History log of /art/runtime/gc/collector/semi_space.h
Revision Date Author Comments
057d977aed600843dd4a617dca7098555d79110b 18-Feb-2017 Hiroshi Yamauchi <yamauchi@google.com> Always mark reference referents in transaction mode.

Fix a to-space invariant check failure in EnqueueFinalizerReferences.

Reference processing can be a problem and useless during transaction
because it's not easy to roll back what reference processing does and
there's no daemon threads running (in the unstarted runtime). To avoid
issues, always mark reference referents.

Add a do_atomic_update parameter to MarkHeapReference.

Bug: 35417063
Test: test-art-host with CC/CMS/SS.
Change-Id: If32eba8fca19ef86e5d13f7925d179c8aecb9e27
65f5f247a367af9d6b9ac63767b69ecf3ab079bc 19-Dec-2016 Hiroshi Yamauchi <yamauchi@google.com> Fix race condition btw DelayReferenceRefernent vs Reference.clear().

Rename IsMarkedHeapReference to IsNullOrMarkedHeapReference.

Move the null check from the caller of IsMarkedHeapReference into
IsNullOrMarkedHeapReference.

Make sure that the referent is only loaded once between the null
check and the IsMarked call.

Use a CAS in ConcurrentCopying::IsNullOrMarkedHeapReference when
called from DelayReferenceRefernent.

Bug: 33389022
Test: test-art-host without and with CC.

Change-Id: I20edab4dac2a4bb02dbb72af0f09de77b55ac08e
31e88225b2ef68e7f32f11186acf922c74ddabab 15-Oct-2016 Mathieu Chartier <mathieuc@google.com> Move most mirror:: args to ObjPtr

Fixed possible moving GC bugs in ClinitImageUpdate class.

Bug: 31113334

Test: test-art-host
Change-Id: I0bf6578553d58b944aaa17665f1350bdf5ed15ec
bdf7f1c3ab65ccb70f62db5ab31dba060632d458 31-Aug-2016 Andreas Gampe <agampe@google.com> ART: SHARED_REQUIRES to REQUIRES_SHARED

This coincides with the actual attribute name and upstream usage.
Preparation for deferring to libbase.

Test: m
Test: m test-art-host
Change-Id: Ia8986b5dfd926ba772bf00b0a35eaf83596d8518
8016bdee7ca1a066221a5d2fe5e60890de950a5b 16-Jun-2016 Mathieu Chartier <mathieuc@google.com> Use collector specific helper classes

Changed to use inner classes. Also changed some visitors to lambdas.

Bug: 29413717
Bug: 19534862

(cherry picked from commit a07f55913824ab4215a9a4f827fa9c043c0d44d9)

Change-Id: I631c8bfe5f795eda4623c5bb4f357f2dd12358e2
a07f55913824ab4215a9a4f827fa9c043c0d44d9 16-Jun-2016 Mathieu Chartier <mathieuc@google.com> Use collector specific helper classes

Changed to use inner classes. Also changed some visitors to lambdas.

Bug: 29413717
Bug: 19534862

Change-Id: I631c8bfe5f795eda4623c5bb4f357f2dd12358e2
a9d82fe8bc6960b565245b920e99107a824ca515 26-Jan-2016 Mathieu Chartier <mathieuc@google.com> Use mutator lock to guard adding and removing heap spaces

Too hard to add a new lock since dlmalloc ArtMoreCore requires
looping through the spaces while holding the allocator lock.

Bug: 22858531
Change-Id: Ieac2136da02c766b6795cd604a58798bee37ef2a
763a31ed7a2bfad22a9cb07f5301a71c0f97ca49 17-Nov-2015 Mathieu Chartier <mathieuc@google.com> Add immune spaces abstraction

ImmuneSpaces is a set of spaces which are not reclaimable by the GC in
the current collection. This set of spaces does not have requirements
about space adjacency like the old ImmuneRegion. ImmuneSpaces generates
the largest immune region for the GC. Since there is no requirement on
adjacency, it is possible to have multiple non-adjacent applicaton
image files.

