Expanded ftrace2pyplot for user-supplied ftrace function name

src/aarch64-linux-flush-dcache/visualizer/ftrace2pyplot/arguments.py

@@ -6,6 +6,10 @@ parser = argparse.ArgumentParser(
 )
 
 # Positional
+parser.add_argument(
+    "fn", metavar="function", type=str,
+    help="ftrace function name to filter entries for"
+)
 parser.add_argument(
     "directory", type=str, help="ftrace-cmd output .dat directory"
 )

src/aarch64-linux-flush-dcache/visualizer/ftrace2pyplot/core.py

@@ -1,7 +1,7 @@
 from os import path
 from argparse import Namespace
 import glob
-from typing import List, Tuple, Union
+from typing import List, Tuple, Union, Optional
 import re
 
 import trappy
@@ -12,7 +12,7 @@ import matplotlib.pyplot as plt
 
 from .arguments import parser
 
-def parse_basename_into_byte_count(basename: str) -> int:
+def parse_basename_to_kibs(basename: str) -> int:
     ret: int = -1
 
     regex = re.compile(r"(?P<size>[0-9]+)(?P<unit>[kmgKMG])")
@@ -31,7 +31,7 @@ def parse_basename_into_byte_count(basename: str) -> int:
 def clip_to(
         dataset: Union[pd.Series, pd.DataFrame],
         percentile: float,
-        axis: int = None
+        axis: Optional[int] = None
 ) -> Union[pd.Series, pd.DataFrame]:
     assert(0 <= percentile <= 1)
     if percentile == .0:
@@ -47,17 +47,22 @@ def clip_to(
 
     return clipped
 
-def parse_function_graph_ftrace(trace_fpath: str):
-    trace = trappy.FTrace(trace_fpath)
+def parse_function_graph_ftrace(
+        ftrace_dat_path: str,
+        fn: str
+) -> Optional[pd.DataFrame]:
+    trace = trappy.FTrace(ftrace_dat_path)
     fngraph_df: pd.DataFrame = trace.funcgraph_exit.data_frame
     assert fngraph_df is not None
 
-    # Sieve `__dcache_clean_poc` entries
+    # Sieve function entries
     # Notably, the long ones are mostly preempted by e.g., softirq (rcu, etc.)
     # I should prob. identify them but whatever
     # Other long ones that are NOT preempted may be due to QEMU process
     # scheduling on host, not sure
-    fngraph_df = fngraph_df.loc[fngraph_df["func"] == "__dcache_clean_poc"]
+    fngraph_df = fngraph_df.loc[fngraph_df["func"] == fn]
+    if fngraph_df.shape[0] == 0:
+        return None
 
     # Compute runtime of function
     fngraph_df.loc[:, "rettime"] = (fngraph_df["rettime"]
@@ -83,8 +88,11 @@ def run(args: Namespace):
 
     for ftrace_dat_path in ftrace_dat_paths:
         print("Loading \"{}\"...".format(ftrace_dat_path))
-        fngraph_df = parse_function_graph_ftrace(ftrace_dat_path)
-        size_in_kb = parse_basename_into_byte_count(
+        fngraph_df = parse_function_graph_ftrace(ftrace_dat_path, args.fn)
+        if fngraph_df is None:
+            print("No entry -- pass")
+            continue
+        size_in_kb = parse_basename_to_kibs(
             str(path.basename(ftrace_dat_path).split(".")[:-1]))
         ftrace_dfs.append((size_in_kb, fngraph_df))