Revert "Per-thread allocation counters and limits"

Problems were found on 32-bit platforms, I'll commit again when I have a fix.

This reverts the following commits:
   54b31f744848da872c7c6366dea840748e01b5cf
   b0534f78a73f972e279eed4447a5687bd6a8308e

5 files changed, 14 insertions, 43 deletions

diff --git a/includes/CodeGen.Platform.hs b/includes/CodeGen.Platform.hs
index f3abb3d275..3d6dd41ae4 100644
--- a/includes/CodeGen.Platform.hs
+++ b/includes/CodeGen.Platform.hs
@@ -741,8 +741,10 @@ globalRegMaybe CurrentTSO               = Just (RealRegSingle REG_CurrentTSO)
 # ifdef REG_CurrentNursery
 globalRegMaybe CurrentNursery           = Just (RealRegSingle REG_CurrentNursery)
 # endif
-#endif
 globalRegMaybe _                        = Nothing
+#else
+globalRegMaybe = panic "globalRegMaybe not defined for this platform"
+#endif
 
 freeReg :: RegNo -> FastBool
 
diff --git a/includes/rts/Constants.h b/includes/rts/Constants.h
index a7eef0fb26..842c37b369 100644
--- a/includes/rts/Constants.h
+++ b/includes/rts/Constants.h
@@ -275,12 +275,6 @@
 #define TSO_SQUEEZED 128
 
 /*
- * Enables the AllocationLimitExceeded exception when the thread's
- * allocation limit goes negative.
- */
-#define TSO_ALLOC_LIMIT 256
-
-/*
  * The number of times we spin in a spin lock before yielding (see
  * #3758).  To tune this value, use the benchmark in #3758: run the
  * server with -N2 and the client both on a dual-core.  Also make sure
diff --git a/includes/rts/Flags.h b/includes/rts/Flags.h
index ec542701df..bf6a7f3c5c 100644
--- a/includes/rts/Flags.h
+++ b/includes/rts/Flags.h
@@ -56,14 +56,6 @@ struct GC_FLAGS {
     rtsBool doIdleGC;
 
     StgWord heapBase;           /* address to ask the OS for memory */
-
-    StgWord allocLimitGrace;    /* units: *blocks*
-                                 * After an AllocationLimitExceeded
-                                 * exception has been raised, how much
-                                 * extra space is given to the thread
-                                 * to handle the exception before we
-                                 * raise it again.
-                                 */
 };
 
 struct DEBUG_FLAGS {  
diff --git a/includes/rts/Threads.h b/includes/rts/Threads.h
index f6264adfb9..da6f7a4add 100644
--- a/includes/rts/Threads.h
+++ b/includes/rts/Threads.h
@@ -42,12 +42,8 @@ StgRegTable * resumeThread  (void *);
 //
 // Thread operations from Threads.c
 //
-int     cmp_thread                       (StgPtr tso1, StgPtr tso2);
-int     rts_getThreadId                  (StgPtr tso);
-HsInt64 rts_getThreadAllocationCounter   (StgPtr tso);
-void    rts_setThreadAllocationCounter   (StgPtr tso, HsInt64 i);
-void    rts_enableThreadAllocationLimit  (StgPtr tso);
-void    rts_disableThreadAllocationLimit (StgPtr tso);
+int    cmp_thread      (StgPtr tso1, StgPtr tso2);
+int    rts_getThreadId (StgPtr tso);
 
 #if !defined(mingw32_HOST_OS)
 pid_t  forkProcess     (HsStablePtr *entry);
diff --git a/includes/rts/storage/TSO.h b/includes/rts/storage/TSO.h
index b933067574..187b6682e0 100644
--- a/includes/rts/storage/TSO.h
+++ b/includes/rts/storage/TSO.h
@@ -145,18 +145,15 @@ typedef struct StgTSO_ {
     */
     struct StgBlockingQueue_ *bq;
 
-    /*
-     * The allocation limit for this thread, which is updated as the
-     * thread allocates.  If the value drops below zero, and
-     * TSO_ALLOC_LIMIT is set in flags, we raise an exception in the
-     * thread, and give the thread a little more space to handle the
-     * exception before we raise the exception again.
-     *
-     * This is an integer, because we might update it in a place where
-     * it isn't convenient to raise the exception, so we want it to
-     * stay negative until we get around to checking it.
-     */
-    StgInt64  alloc_limit;     /* in bytes */
+#ifdef TICKY_TICKY
+    /* TICKY-specific stuff would go here. */
+#endif
+#ifdef PROFILING
+    StgTSOProfInfo prof;
+#endif
+#ifdef mingw32_HOST_OS
+    StgWord32 saved_winerror;
+#endif
 
     /*
      * sum of the sizes of all stack chunks (in words), used to decide
@@ -171,16 +168,6 @@ typedef struct StgTSO_ {
      */
     StgWord32  tot_stack_size;
 
-#ifdef TICKY_TICKY
-    /* TICKY-specific stuff would go here. */
-#endif
-#ifdef PROFILING
-    StgTSOProfInfo prof;
-#endif
-#ifdef mingw32_HOST_OS
-    StgWord32 saved_winerror;
-#endif
-
 } *StgTSOPtr;
 
 typedef struct StgStack_ {