For image spaces, we also look at the oat code which is normally after
the application image. In this case, we add the code as part of the
immune region. This is required to have both the boot image and the
zygote space be in the same immune region (for performance reasons).

Bug: 22858531

Change-Id: I5103b31c0e39ad63c594f5557fc848a3b288b43e
c62110668b7ceac450c3abcf279476139bf4e566 25-Jul-2015 Mathieu Chartier <mathieuc@google.com> Fix gcstress tests

We may visit the native roots multiple times (e.g. temp classes).
This used to not be handled by the SS GC but is now handle by
MarkObjectIfNotInToSpace.

Change-Id: I18226e20b36ace41c155ba4c3f54eac2244f524c
90443477f9a0061581c420775ce3b7eeae7468bc 17-Jul-2015 Mathieu Chartier <mathieuc@google.com> Move to newer clang annotations

Also enable -Wthread-safety-negative.

Changes:
Switch to capabilities and negative capabilities.

Future work:
Use capabilities to implement uninterruptible annotations to work
with AssertNoThreadSuspension.

Bug: 20072211

Change-Id: I42fcbe0300d98a831c89d1eff3ecd5a7e99ebf33
97509954404d031594b2ecbda607314d169d512e 13-Jul-2015 Mathieu Chartier <mathieuc@google.com> Clean up GC callbacks to be virtual methods

Change-Id: Ia08034a4e5931c4fcb329c3bd3c4b1f301135735
414369a2e3f23e1408fc1cbf4f623014bd95cb8f 04-May-2015 Mathieu Chartier <mathieuc@google.com> Add some more DISALLOW_COPY_AND_ASSIGN

May help prevent bugs maybe.

(cherry picked from commit 3130cdf29eb203be0c38d1107a65d920ec39c106)

Change-Id: Ie73d469dfcd078492ecb3aa28682b42707221202
3130cdf29eb203be0c38d1107a65d920ec39c106 04-May-2015 Mathieu Chartier <mathieuc@google.com> Add some more DISALLOW_COPY_AND_ASSIGN

May help prevent bugs maybe.

Change-Id: Ie73d469dfcd078492ecb3aa28682b42707221202
bb87e0f1a52de656bc77cb01cb887e51a0e5198b 03-Apr-2015 Mathieu Chartier <mathieuc@google.com> Refactor and improve GC root handling

Changed GcRoot to use compressed references. Changed root visiting to
use virtual functions instead of function pointers. Changed root visting
interface to be an array of roots instead of a single root at a time.
Added buffered root marking helper to avoid dispatch overhead.

Root marking seems a bit faster on EvaluateAndApplyChanges due to batch
marking. Pause times unaffected.

Mips64 is untested but might work, maybe.

Before:
MarkConcurrentRoots: Sum: 67.678ms 99% C.I. 2us-664.999us Avg: 161.138us Max: 671us

After:
MarkConcurrentRoots: Sum: 54.806ms 99% C.I. 2us-499.986us Avg: 136.333us Max: 602us

Bug: 19264997

Change-Id: I0a71ebb5928f205b9b3f7945b25db6489d5657ca
cb535da36915f9d10bec3880b46f1de1f7a69f22 23-Jan-2015 Mathieu Chartier <mathieuc@google.com> Change AtomicStack to use StackReference

Previously used Object*, using StackReference saves memory on 64 bit
devices.

Bug: 12935052
Bug: 17643507
Change-Id: I035878690054eeeb24d655a900b8f26c837703ff
e34fa1df67fbe0173b4ea9abddcc3ae3d0537037 14-Jan-2015 Mathieu Chartier <mathieuc@google.com> Print more info in MarkSweep::VerifyRoot

Refactored old root callback to use a new class called RootInfo.
RootInfo contains all the relevant info related to the root
associated with the callback. The MarkSweep::VerifyRoot function
now uses this info to print the StackVisitor's described location
if the GC root is of the type kRootJavaFrame.

Some other cleanup.

