X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FThreadPaused.c;h=2a3f3559966006b2435c526b93352a741ce75da5;hb=e50364a5a8e5d736445cd8e5b10a813ec0a5a2e0;hp=5463deecb8dc8c9a69e62a2c24de278dc2bf1e0a;hpb=0fa59deb44b8a1a0b44ee2b4cc4ae0db31dec038;p=ghc-hetmet.git

diff --git a/rts/ThreadPaused.c b/rts/ThreadPaused.c
index 5463dee..2a3f355 100644
--- a/rts/ThreadPaused.c
+++ b/rts/ThreadPaused.c
@@ -195,6 +195,10 @@ threadPaused(Capability *cap, StgTSO *tso)
     maybePerformBlockedException (cap, tso);
     if (tso->what_next == ThreadKilled) { return; }
 
+    // NB. Blackholing is *not* optional, we must either do lazy
+    // blackholing, or eager blackholing consistently.  See Note
+    // [upd-black-hole] in sm/Scav.c.
+
     stack_end = &tso->stack[tso->stack_size];
     
     frame = (StgClosure *)tso->sp;
@@ -250,9 +254,6 @@ threadPaused(Capability *cap, StgTSO *tso)
 	    }
 
 	    if (bh->header.info != &stg_CAF_BLACKHOLE_info) {
-#if (!defined(LAZY_BLACKHOLING)) && defined(DEBUG)
-		debugBelch("Unexpected lazy BHing required at 0x%04lx\n",(long)bh);
-#endif
 		// zero out the slop so that the sanity checker can tell
 		// where the next closure is.
 		DEBUG_FILL_SLOP(bh);
@@ -261,7 +262,7 @@ threadPaused(Capability *cap, StgTSO *tso)
 		// We pretend that bh is now dead.
 		LDV_recordDead_FILL_SLOP_DYNAMIC((StgClosure *)bh);
 #endif
-
+                // an EAGER_BLACKHOLE gets turned into a BLACKHOLE here.
 #ifdef THREADED_RTS
                 cur_bh_info = (const StgInfoTable *)
                     cas((StgVolatilePtr)&bh->header.info,