--- old/src/hotspot/os/linux/perfMemory_linux.cpp	2018-04-20 09:16:35.462344931 +0200
+++ new/src/hotspot/os/linux/perfMemory_linux.cpp	2018-04-20 09:16:35.232344515 +0200
@@ -562,9 +562,8 @@
   // to determine the user name for the process id.
   //
   struct dirent* dentry;
-  char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal);
   errno = 0;
-  while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) {
+  while ((dentry = os::readdir(tmpdirp, NULL)) != NULL) {
 
     // check if the directory entry is a hsperfdata file
     if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) {
@@ -598,9 +597,8 @@
     }
 
     struct dirent* udentry;
-    char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal);
     errno = 0;
-    while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) {
+    while ((udentry = os::readdir(subdirp, NULL)) != NULL) {
 
       if (filename_to_pid(udentry->d_name) == searchpid) {
         struct stat statbuf;
@@ -644,11 +642,9 @@
       }
     }
     os::closedir(subdirp);
-    FREE_C_HEAP_ARRAY(char, udbuf);
     FREE_C_HEAP_ARRAY(char, usrdir_name);
   }
   os::closedir(tmpdirp);
-  FREE_C_HEAP_ARRAY(char, tdbuf);
 
   return(oldest_user);
 }
@@ -770,10 +766,9 @@
   // opendir/readdir.
   //
   struct dirent* entry;
-  char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal);
 
   errno = 0;
-  while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) {
+  while ((entry = os::readdir(dirp, NULL)) != NULL) {
 
     pid_t pid = filename_to_pid(entry->d_name);
 
@@ -810,8 +805,6 @@
 
   // close the directory and reset the current working directory
   close_directory_secure_cwd(dirp, saved_cwd_fd);
-
-  FREE_C_HEAP_ARRAY(char, dbuf);
 }
 
 // make the user specific temporary directory. Returns true if