Example output:
E/art (12167): Tried to mark 0x123 not contained by any spaces
E/art (12167): Attempting see if it's a bad root
E/art (12167): Found invalid root: 0x123 with type RootJavaFrame
E/art (12167): Location=Visiting method
'void java.lang.Runtime.gc()' at dex PC 0xffffffff (native PC 0x0)
vreg=0

(cherry picked from commit 12f7423a2bb4bfab76700d84eb6d4338d211983a)

Bug: 18588862
Change-Id: Ic5a2781f704e931265ffb3621c2eab4b2e25f60f
12f7423a2bb4bfab76700d84eb6d4338d211983a 14-Jan-2015 Mathieu Chartier <mathieuc@google.com> Print more info in MarkSweep::VerifyRoot

Refactored old root callback to use a new class called RootInfo.
RootInfo contains all the relevant info related to the root
associated with the callback. The MarkSweep::VerifyRoot function
now uses this info to print the StackVisitor's described location
if the GC root is of the type kRootJavaFrame.

Some other cleanup.

Example output:
E/art (12167): Tried to mark 0x123 not contained by any spaces
E/art (12167): Attempting see if it's a bad root
E/art (12167): Found invalid root: 0x123 with type RootJavaFrame
E/art (12167): Location=Visiting method
'void java.lang.Runtime.gc()' at dex PC 0xffffffff (native PC 0x0)
vreg=0

Bug: 18588862
Change-Id: Ic5a2781f704e931265ffb3621c2eab4b2e25f60f
13735955f39b3b304c37d2b2840663c131262c18 08-Oct-2014 Ian Rogers <irogers@google.com> stdint types all the way!

Change-Id: I4e4ef3a2002fc59ebd9097087f150eaf3f2a7e08
b76cac637691c29daa9c44e493b5bc26346ed116 23-Jul-2014 Mathieu Chartier <mathieuc@google.com> Revert "Revert "Disable adding main and non moving spaces to immune region in GSS""

This reverts commit f85c2fb317399ab540854cd7551ac47690366543.
f85c2fb317399ab540854cd7551ac47690366543 22-Jul-2014 Mathieu Chartier <mathieuc@google.com> Revert "Disable adding main and non moving spaces to immune region in GSS"

Bug: 16399257

This reverts commit be0562fb14e6754ee932b8d9c97e2a6df3a91119.

Change-Id: I29e07a8fa1e972990e5bf1ddf8c9a3538ea5f9cf
be0562fb14e6754ee932b8d9c97e2a6df3a91119 14-Jul-2014 Mathieu Chartier <mathieuc@google.com> Disable adding main and non moving spaces to immune region in GSS

Disabled adding the main and non moving space to the immune region.
This will enable us to recycle bump pointer spaces for malloc space
-> malloc space compaction as well as collector transitions.

Also added logic for falling back to the non moving space, we may
copy objects there.

Refactored mod union table logic into MarkReachableObjects.

No measurable performance benefit or regression.

Bug: 14059466
Bug: 16291259

(cherry picked from commit 4c13a3ff475f206c4d0a86ee2595c45392fd942f)

Change-Id: I858b4fbddca888e164052ad247565a0bdbea68b5
4c13a3ff475f206c4d0a86ee2595c45392fd942f 14-Jul-2014 Mathieu Chartier <mathieuc@google.com> Disable adding main and non moving spaces to immune region in GSS

Disabled adding the main and non moving space to the immune region.
This will enable us to recycle bump pointer spaces for malloc space
-> malloc space compaction as well as collector transitions.

Also added logic for falling back to the non moving space, we may
copy objects there.

Refactored mod union table logic into MarkReachableObjects.

No measurable performance benefit or regression.

Bug: 14059466
Bug: 16291259

Change-Id: If663d9fdbde943b988173b7f6ac844e5f78a0327
e63db27db913f1a88e2095a1ee8239b2bb9124e8 16-Jul-2014 Ian Rogers <irogers@google.com> Break apart header files.

Create libart-gtest for common runtime and compiler gtest routines.
Rename CompilerCallbacksImpl that is quick compiler specific.
Rename trace clock source constants to not use the overloaded profiler term.

