Disable concurrent marking/sweeping, and background compilation on ARMv5TE

runtime/vm/pages.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/pages.h"
 
 #include "platform/assert.h"
 #include "vm/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
 #include "vm/lockers.h"
 #include "vm/object.h"
 #include "vm/os_thread.h"
 #include "vm/safepoint.h"
 #include "vm/verified_memory.h"
 #include "vm/virtual_memory.h"
 
 namespace dart {
 
+// Disable concurrent sweeping by default on armv5te. The relevant
+// implementations are uniprocessors.
+#if defined(TARGET_ARCH_ARM_5TE)
+#define USING_CONCURRENT_SWEEP false
+#else
+#define USING_CONCURRENT_SWEEP true
+#endif
+
 DEFINE_FLAG(int, heap_growth_rate, 0,
             "The max number of pages the heap can grow at a time");
 DEFINE_FLAG(int, old_gen_growth_space_ratio, 20,
             "The desired maximum percentage of free space after old gen GC");
 DEFINE_FLAG(int, old_gen_growth_time_ratio, 3,
             "The desired maximum percentage of time spent in old gen GC");
 DEFINE_FLAG(int, old_gen_growth_rate, 280,
             "The max number of pages the old generation can grow at a time");
 DEFINE_FLAG(bool, print_free_list_before_gc, false,
             "Print free list statistics before a GC");
 DEFINE_FLAG(bool, print_free_list_after_gc, false,
             "Print free list statistics after a GC");
 DEFINE_FLAG(int, code_collection_interval_in_us, 30000000,
             "Time between attempts to collect unused code.");
 DEFINE_FLAG(bool, log_code_drop, false,
             "Emit a log message when pointers to unused code are dropped.");
 DEFINE_FLAG(bool, always_drop_code, false,
             "Always try to drop code if the function's usage counter is >= 0");
-DEFINE_FLAG(bool, concurrent_sweep, true,
+DEFINE_FLAG(bool, concurrent_sweep, USING_CONCURRENT_SWEEP,

[Ivan Posva, 2016/05/12 17:19:46]

ditto

[zra, 2016/05/12 19:54:21]

Done.

[zra, 2016/05/12 19:59:11]

That is, I moved concurrent_sweep. Moving the others, and changing some to
Release and Debug mode flags, broke the Product mode build a lot, so I'll make a
separate change to track everything down.

             "Concurrent sweep for old generation.");
 DEFINE_FLAG(bool, log_growth, false, "Log PageSpace growth policy decisions.");
 
 HeapPage* HeapPage::Initialize(VirtualMemory* memory, PageType type) {
   ASSERT(memory != NULL);
   ASSERT(memory->size() > VirtualMemory::PageSize());
   bool is_executable = (type == kExecutable);
   // Create the new page executable (RWX) only if we're not in W^X mode
   bool create_executable = !FLAG_write_protect_code && is_executable;
   if (!memory->Commit(create_executable)) {
@@ skipping 1187 matching lines @@
     return 0;
   } else {
     ASSERT(total_time >= gc_time);
     int result = static_cast<int>((static_cast<double>(gc_time) /
                                    static_cast<double>(total_time)) * 100);
     return result;
   }
 }
 
 }  // namespace dart