Merge pull request erlang#7236 from jhogberg/john/erts/extend-allocat…

…ion-tags-26/OTP-18577 erts/instrument: Extend allocation tags with per-process/port and code tracking
kevsmith · May 27, 2023 · a984d16 · a984d16
2 parents 24b0d99 + 4ff9a93
commit a984d16
Show file tree

Hide file tree

Showing 15 changed files with 474 additions and 221 deletions.
diff --git a/erts/doc/src/erts_alloc.xml b/erts/doc/src/erts_alloc.xml
@@ -576,7 +576,7 @@
             <seeerl marker="runtime_tools:instrument"><c>instrument</c></seeerl>
             module to inspect this information.</p>
 
-          <p>The runtime overhead is one word per allocation when enabled. This
+          <p>The runtime overhead is two words per allocation when enabled. This
             may change at any time in the future.</p>
 
           <p>The default is <c>true</c> for <c>binary_alloc</c> and

diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
@@ -1381,7 +1381,35 @@ handle_au_arg(struct au_init *auip,
 		auip->init.util.acful = 0;
             }
 	} else if (has_prefix("atags", sub_param)) {
-            auip->init.util.atags = get_bool_value(sub_param + 5, argv, ip);
+            char *param_end = &sub_param[5];
+            char *value;
+
+            value = get_value(param_end, argv, ip);
+
+            if (sys_strcmp(value, "true") == 0) {
+                auip->init.util.atags = 1;
+            } else if (sys_strcmp(value, "false") == 0) {
+                auip->init.util.atags = 0;
+            } else if (sys_strcmp(value, "code") == 0) {
+                /* Undocumented option for point-of-origin tracking: overrides
+                 * per-pid/port tracking in favor of tracking which Erlang code
+                 * led to the allocation (best effort, but pretty accurate
+                 * under the JIT). */
+                auip->init.util.atags = 2;
+
+#if !defined(BEAMASM)
+                if (!erts_alcu_enable_code_atags) {
+                    erts_fprintf(stderr,
+                                 "WARNING: The experimental +M<S>atags code "
+                                 "flag is inaccurate under the interpreter. "
+                                 "Consider running with the JIT instead\n");
+                }
+#endif
+
+                erts_alcu_enable_code_atags = 1;
+            } else {
+                bad_value(sub_param, param_end, value);
+            }
         }
 	else
 	    goto bad_switch;

diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
@@ -289,7 +289,7 @@ type    MAP_TRAP        SHORT_LIVED     PROCESSES       map_bif_trap_state
 
 type	ENVIRONMENT	SYSTEM		SYSTEM		environment
 
-type	PERSISTENT_TERM	LONG_LIVED	CODE		persisten_term
+type	PERSISTENT_TERM	LONG_LIVED	CODE		persistent_term
 type	PERSISTENT_LOCK_Q SHORT_LIVED	SYSTEM		persistent_lock_q
 type	PERSISTENT_TERM_TMP SHORT_LIVED	SYSTEM		persistent_term_tmp_table