--- mysql-8.0.17/storage/innobase/handler/ha_innodb.cc.orig	2019-09-22 17:18:33.000000000 -0700
+++ mysql-8.0.17/storage/innobase/handler/ha_innodb.cc	2019-09-22 17:18:49.000000000 -0700
@@ -57,6 +57,10 @@
 #include <strfunc.h>
 #include <time.h>
 
+#if defined __APPLE__ && (MAC_OS_X_VERSION_MIN_REQUIRED < 101100)
+#include <sys/sysctl.h>
+#endif
+
 #include <sql_table.h>
 #include "mysql/components/services/system_variable_source.h"
 
@@ -294,10 +298,19 @@
 #undef get_sys_mem
 #define get_sys_mem get_mem_GlobalMemoryStatus
 #else
+#if defined __APPLE__ && (MAC_OS_X_VERSION_MIN_REQUIRED < 101100)
+static double get_mem_sysconf() {
+     uint64_t mem_size;
+     size_t len = sizeof(mem_size);
+     sysctlbyname("hw.memsize", &mem_size, &len, NULL, 0);
+     return (((double)mem_size) / GB);
+}
+#else
 static double get_mem_sysconf() {
   return (((double)sysconf(_SC_PHYS_PAGES)) *
           ((double)sysconf(_SC_PAGESIZE) / GB));
 }
+#endif
 #undef get_sys_mem
 #define get_sys_mem get_mem_sysconf
 #endif /* defined(_WIN32) || defined(_WIN64) */