diff --git a/glibc-revert-arena-threshold-fix.patch b/glibc-revert-arena-threshold-fix.patch
new file mode 100644
index 0000000..e0aaded
--- /dev/null
+++ b/glibc-revert-arena-threshold-fix.patch
@@ -0,0 +1,44 @@
+Revert the following fix temporarily:
+
+commit c26efef9798914e208329c0e8c3c73bb1135d9e3
+Author: Mel Gorman <mgorman@suse.de>
+Date:   Thu Apr 2 12:14:14 2015 +0530
+
+    malloc: Consistently apply trim_threshold to all heaps [BZ #17195]
+    
+
+because it makes an openjdk bug (#1209451) more prominent, crashing java
+commands.
+
+diff --git a/malloc/arena.c b/malloc/arena.c
+index 8af51f0..d85f371 100644
+--- a/malloc/arena.c
++++ b/malloc/arena.c
+@@ -658,7 +658,7 @@ heap_trim (heap_info *heap, size_t pad)
+   unsigned long pagesz = GLRO (dl_pagesize);
+   mchunkptr top_chunk = top (ar_ptr), p, bck, fwd;
+   heap_info *prev_heap;
+-  long new_size, top_size, extra, prev_size, misalign;
++  long new_size, top_size, top_area, extra, prev_size, misalign;
+ 
+   /* Can this heap go away completely? */
+   while (top_chunk == chunk_at_offset (heap, sizeof (*heap)))
+@@ -694,9 +694,16 @@ heap_trim (heap_info *heap, size_t pad)
+       set_head (top_chunk, new_size | PREV_INUSE);
+       /*check_chunk(ar_ptr, top_chunk);*/
+     }
++
++  /* Uses similar logic for per-thread arenas as the main arena with systrim
++     by preserving the top pad and at least a page.  */
+   top_size = chunksize (top_chunk);
+-  extra = (top_size - pad - MINSIZE - 1) & ~(pagesz - 1);
+-  if (extra < (long) pagesz)
++  top_area = top_size - MINSIZE - 1;
++  if (top_area <= pad)
++    return 0;
++
++  extra = ALIGN_DOWN(top_area - pad, pagesz);
++  if ((unsigned long) extra < mp_.trim_threshold)
+     return 0;
+ 
+   /* Try to shrink. */
diff --git a/glibc.spec b/glibc.spec
index 97eba8a..dd0b4e6 100644
--- a/glibc.spec
+++ b/glibc.spec
@@ -1,6 +1,6 @@
-%define glibcsrcdir  glibc-2.21-217-g7e9c7b9
+%define glibcsrcdir  glibc-2.21-320-ga6d78c3
 %define glibcversion 2.21.90
-%define glibcrelease 10%{?dist}
+%define glibcrelease 11%{?dist}
 # Pre-release tarballs are pulled in from git using a command that is
 # effectively:
 #
@@ -209,6 +209,9 @@ Patch0053: %{name}-cs-path.patch
 # Remove the clock_* functions and use the ones in libc like librt does.
 Patch0054: %{name}-rtkaio-clock.patch
 
+# Temporarily revert a fix to work around bz #1209451.
+Patch0055: %{name}-revert-arena-threshold-fix.patch
+
 ##############################################################################
 #
 # Patches from upstream
@@ -579,6 +582,7 @@ package or when debugging this package.
 %patch0052 -p1
 %patch0053 -p1
 %patch0054 -p1
+%patch0055 -p1 -R
 
 ##############################################################################
 # %%prep - Additional prep required...
@@ -1751,6 +1755,10 @@ rm -f *.filelist*
 %endif
 
 %changelog
+* Thu May 07 2015 Siddhesh Poyarekar <siddhesh@redhat.com> - 2.21.90-11
+- Auto-sync with upstream master.
+- Revert arena threshold fix to work around #1209451.
+
 * Tue Apr 07 2015 Siddhesh Poyarekar <siddhesh@redhat.com> - 2.21.90-10
 - Revert last auto-sync (#1209451).
 
diff --git a/sources b/sources
index 5e02458..bfaee1f 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-307bb73bbc157901cd143f14c712291a  glibc-2.21-217-g7e9c7b9.tar.gz
+a98e79a6a741f842fd1505e54b5face8  glibc-2.21-320-ga6d78c3.tar.gz