--- old/src/share/vm/logging/logStream.cpp	2017-06-30 20:00:25.708717700 +0200
+++ new/src/share/vm/logging/logStream.cpp	2017-06-30 20:00:25.000218300 +0200
@@ -24,11 +24,83 @@
 
 #include "precompiled.hpp"
 #include "logging/log.hpp"
-#include "logging/logStream.inline.hpp"
+#include "logging/logStream.hpp"
 
-// Create a log stream without an embedded ResourceMark.
-// The function is placed here to be called out-of-line in log.hpp.
-outputStream* create_log_stream(LogLevelType level, LogTagSet* tagset) {
-  return new LogStreamNoResourceMark(level, tagset);
+LogStream::LineBuffer::LineBuffer()
+ : _buf(_smallbuf), _cap(sizeof(_smallbuf)), _pos(0)
+{
+  _buf[0] = '\0';
+}
+
+LogStream::LineBuffer::~LineBuffer() {
+  assert(_pos == 0, "still outstanding bytes in the line buffer");
+  if (_buf != _smallbuf) {
+    os::free(_buf);
+  }
+}
+
+// try_ensure_cap tries to enlarge the capacity of the internal buffer
+// to the given atleast value. May fail if either OOM happens or atleast
+// is larger than a reasonable max of 1 M. Caller must not assume
+// capacity without checking.
+void LogStream::LineBuffer::try_ensure_cap(size_t atleast) {
+  assert(_cap >= sizeof(_smallbuf), "sanity");
+  if (_cap < atleast) {
+    const size_t reasonable_max = 1 * M;
+    size_t newcap = align_size_up(atleast + 64, 64);
+    assert(_cap <= reasonable_max, "sanity");
+    // Cap out at a reasonable max to prevent runaway leaks.
+    if (newcap > reasonable_max) {
+      newcap = reasonable_max;
+    }
+    
+    char* const newbuf = (char*) os::malloc(newcap, mtLogging);
+    if (newbuf == NULL) { // OOM. Leave object unchanged.
+      return;
+    }
+    if (_pos > 0) { // preserve old content
+      memcpy(newbuf, _buf, _pos + 1); // ..including trailing zero
+    }
+    if (_buf != _smallbuf) {
+      os::free(_buf);
+    }
+    _buf = newbuf;
+    _cap = newcap;
+  }
+  assert(_cap >= atleast, "sanity");
+}
+
+void LogStream::LineBuffer::append(const char* s, size_t len) {
+  assert(_buf[_pos] == '\0', "sanity");
+  assert(_pos < _cap, "sanity");
+  try_ensure_cap(_pos + len + 1);
+  // try_ensure_cap may not have enlarged the capacity to the full requested
+  // extend or may have not worked at all. In that case, just gracefully work
+  // with what we have already; just truncate if necessary.
+  if (_pos + len + 1 > _cap) {
+    len = _cap - _pos - 1;
+    if (len == 0) {
+      return;
+    }
+  }
+  memcpy(_buf + _pos, s, len);
+  _pos += len;
+  _buf[_pos] = '\0';
+}
+
+void LogStream::LineBuffer::reset() {
+  _pos = 0;
+  _buf[_pos] = '\0';
+}
+
+void LogStream::write(const char* s, size_t len) {
+  if (len > 0 && s[len - 1] == '\n') {
+    _current_line.append(s, len - 1); // omit the newline.
+    _log_handle.print("%s", _current_line.ptr());
+    _current_line.reset();
+  } else {
+    _current_line.append(s, len);
+  }
+  update_position(s, len);
 }