Change-Id: I4aac4bdc7e7850c68335f81e59a390133b54e933
308351ada0008b0cbe1a5afc31c302c975554ee4 15-Jun-2014 Mathieu Chartier <mathieuc@google.com> Change reference processing to use heap references.

Removes several SetReferents for updating moved referents. Cleaned
up other aspects of the code.

Change-Id: Ibcb4d713fadea617efee7e936352ddf77ff4c370
700a402244a1a423da4f3ba8032459f4b65fa18f 20-May-2014 Ian Rogers <irogers@google.com> Now we have a proper C++ library, use std::unique_ptr.

Also remove the Android.libcxx.mk and other bits of stlport compatibility
mechanics.

Change-Id: Icdf7188ba3c79cdf5617672c1cfd0a68ae596a61
507dfdd147c97bfbadebfd63584d094b6a4e7b47 16-May-2014 Ian Rogers <irogers@google.com> Compatibility layer to transition from UniquePtr to std::unique_ptr.

Use ART_WITH_STLPORT (enabled for the target) to cause the use of UniquePtr,
for the host switch to std::unique_ptr. For now the type remains called
UniquePtr.
Make dalvik compile with clang on the host, move its build to C++11.

Change-Id: I5ba8d2757904bc089ed62047ea03de3c0853fb12
eb8167a4f4d27fce0530f6724ab8032610cd146b 08-May-2014 Mathieu Chartier <mathieuc@google.com> Add Handle/HandleScope and delete SirtRef.

Delete SirtRef and replaced it with Handle. Handles are value types
which wrap around StackReference*.

Renamed StackIndirectReferenceTable to HandleScope.

Added a scoped handle wrapper which wraps around an Object** and
restores it in its destructor.

Renamed Handle::get -> Get.

Bug: 8473721

Change-Id: Idbfebd4f35af629f0f43931b7c5184b334822c7a
24faeb23de9aa3038cac6655b575a4b991a6add4 07-May-2014 Hiroshi Yamauchi <yamauchi@google.com> Trigger GSS whole-heap collection based on large object allocations.

This is to avoid a large amount of accumulated dead large objects. For
example, in Maps, there was a case where ~100 MB of large objects were
accumulated before collected.

Bug: 11650816
Change-Id: Ie0ab1561282902a823e110d45f87146ba41fe6f8
0651d41e41341fb2e9ef3ee41dc1f1bfc832dbbb 29-Apr-2014 Mathieu Chartier <mathieuc@google.com> Add thread unsafe allocation methods to spaces.

Used by SS/GSS collectors since these run with mutators suspended and
only allocate from a single thread. Added AllocThreadUnsafe to
BumpPointerSpace and RosAllocSpace. Added AllocThreadUnsafe which uses
current runs as thread local runs for a thread unsafe allocation.
Added code to revoke current runs which are the same idx as thread
local runs.

Changed:
The number of thread local runs in each thread is now the the number
of thread local runs in RosAlloc instead of the number of size
brackets.

Total GC time / time on EvaluateAndApplyChanges.
TLAB SS:
Before: 36.7s / 7254
After: 16.1s / 4837

TLAB GSS:
Before: 6.9s / 3973
After: 5.7s / 3778

Bug: 8981901

Change-Id: Id1d264ade3799f431bf7ebbdcca6146aefbeb632
b0fa5dc7769c1e054032f39de0a3f6d6dd06f8cf 29-Apr-2014 Ian Rogers <irogers@google.com> Force inlining on trivial accessors.

Make volatility for GetFieldObject a template parameter.
Move some trivial mirror::String routines to a -inl.h.

Bug: 14285442

Change-Id: Ie23b11d4f18cb15a62c3bbb42837a8aaf6b68f92
6f365cc033654a5a3b45eaa1379d4b5f156b0cee 23-Apr-2014 Mathieu Chartier <mathieuc@google.com> Enable concurrent sweeping for non-concurrent GC.

Refactored the GarbageCollector to let all of the phases be run by
the collector's RunPhases virtual method. This lets the GC decide
which phases should be concurrent and reduces how much baked in GC
logic resides in GarbageCollector.

