File 6771-Add-stacktrace-in-max-heap-size-log.patch of Package erlang

From 05c52ba036137d6fdeb2205d069ec4261cb23cbb Mon Sep 17 00:00:00 2001
From: Zeyu Zhang <zeyu@fb.com>
Date: Fri, 25 Aug 2023 14:21:17 -0700
Subject: [PATCH 1/3] Add stacktrace in max heap size log

This commit externs the current_stacktrace function and use it in erl_gc
when doing max heap event log. This is especially useful when debugging
a process that has been killed by the heap limit.
---
 erts/emulator/beam/erl_bif_info.c | 9 +++------
 erts/emulator/beam/erl_gc.c       | 7 ++++++-
 erts/emulator/beam/erl_process.h  | 4 ++++
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 7deec8f329..2265578f37 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -163,9 +163,6 @@ static char erts_system_version[] = ("Erlang/OTP " ERLANG_OTP_RELEASE
 static Eterm
 current_function(Process* p, ErtsHeapFactory *hfact, Process* rp,
                  int full_info, Uint reserve_size, int flags);
-static Eterm
-current_stacktrace(Process* p, ErtsHeapFactory *hfact, Process* rp,
-                   Uint reserve_size, int flags);
 
 Eterm
 erts_bld_bin_list(Uint **hpp, Uint *szp, ErlOffHeap* oh, Eterm tail)
@@ -1506,7 +1503,7 @@ process_info_aux(Process *c_p,
 	break;
 
     case ERTS_PI_IX_CURRENT_STACKTRACE:
-	res = current_stacktrace(c_p, hfact, rp, reserve_size, flags);
+	res = erts_current_stacktrace(c_p, hfact, rp, reserve_size, flags);
 	break;
 
     case ERTS_PI_IX_INITIAL_CALL:
@@ -2214,8 +2211,8 @@ current_function(Process *c_p, ErtsHeapFactory *hfact, Process* rp,
     return res;
 }
 
-static Eterm
-current_stacktrace(Process *p, ErtsHeapFactory *hfact, Process* rp,
+Eterm
+erts_current_stacktrace(Process *p, ErtsHeapFactory *hfact, Process* rp,
                    Uint reserve_size, int flags)
 {
     Uint sz;
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 4b41d87ad5..578143e685 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -3725,6 +3725,7 @@ reached_max_heap_size(Process *p, Uint total_heap_size,
             int alive = erts_is_alive;
             erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
             Eterm *o_hp, *hp, args = NIL;
+            ErtsHeapFactory hfact;
 
             /* Build the format message */
             erts_dsprintf(dsbufp, "     Process:            ~p ");
@@ -3737,9 +3738,13 @@ reached_max_heap_size(Process *p, Uint total_heap_size,
             erts_dsprintf(dsbufp, "     Error Logger:       ~p~n");
             erts_dsprintf(dsbufp, "     Message Queue Len:  ~p~n");
             erts_dsprintf(dsbufp, "     GC Info:            ~p~n");
+            erts_dsprintf(dsbufp, "     Stacktrace:         ~p~n");
 
             /* Build the args in reverse order */
-            o_hp = hp = erts_alloc(ERTS_ALC_T_TMP, 2*(alive ? 8 : 7) * sizeof(Eterm));
+            o_hp = hp = erts_alloc(ERTS_ALC_T_TMP, 2*(alive ? 9 : 8) * sizeof(Eterm));
+            erts_factory_proc_init(&hfact, p);
+            args = CONS(hp, erts_current_stacktrace(p, &hfact, p, 0 ,0), args); hp += 2;
+            erts_factory_close(&hfact);
             args = CONS(hp, msg, args); hp += 2;
             args = CONS(hp, make_small((p)->sig_inq.len), args); hp += 2;
             args = CONS(hp, am_true, args); hp += 2;
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index cbd6634c4a..f2bc7ad94f 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -2940,3 +2940,7 @@ float erts_sched_local_random_float(Uint additional_seed)
 void erts_halt(int code);
 extern erts_atomic32_t erts_halt_progress;
 extern int erts_halt_code;
+
+extern Eterm
+erts_current_stacktrace(Process* p, ErtsHeapFactory *hfact, Process* rp,
+                        Uint reserve_size, int flags);
-- 
2.35.3