MT#55283 use mmap for long running arenas

Rel: #2165

Change-Id: I5e529dbd5920870cbff09c7002aadc1f499abf82

daemon/call.c

@@ -5551,7 +5551,7 @@ static call_t *call_create(const str *callid) {
 
 	ilog(LOG_NOTICE, "Creating new call");
 	c = obj_alloc0(call_t, __call_free);
-	arena_init(&c->buffer, g_malloc, g_free);
+	arena_init(&c->buffer, memory_arena_malloc, memory_arena_free);
 	rwlock_init(&c->master_lock);
 	c->tags = str_ml_ht_new();
 	c->viabranches = str_ml_ht_new();

daemon/memory_arena.c

@@ -1,3 +1,13 @@
 #include "memory_arena.h"
+#include <sys/mman.h>
 
 __thread memory_arena_t *memory_arena;
+
+void *memory_arena_malloc(size_t size) {
+	return mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+}
+
+void memory_arena_free(void *p) {
+	size_t *s = p; // first element is the size
+	munmap(p, *s);
+}

include/memory_arena.h

@@ -8,6 +8,9 @@ typedef arena_t memory_arena_t;
 
 extern __thread memory_arena_t *memory_arena;
 
+void *memory_arena_malloc(size_t);
+void memory_arena_free(void *);
+
 INLINE void *__memory_arena_alloc(size_t len) {
 	void *ret;
 	ret = arena_alloc(memory_arena, len);

lib/arena.c

@@ -7,7 +7,9 @@
 // enable to perform each allocation separately, to make debugging (valgrind...) easier
 //#define ARENA_ALLOC_DEBUG
 
+
 struct arena_piece {
+	size_t size; // must be first
 	char *tail;
 	size_t left;
 	struct arena_piece *next;
@@ -38,6 +40,7 @@ static struct arena_piece *arena_piece_new(arena_t *arena, size_t size, void *(*
 	if (!ret)
 		return NULL;
 
+	ret->size = alloc_size;
 	ret->tail = ret->buf;
 	ret->left = alloc_size - overhead;
 	ret->next = NULL;