) + (event.ts - prev_ts)
-
- if (args.failed and (event.ret >= 0)):
- start_ts = 1
- prev_ts = event.ts
- return
+ start_ts = event.ts_ns
 
  if args.timestamp:
- print("%-14.9f" % (delta / 1000000), end="")
+ print("%-14.9f" % (float(event.ts_ns - start_ts) / 1000000000), end="")
 
  print("%-6d %-16s %4d %3d %s" % (event.pid, event.comm,
  fd_s, err, event.fname))
 
- prev_ts = event.ts
- start_ts = 1
-
 # loop with callback to print_event
 b["events"].open_perf_buffer(print_event)
 while 1: