changeset 58932:326a2b004834

8243301: Shenandoah: ditch ShenandoahAllowMixedAllocs Reviewed-by: rkennke
author shade
date Wed, 22 Apr 2020 15:19:52 +0200
parents 37fb240579e5
children 5fab4c43545b
files src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp
diffstat 2 files changed, 4 insertions(+), 16 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp	Wed Apr 22 12:34:09 2020 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp	Wed Apr 22 15:19:52 2020 +0200
@@ -125,18 +125,10 @@
         }
       }
 
-      // Try to mix the allocation into the mutator view:
-      if (ShenandoahAllowMixedAllocs) {
-        for (size_t c = _mutator_rightmost + 1; c > _mutator_leftmost; c--) {
-          size_t idx = c - 1;
-          if (is_mutator_free(idx)) {
-            HeapWord* result = try_allocate_in(_heap->get_region(idx), req, in_new_region);
-            if (result != NULL) {
-              return result;
-            }
-          }
-        }
-      }
+      // No dice. Do not try to mix mutator and GC allocations, because
+      // URWM moves due to GC allocations would expose unparsable mutator
+      // allocations.
+
       break;
     }
     default:
--- a/src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp	Wed Apr 22 12:34:09 2020 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp	Wed Apr 22 15:19:52 2020 +0200
@@ -211,10 +211,6 @@
   diagnostic(bool, ShenandoahElasticTLAB, true,                             \
           "Use Elastic TLABs with Shenandoah")                              \
                                                                             \
-  diagnostic(bool, ShenandoahAllowMixedAllocs, true,                        \
-          "Allow mixing mutator and collector allocations into a single "   \
-          "region. Some heuristics enable/disable it for their needs")      \
-                                                                            \
   experimental(uintx, ShenandoahEvacReserve, 5,                             \
           "How much of heap to reserve for evacuations. Larger values make "\
           "GC evacuate more live objects on every cycle, while leaving "    \