Enabled concurrent sweeping in the semi space and non concurrent
mark sweep GCs. Changed the semi-space collector to have a swap semi
spaces boolean which can be changed with a setter.

Fixed tests to pass with GSS collector, there was an error related to
the large object space limit.

Before (EvaluateAndApplyChanges):
GSS paused GC time 7.81s/7.81s, score: 3920

After (EvaluateAndApplyChanges):
GSS paused GC time 6.94s/7.71s, score: 3900

Benchmark score doesn't go up since the GC happens in the allocating
thread. There is a slight reduction in pause times experienced by
other threads (0.8s total).

Added options for pre sweeping GC heap verification and pre sweeping
rosalloc verification.

Bug: 14226004
Bug: 14250892
Bug: 14386356

Change-Id: Ib557d0590c1ed82a639d0f0281ba67cf8cae938c
4db7449c0065971ec3a64ca04aeb64cfd2e802f0 23-Apr-2014 Hiroshi Yamauchi <yamauchi@google.com> Improve GSS reference processing.

Support the case where the reference object is in the free list space
and the referent object is in the bump pointer space at a bump pointer
space collection.

Bug: 11650816
Change-Id: If98b08edc9e37351c74ee07cb3f2d30c2b4d0056
bbd695c71e0bf518f582e84524e1cdeb3de3896c 16-Apr-2014 Mathieu Chartier <mathieuc@google.com> Replace ObjectSet with LargeObjectBitmap.

Speeds up large object marking since large objects no longer required
a lock. Changed the GCs to use the heap bitmap for marking objects
which aren't in the fast path. This eliminates the need for a
MarkLargeObject function.

Maps before (10 GC iterations):
Mean partial time: 180ms
Mean sticky time: 151ms

Maps after:
Mean partial time: 161ms
Mean sticky time: 101ms

Note: the GC durations are long due to recent ergonomic changes and
because the fast bulk free hasn't yet been enabled. Over 50% of the
GC time is spent in RosAllocSpace::FreeList.

Bug: 13571028

Change-Id: Id8f94718aeaa13052672ccbae1e8edf77d653f62
4d7f61d44a732cfbc8573e5d93364983fd746888 17-Apr-2014 Mathieu Chartier <mathieuc@google.com> Use non volatile lock words in semispace collector.

GSS FormulaEvaluationActions.EvaluateAndApplyChanges:
Before GC time: 9.1s
After GC time: 7.98s

Fixed timing logger errors.

Change-Id: I4193c6ccbbbe7a7220dfaabbf3472a5dcebae616
a8e8f9c0a8e259a807d7b99a148d14104c24209d 09-Apr-2014 Mathieu Chartier <mathieuc@google.com> Refactor space bitmap to support different alignments.

Required for:
Using space bitmaps instead of std::set in mod union table +
remembered set.
Using a bitmap instead of set for large object marking.

Bug: 13571028

Change-Id: Id024e9563d4ca4278f79607cdb2f81895121b113
df386c551405ce9668e827584f744c6f098761fa 09-Apr-2014 Hiroshi Yamauchi <yamauchi@google.com> GSS: Fix the bump pointer space only collection.

Fixes b/13912464 where the clear soft reference behavior accidentally
disabled the bump pointer space only collection.

Changed the collector name so that the GC logs would indicate the
generational mode and the collection mode.

Peformance enhancement: instead of triggering the whole heap
collection every 5 collections, count the bytes promoted since the
last whole heap collection and use it to decide when to trigger the
whole heap collection. This improves MemAllocTest by 5-10% (N4 and
host).

Bug: 13912464
Bug: 11650816
Bug: 9986565
Change-Id: I653a0dca62a8b54adf69abe2940a41eac70f809b
4aeec176eaf11fe03f342aadcbb79142230270ed 28-Mar-2014 Mathieu Chartier <mathieuc@google.com> Refactor some GC code.

Reduced amount of code in mark sweep / semi space by moving
common logic to garbage_collector.cc. Cleaned up mod union tables
and deleted an unused implementation.

