Background compaction support.
When the process state changes to a state which does not perceives
jank, we copy from the main free-list backed allocation space to
the bump pointer space and enable the semispace allocator.
When we transition back to foreground, we copy back to a free-list
backed space.
Create a seperate non-moving space which only holds non-movable
objects. This enables us to quickly wipe the current alloc space
(DlMalloc / RosAlloc) when we transition to background.
Added multiple alloc space support to the sticky mark sweep GC.
Added a -XX:BackgroundGC option which lets you specify
which GC to use for background apps. Passing in
-XX:BackgroundGC=SS makes the heap compact the heap for apps which
do not perceive jank.
Results:
Simple background foreground test:
0. Reboot phone, unlock.
1. Open browser, click on home.
2. Open calculator, click on home.
3. Open calendar, click on home.
4. Open camera, click on home.
5. Open clock, click on home.
6. adb shell dumpsys meminfo
PSS Normal ART:
Sample 1:
88468 kB: Dalvik
3188 kB: Dalvik Other
Sample 2:
81125 kB: Dalvik
3080 kB: Dalvik Other
PSS Dalvik:
Total PSS by category:
Sample 1:
81033 kB: Dalvik
27787 kB: Dalvik Other
Sample 2:
81901 kB: Dalvik
28869 kB: Dalvik Other
PSS ART + Background Compaction:
Sample 1:
71014 kB: Dalvik
1412 kB: Dalvik Other
Sample 2:
73859 kB: Dalvik
1400 kB: Dalvik Other
Dalvik other reduction can be explained by less deep allocation
stacks / less live bitmaps / less dirty cards.
TODO improvements: Recycle mem-maps which are unused in the current
state. Not hardcode 64 MB capacity of non movable space (avoid
returning linear alloc nightmares). Figure out ways to deal with low
virtual address memory problems.
Bug: 8981901
Change-Id: Ib235d03f45548ffc08a06b8ae57bf5bada49d6f3
diff --git a/runtime/gc/space/malloc_space.cc b/runtime/gc/space/malloc_space.cc
index 2727431..31d878c 100644
--- a/runtime/gc/space/malloc_space.cc
+++ b/runtime/gc/space/malloc_space.cc
@@ -81,10 +81,9 @@
std::string error_msg;
MemMap* mem_map = MemMap::MapAnonymous(name.c_str(), requested_begin, *capacity,
PROT_READ | PROT_WRITE, &error_msg);
- if (mem_map == NULL) {
+ if (mem_map == nullptr) {
LOG(ERROR) << "Failed to allocate pages for alloc space (" << name << ") of size "
<< PrettySize(*capacity) << ": " << error_msg;
- return NULL;
}
return mem_map;
}
@@ -190,9 +189,6 @@
size_t size = RoundUp(Size(), kPageSize);
// Trim the heap so that we minimize the size of the Zygote space.
Trim();
- // TODO: Not hardcode these in?
- const size_t starting_size = kPageSize;
- const size_t initial_size = 2 * MB;
// Remaining size is for the new alloc space.
const size_t growth_limit = growth_limit_ - size;
const size_t capacity = Capacity() - size;
@@ -203,6 +199,10 @@
<< "Capacity " << Capacity();
SetGrowthLimit(RoundUp(size, kPageSize));
SetFootprintLimit(RoundUp(size, kPageSize));
+
+ // TODO: Not hardcode these in?
+ const size_t starting_size = kPageSize;
+ const size_t initial_size = 2 * MB;
// FIXME: Do we need reference counted pointers here?
// Make the two spaces share the same mark bitmaps since the bitmaps span both of the spaces.
VLOG(heap) << "Creating new AllocSpace: ";