new utility to name a region

include/mimalloc-internal.h

@@ -78,6 +78,7 @@ void*      _mi_os_alloc(size_t size, mi_stats_t* stats);           // to allocat
 void       _mi_os_free(void* p, size_t size, mi_stats_t* stats);   // to free thread local data
 size_t     _mi_os_good_alloc_size(size_t size);
 bool       _mi_os_has_overcommit(void);
+bool       _mi_os_alloc_named(void* p, size_t size, const char *name);
 
 // memory.c
 void*      _mi_mem_alloc_aligned(size_t size, size_t alignment, bool* commit, bool* large, bool* is_pinned, bool* is_zero, size_t* id, mi_os_tld_t* tld);

include/mimalloc.h

@@ -380,6 +380,8 @@ mi_decl_nodiscard mi_decl_export mi_decl_restrict void* mi_new_n(size_t count, s
 mi_decl_nodiscard mi_decl_export void* mi_new_realloc(void* p, size_t newsize)                mi_attr_alloc_size(2);
 mi_decl_nodiscard mi_decl_export void* mi_new_reallocn(void* p, size_t newcount, size_t size) mi_attr_alloc_size2(2, 3);
 
+mi_decl_export bool mi_alloc_named(void* p, size_t size, const char *name);
+
 #ifdef __cplusplus
 }
 #endif

src/os.c

@@ -45,6 +45,7 @@ terms of the MIT license. A copy of the license can be found in the file
 #else
 #include <sys/mman.h>
 #endif
+#include <sys/prctl.h>
 #endif
 #if defined(__APPLE__)
 #include <TargetConditionals.h>
@@ -1437,3 +1438,20 @@ int _mi_os_numa_node_get(mi_os_tld_t* tld) {
   if (numa_node >= numa_count) { numa_node = numa_node % numa_count; }
   return (int)numa_node;
 }
+
+bool _mi_os_alloc_named(void* p, size_t size, const char *name) {
+  mi_assert_internal(p != NULL);
+  mi_assert_internal(name != NULL);
+#if defined(__linux__)
+#if !defined(PR_SET_VMA)
+#define PR_SET_VMA 0x53564d41
+#define PR_SET_VMA_ANON_NAME 0
+#endif
+  return (prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, (unsigned long)p, size, (unsigned long)name) == 0);
+#else
+  MI_UNUSED(p);
+  MI_UNUSED(size);
+  MI_UNUSED(name);
+  return false;
+#endif
+}

src/page.c

@@ -852,3 +852,7 @@ void* _mi_malloc_generic(mi_heap_t* heap, size_t size) mi_attr_noexcept
   // and try again, this time succeeding! (i.e. this should never recurse)
   return _mi_page_malloc(heap, page, size);
 }
+
+bool mi_alloc_named(void* p, size_t size, const char *name) {
+   return _mi_os_alloc_named(p, size, name);
+}

src/region.c

@@ -164,7 +164,6 @@ static bool mi_memid_is_arena(size_t id, mem_region_t** region, mi_bitmap_index_
   }
 }
 
-
 /* ----------------------------------------------------------------------------
   Allocate a region is allocated from the OS (or an arena)
 -----------------------------------------------------------------------------*/