X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FThreads.c;h=936b90e884d184f7e8fe31d6365f54b98d64de68;hb=4e3542263207ae49963811aeb84927027e7bb61d;hp=2c7b2beb8678e8736da7cbbe4d3eb562baff3640;hpb=192c7d555448b8a78d57a5c01c0c20f642f2d0f3;p=ghc-hetmet.git

diff --git a/rts/Threads.c b/rts/Threads.c
index 2c7b2be..936b90e 100644
--- a/rts/Threads.c
+++ b/rts/Threads.c
@@ -505,8 +505,10 @@ unblockOne_ (Capability *cap, StgTSO *tso,
       }
       tso->cap = cap;
       appendToRunQueue(cap,tso);
-      // we're holding a newly woken thread, make sure we context switch
-      // quickly so we can migrate it if necessary.
+
+      // context-switch soonish so we can migrate the new thread if
+      // necessary.  NB. not contextSwitchCapability(cap), which would
+      // force a context switch immediately.
       cap->context_switch = 1;
   } else {
       // we'll try to wake it up on the Capability it was last on.
@@ -514,6 +516,10 @@ unblockOne_ (Capability *cap, StgTSO *tso,
   }
 #else
   appendToRunQueue(cap,tso);
+
+  // context-switch soonish so we can migrate the new thread if
+  // necessary.  NB. not contextSwitchCapability(cap), which would
+  // force a context switch immediately.
   cap->context_switch = 1;
 #endif