eBPF for weak fields

Author: wks

tools/tracing/timeline/capture_ruby.bt

@@ -99,3 +99,9 @@ usdt:$MMTK:mmtk_ruby:update_wb_unprotected_objects_list {
         printf("update_wb_unprotected_objects_list,meta,%d,%lu,%lu,%lu\n", tid, nsecs, arg0, arg1);
     }
 }
+
+usdt:$MMTK:mmtk_ruby:update_weak_fields {
+    if (@enable_print) {
+        printf("update_weak_fields,meta,%d,%lu,%lu,%lu,%lu\n", tid, nsecs, arg0, arg1, arg2);
+    }
+}

tools/tracing/timeline/visualize_ruby.py

@@ -71,6 +71,8 @@ def enrich_meta_extra(log_processor, name, tid, ts, gc, wp, args):
 
             case "weak_cs_par_final":
                 num_entries = int(args[0])
+                if "set_name" not in wp["args"]:
+                    return
                 set_name = wp["args"]["set_name"]
                 gc["args"].setdefault(set_name, {})
                 gc["args"][set_name] |= {
@@ -178,3 +180,14 @@ def enrich_meta_extra(log_processor, name, tid, ts, gc, wp, args):
                         "diff": after - before,
                     },
                 }
+
+            case "update_weak_fields":
+                num_fields, live, forwarded = [int(x) for x in args[0:3]]
+                wp["args"] |= {
+                    "wb_unprotected_objects": {
+                        "num_fields": num_fields,
+                        "live": live,
+                        "forwarded": forwarded,
+                        "cleared": num_fields - live,
+                    },
+                }