Update gc tracking instructions and gdb commands.

tools/gc_activity.md

@@ -13,7 +13,7 @@ correct port. GDB is usually :3333 and JLink is :2331.
 Now, run gdb from your port directory:
 
 ```
-arm-none-eabi-gdb -x ../tools/output_gc_until_repl.txt build-metro_m0_express/firmware.elf
+arm-none-eabi-gdb -x ../../tools/output_gc_until_repl.txt build-metro_m0_express/firmware.elf
 ```
 
 This will take a little time while it breaks, backtraces and continues for every

tools/gc_activity_between_collects.py

@@ -0,0 +1,141 @@
+import sys
+import json
+
+# Map start block to current allocation info.
+current_heap = {}
+allocation_history = []
+root = {}
+
+def change_root(trace, size):
+    level = root
+    for frame in reversed(trace):
+        file_location = frame[1]
+        if file_location not in level:
+            level[file_location] = {"blocks": 0,
+                                    "file": file_location,
+                                    "function": frame[2],
+                                    "subcalls": {}}
+        level[file_location]["blocks"] += size
+        level = level[file_location]["subcalls"]
+
+total_actions = 0
+non_single_block_streak = 0
+max_nsbs = 0
+last_action = None
+last_total_actions = 0
+count = 0
+actions = {}
+last_ticks_ms = 0
+ticks_ms = 0
+block_sizes = {}
+allocation_sources = {}
+with open(sys.argv[1], "r") as f:
+    for line in f:
+        if not line.strip():
+            break
+    for line in f:
+        action = None
+        if line.startswith("Breakpoint 2"):
+            break
+        next(f) # throw away breakpoint code line
+        # print(next(f)) # first frame
+        block = 0
+        size = 0
+        trace = []
+        for line in f:
+            # print(line.strip())
+            if line[0] == "#":
+                frame = line.strip().split()
+                if frame[1].startswith("0x"):
+                    trace.append((frame[1], frame[-1], frame[3]))
+                else:
+                    trace.append(("0x0", frame[-1], frame[1]))
+            elif line[0] == "$":
+                #print(line.strip().split()[-1])
+                block = int(line.strip().split()[-1][2:], 16)
+                next_line = next(f)
+                size = int(next_line.strip().split()[-1][2:], 16)
+                # next_line = next(f)
+                # ticks_ms = int(next_line.strip().split()[-1][2:], 16)
+            if not line.strip():
+                break
+
+        action = "unknown"
+        if block not in current_heap:
+            current_heap[block] = {"start_block": block, "size": size, "start_trace": trace, "start_time": total_actions}
+            action = "alloc"
+            if size == 1:
+                max_nsbs = max(max_nsbs, non_single_block_streak)
+                non_single_block_streak = 0
+            else:
+                non_single_block_streak += 1
+            #change_root(trace, size)
+            if size not in block_sizes:
+                block_sizes[size] = 0
+            source = trace[-1][-1]
+            if source not in allocation_sources:
+                print(trace)
+                allocation_sources[source] = 0
+            allocation_sources[source] += 1
+            block_sizes[size] += 1
+        else:
+            alloc = current_heap[block]
+            alloc["end_trace"] = trace
+            alloc["end_time"] = total_actions
+            change_root(alloc["start_trace"], -1 * alloc["size"])
+            if size > 0:
+                action = "realloc"
+                current_heap[block] = {"start_block": block, "size": size, "start_trace": trace, "start_time": total_actions}
+                #change_root(trace, size)
+            else:
+                action = "free"
+                if trace[0][2] == "gc_sweep":
+                    action = "sweep"
+                    non_single_block_streak = 0
+                if (trace[3][2] == "py_gc_collect" or (trace[3][2] == "gc_deinit" and count > 1)) and last_action != "sweep":
+                    print(ticks_ms - last_ticks_ms, total_actions - last_total_actions, "gc.collect", max_nsbs)
+                    print(actions)
+                    print(block_sizes)
+                    print(allocation_sources)
+                    actions = {}
+                    block_sizes = {}
+                    allocation_sources = {}
+                    if count % 2 == 0:
+                        print()
+                    count += 1
+                    last_total_actions = total_actions
+                    last_ticks_ms = ticks_ms
+                    max_nsbs = 0
+                del current_heap[block]
+            alloc["end_cause"] = action
+            allocation_history.append(alloc)
+        if action not in actions:
+            actions[action] = 0
+        actions[action] += 1
+        last_action = action
+        #print(total_actions, non_single_block_streak, action, block, size)
+        total_actions += 1
+print(actions)
+print(max_nsbs)
+print()
+
+for alloc in current_heap.values():
+    alloc["end_trace"] = ""
+    alloc["end_time"] = total_actions
+    allocation_history.append(alloc)
+
+def print_frame(frame, indent=0):
+    for key in sorted(frame):
+        if not frame[key]["blocks"] or key.startswith("../py/malloc.c") or key.startswith("../py/gc.c"):
+            continue
+        print(" " * (indent - 1), key, frame[key]["function"], frame[key]["blocks"], "blocks")
+        print_frame(frame[key]["subcalls"], indent + 2)
+
+# print_frame(root)
+# total_blocks = 0
+# for key in sorted(root):
+#     total_blocks += root[key]["blocks"]
+# print(total_blocks, "total blocks")
+
+# with open("allocation_history.json", "w") as f:
+#     json.dump(allocation_history, f)

tools/output_gc_until_repl.txt

@@ -10,16 +10,23 @@ set logging on
 set remote hardware-breakpoint-limit 4
 
 # gc log
-break gc.c:103
+break gc.c:106
 commands
-backtrace
 p/x start_block
 p/x length
-append binary memory ram.bin &_srelocate &_estack
+p/x ticks_ms
+# backtrace output redirect is currently broken in gdb so we use up instead.
+# https://sourceware.org/bugzilla/show_bug.cgi?id=23439
+# backtrace
+up
+up
+up
+up
+# append binary memory ram.bin &_srelocate &_estack
 continue
 end
 
-break main.c:179
+break main.c:251
 
 continue