Change-Id: I4bcc6ba41afd96d230cfbaf4d6636f37c52e37ea
3b05e9ba874449dbff65b01b8781001f7d93eea6 25-Mar-2014 Mathieu Chartier <mathieuc@google.com> Add missing debugger root visiting.

Bug: 13634574
Change-Id: I2a76f6c43f1d0ad1922f06deb40a71ff651129fd
407f702da4f867c074fc3c8c688b8f8c32279eff 18-Feb-2014 Mathieu Chartier <mathieuc@google.com> Refactor object reference visiting logic.

Refactored the reference visiting logic to be in mirror::Object
instead of MarkSweep.

Change-Id: I773249478dc463d83b465e85c2402320488577c0
0e54cd0d8fc635d3dc8bf88a465fdade151a098f 20-Mar-2014 Mathieu Chartier <mathieuc@google.com> Refactor and optimize GC code.

Fixed the reference cache mod union table, and re-enabled it by
default. Added a boolean flag to count how many null objects,
immune, fast path, slow path objects we marked.

Slight speedup in mark stack processing, large speedup in image mod
union table scanning.
EvaluateAndApplyChanges Before:
Process mark stack time for full GC only:
12.464089s, 12.357870s, 12.538028s
Time spent marking mod image union table ~240ms.
After:
Process mark stack time: 12.299375s, 12.217142s, 12.187076s
Time spent marking mod image union table ~40ms.

TODO: Refactor reference visiting logic into mirror::Object.

Change-Id: I91889ded9d3f2bf127bc0051c1b1ff77e792e94f
c93c530efc175954160c3834c93961a1a946a35a 21-Mar-2014 Hiroshi Yamauchi <yamauchi@google.com> Revoke rosalloc thread-local buffers at the checkpoint.

In the mark sweep collector, rosalloc thread-local buffers were
revoked during the pause. Now, they are revoked at the thread
checkpoint, as opposed to during the pause, which appears to help
reduce the pause time.

In Ritz MemAllocTest, the average sticky pause time went down ~20%
(925 us -> 724 us).

Bug: 13394464
Bug: 9986565
Change-Id: I104992a11b46d59264c0b9aa2db82b1ccf2826bc
3e41780cb3bcade3b724908e00443a9caf6977ef 20-Mar-2014 Hiroshi Yamauchi <yamauchi@google.com> Refactor the garbage collector driver (GarbageCollector::Run).

Bug: 12687968

Change-Id: Ifc9ee86249f7938f51495ea1498cf0f7853a27e8
38e68e9978236db87c9008bbe47db80525d2fa16 07-Mar-2014 Hiroshi Yamauchi <yamauchi@google.com> Use the card table to speed up the GSS collector.

Scan only dirty cards, as opposed to the whole space, to find
references from the non-moving spaces to the bump pointer spaces at
bump pointer space only collections.

With this change, the Ritz MemAllocTest speeds up by 8-10% on host and
2-3% on N4. The Ritz EvaluateFibonacci speeds up by 8% and its average
pause time is reduced by 43% on N4.

Bug: 11650816
Change-Id: I1eefe75776bc37e24673b301ffa65a25f9bd4cde
8d562103c3a3452fb15ef4b1c64df767b70507a4 13-Mar-2014 Mathieu Chartier <mathieuc@google.com> Refactor immune region logic into its own file.

Added immune_region.cc/.h in the collector directory. Changed the
functionality to no longer assume spaces are added to immune region
in ascending order.

Change-Id: Id1d643b3849ad2695e8a151dbbb74a5035644472
6fac447555dc94a935b78198479cce645c837b89 26-Feb-2014 Ian Rogers <irogers@google.com> Make allocations report usable size.

Work-in-progress to allow arrays to fill usable size. Bug: 13028925.
Use C++11's override keyword on GCC >= 2.7 to ensure that we override GC and
allocator methods.
Move initial mirror::Class set up into a Functor so that all allocated objects
have non-zero sizes. Use this property to assert that all objects are never
larger than their usable size.
Other bits of GC related clean-up, missing initialization, missing use of
const, hot methods in .cc files, "unimplemented" functions that fail at
runtime in header files, reducing header file includes, move valgrind's space
into its own files, reduce number of array allocation routines.

Change-Id: Id5760041a2d7f94dcaf17ec760f6095ec75dadaa
3bb57c7b41bf5419fe895e7aa664d8d430205ba8 18-Feb-2014 Mathieu Chartier <mathieuc@google.com> Change ProcessReferences to not use RecursiveMarkObject.

Calling ProcessMarkStack in RecursiveMarkObject caused a lot of
overhead due to timing logger splits. Changed the logic to be the
same as prior to the reference queue refactoring which involves
calling process mark stack after preserving soft references and
enqueueing finalizer references.

FinalizingGC longest pause is reduced by around 1/2 down to ~300ms.
Benchmark score ~400000 -> ~600000.

Also changed the timing logger splits in the GC to have (Paused) if
the split is a paused part of the GC.

Bug: 12129382

Change-Id: I7476d4f23670b19d70738e2fd48e37ec2f57e9f4
815873ecc312b1d231acce71e1a16f42cdaf09f2 14-Feb-2014 Mathieu Chartier <mathieuc@google.com> Change root visitor to use Object**.

Simplifies code and improves the performance of root visiting since
we usually don't need to check to see if the object moved.

Change-Id: Iba998f5a15ae1fa1b53ca5226dd2168a411196cf
ad35d904c0b835f7e005c471d2c6b18b84894595 12-Feb-2014 Mathieu Chartier <mathieuc@google.com> Avoid unnecessarily dirtying pages in SemiSpace collector.

Added a special version of memcpy which has handling to avoid dirty
pages for objects which are larger than one page. No non noise GC
performance regression measured on ritzperf benchmark. Seems to save
4k to 148k memory per app on AOSP mako.

Bug: 10802951
Change-Id: I5976c83643e06beebf5c86a65c584bf7c1ab1e2e
83c8ee000d525017ead8753fce6bc1020249b96a 28-Jan-2014 Mathieu Chartier <mathieuc@google.com> Add root types and thread id to root visiting.

Enables us to pass the root type and thread id to hprof.

Bug: 12680863
Change-Id: I6a0f1f9e3aa8f9b4033d695818ae7ca3460d67cb
ef7d42fca18c16fbaf103822ad16f23246e2905d 06-Jan-2014 Ian Rogers <irogers@google.com> Object model changes to support 64bit.

Modify mirror objects so that references between them use an ObjectReference
value type rather than an Object* so that functionality to compress larger
references can be captured in the ObjectRefererence implementation.
ObjectReferences are 32bit and all other aspects of object layout remain as
they are currently.

Expand fields in objects holding pointers so they can hold 64bit pointers. Its
expected the size of these will come down by improving where we hold compiler
meta-data.
Stub out x86_64 architecture specific runtime implementation.
Modify OutputStream so that reads and writes are of unsigned quantities.
Make the use of portable or quick code more explicit.
Templatize AtomicInteger to support more than just int32_t as a type.
Add missing, and fix issues relating to, missing annotalysis information on the
mutator lock.
Refactor and share implementations for array copy between System and uses
elsewhere in the runtime.
Fix numerous 64bit build issues.

Change-Id: I1a5694c251a42c9eff71084dfdd4b51fff716822
a1602f28c0e3127ad511712d4b08db89737ae901 14-Jan-2014 Mathieu Chartier <mathieuc@google.com> Add zygote space as its own space type.

Helps prevent errors caused from doing invalid operations on the
old alloc space.

Removed some duplicated code in mark_sweep.cc and semi_space.cc.

Change-Id: I67a772cab30d698744c918aad581053f282a4a99
6f4ffe41649f1e6381e8cda087ad3749206806e5 13-Jan-2014 Hiroshi Yamauchi <yamauchi@google.com> Improve the generational mode.

- Turn the compile-time flags for generational mode into a command
line flag.

- In the generational mode, always collect the whole heap, as opposed
to the bump pointer space only, if a collection is an explicit,
native allocation-triggered or last attempt one.

Change-Id: I7a14a707cc47e6e3aa4a3292db62533409f17563
05e713a3a009a0825826ce6d494582fcd6dd6a8d 09-Jan-2014 Hiroshi Yamauchi <yamauchi@google.com> Bump pointer space only collection.

Add a mode of collection that collects only the bump pointer spaces,
as opposed to the whole heap. It's disabled behind a flag.

TODO: It still scans the entire non-moving space to look for
inter-space references. Use a card table like technique to limit the
scope of scanning and speed it up.

Bug: 11650816
Change-Id: I56cb11e78e47a578bff644e6e6c63d978cfedf39
5dc08a680696554ffc76d58dd591b23e79f5b5a1 10-Jan-2014 Mathieu Chartier <mathieuc@google.com> Fix ART debug build boot.

Some of the checks were no longer valid after the zygote bin packing.

Bug: 12480317
Change-Id: Iaa169b0aafe9fec06e75e9b58a3de28aa70a9421
85a43c055fcdc366293c61df6f65e586d6967841 08-Jan-2014 Mathieu Chartier <mathieuc@google.com> Bin packing the zygote (best fit).

We now use bin packing to fill holes in the non movable space with
objects from the bump pointer space when we create the zygote.

Zygote space PSS reduction on AOSP: ~300k.
Zygote size on AOSP: 2121040 bytes -> 1597944 bytes.

Deleted some unreachable code.

Bug: 11902311

Change-Id: Idc957d69e93b3a941e0c298d47a21b73526dd286
e6da9af8dfe0a3e3fbc2be700554f6478380e7b9 16-Dec-2013 Mathieu Chartier <mathieuc@google.com> 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
4b1782f1c1af136a18f2886e76ef32216c3db3e4 06-Dec-2013 Hiroshi Yamauchi <yamauchi@google.com> A simple promotion-like mechanism.

If enabled, this mechanism moves objects that survive the first
semi-space copying collection to the non-moving space.

Bug: 11650816
Change-Id: Ia2fc902d08dc983449416f420a39449f9ed96255
39e3261168e7761fea6d873494d7c5d191285791 13-Nov-2013 Mathieu Chartier <mathieuc@google.com> Refactor reference queues.

Refactored the reference queue processing to reside in the heap code.
This removes significant code duplication in the semispace and
marksweep garbage collectors.

Changed the soft reference behaviour to preserve all soft references
unless the GC requires them to be cleared to avoid an out of memory
error. It may be worth investigating a better heuristic in the
future to preserve soft references by LRU order.

Change-Id: I1f3ff5bd4b3c5149271f4bb4fc94ba199e2f9bc2
590fee9e8972f872301c2d16a575d579ee564bee 13-Sep-2013 Mathieu Chartier <mathieuc@google.com> Compacting collector.

The compacting collector is currently similar to semispace. It works by
copying objects back and forth between two bump pointer spaces. There
are types of objects which are "non-movable" due to current runtime
limitations. These are Classes, Methods, and Fields.

Bump pointer spaces are a new type of continuous alloc space which have
no lock in the allocation code path. When you allocate from these it uses
atomic operations to increase an index. Traversing the objects in the bump
pointer space relies on Object::SizeOf matching the allocated size exactly.

Runtime changes:
JNI::GetArrayElements returns copies objects if you attempt to get the
backing data of a movable array. For GetArrayElementsCritical, we return
direct backing storage for any types of arrays, but temporarily disable
the GC until the critical region is completed.

Added a new runtime call called VisitObjects, this is used in place of
the old pattern which was flushing the allocation stack and walking
the bitmaps.

Changed image writer to be compaction safe and use object monitor word
for forwarding addresses.

Added a bunch of added SIRTs to ClassLinker, MethodLinker, etc..

TODO: Enable switching allocators, compacting on background, etc..

Bug: 8981901

Change-Id: I3c886fd322a6eef2b99388d19a765042ec26ab99