Commits · b9b4da5a00270b8f9fc02e5730ddb5bda85c2b41 · Linshizhi / V8

12 Apr, 2021 1 commit

Allowing map word to be used for other state in GC header. · 5e0b94c4

Wenyu Zhao authored 3 years ago

This CL adds features to pack/unpack map words.

Currently V8 cannot store extra metadata in object headers -- because V8
objects do not have a proper header, but only a map pointer at the start
of the object. To store per-object metadata like marking data, a side
table is required as the per-object metadata storage.

This CL enables V8 to use higher unused bits in a 64-bit map word as
per-object metadata storage. Map pointer stores come with an extra step
to encode the metadata into the pointer (we call it "map packing").
Map pointer loads will also remove the metadata bits as well (we call it
"map packing").

Since the map word is no longer a valid pointer after packing, we also
change the tag of the packed map word to make it looks like a Smi. This
helps various GC and barrier code to correctly skip them instead of
blindly dereferencing this invalid pointer.

A ninja flag `v8_enable_map_packing` is provided to turn this
map-packing feature on and off. It is disabled by default.

* Only works on x64 platform, with `v8_enable_pointer_compression`
set to `false`

Bug: v8:11624
Change-Id: Ia2bdf79553945e5fc0b0874c87803d2cc733e073
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2247561Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73915}

5e0b94c4

04 May, 2020 1 commit

[offthread] Allow off-thread fillers · 457aa07b

Leszek Swirski authored 4 years ago

Create a static version of Heap::CreateFillerObjectAt which can't clear
slots (as it doesn't access the heap), but can therefore be used in the
OffThreadHeap. This will allow off-thread deserialization in the future.

Bug: chromium:1075999
Change-Id: I4b4046ccfaa51822350ff7c384dbe33e621ed4f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2170230
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67528}

457aa07b

27 May, 2019 3 commits

Reland "[typedarray] Move external/data pointer to JSTypedArray." · 70bd7cf0

Benedikt Meurer authored 5 years ago

This is a reland of 4b86fea5 with
copy&paste typo in CodeStubAssembler::AllocateByteArray() fixed
(bug led to holes in new space, which was crashing reproducibly
on the ia32 bot).

Original change's description:
> [typedarray] Move external/data pointer to JSTypedArray.
>
> As the next step in supporting huge typed arrays in V8, this moves the
> external/data pointer from the FixedTypedArrayBase backing store to the
> JSTypedArray instance itself, and replaces the special backing stores
> with a plain ByteArray (removing all the code for the FixedTypedArrayBase
> class hierarchy). By doing so, we can drastically simplify the system
> around typed arrays.
>
> Note: Several places in the code base used to check the instance type
> of the elements backing store of a JSTypedArray instead of checking the
> elements kind on the JSTypedArray map directly. Those had to be fixed,
> since the backing store is now always a ByteArray.
>
> Drive-by-fix: Move all the typed elements access related code into the
> elements.cc file to properly encapsulate the accesses.
>
> Doc: http://doc/1Z-wM2qwvAuxH46e9ivtkYvKzzwYZg8ymm0x0wJaomow
> Bug: chromium:951196, chromium:965583, v8:4153, v8:7881, v8:9183
> Change-Id: I8cc06b190c53e34155000b4560f5f3ef40621646
> Cq-Include-Trybots: luci.chromium.try:linux-rel,win7-rel
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627535
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61855}

Tbr: petermarshall@chromium.org
Bug: chromium:951196, chromium:965583, v8:4153, v8:7881, v8:9183
Change-Id: I87fcdb28532c5f08cc227332a4d59546cb423810
Cq-Include-Trybots: luci.chromium.try:linux-rel, win7-rel
Cq-Include-Trybots: luci.v8.try:v8_linux_shared_compile_rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1631592Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61864}

70bd7cf0

Revert "[typedarray] Move external/data pointer to JSTypedArray." · e4db146a

Clemens Hammacher authored 5 years ago

This reverts commit 4b86fea5.

Reason for revert: Fails on linux shared: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20shared/31045

Original change's description:
> [typedarray] Move external/data pointer to JSTypedArray.
> 
> As the next step in supporting huge typed arrays in V8, this moves the
> external/data pointer from the FixedTypedArrayBase backing store to the
> JSTypedArray instance itself, and replaces the special backing stores
> with a plain ByteArray (removing all the code for the FixedTypedArrayBase
> class hierarchy). By doing so, we can drastically simplify the system
> around typed arrays.
> 
> Note: Several places in the code base used to check the instance type
> of the elements backing store of a JSTypedArray instead of checking the
> elements kind on the JSTypedArray map directly. Those had to be fixed,
> since the backing store is now always a ByteArray.
> 
> Drive-by-fix: Move all the typed elements access related code into the
> elements.cc file to properly encapsulate the accesses.
> 
> Doc: http://doc/1Z-wM2qwvAuxH46e9ivtkYvKzzwYZg8ymm0x0wJaomow
> Bug: chromium:951196, chromium:965583, v8:4153, v8:7881, v8:9183
> Change-Id: I8cc06b190c53e34155000b4560f5f3ef40621646
> Cq-Include-Trybots: luci.chromium.try:linux-rel,win7-rel
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627535
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61855}

TBR=ulan@chromium.org,yangguo@chromium.org,titzer@chromium.org,sigurds@chromium.org,petermarshall@chromium.org,bmeurer@chromium.org,szuend@chromium.org

Change-Id: I0bc1f935de6063acf75a0f4bb8c0ba67428603fd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:951196, chromium:965583, v8:4153, v8:7881, v8:9183
Cq-Include-Trybots: luci.chromium.try:linux-rel, win7-rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1631427Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61856}

e4db146a

[typedarray] Move external/data pointer to JSTypedArray. · 4b86fea5

Benedikt Meurer authored 5 years ago

As the next step in supporting huge typed arrays in V8, this moves the
external/data pointer from the FixedTypedArrayBase backing store to the
JSTypedArray instance itself, and replaces the special backing stores
with a plain ByteArray (removing all the code for the FixedTypedArrayBase
class hierarchy). By doing so, we can drastically simplify the system
around typed arrays.

Note: Several places in the code base used to check the instance type
of the elements backing store of a JSTypedArray instead of checking the
elements kind on the JSTypedArray map directly. Those had to be fixed,
since the backing store is now always a ByteArray.

Drive-by-fix: Move all the typed elements access related code into the
elements.cc file to properly encapsulate the accesses.

Doc: http://doc/1Z-wM2qwvAuxH46e9ivtkYvKzzwYZg8ymm0x0wJaomow
Bug: chromium:951196, chromium:965583, v8:4153, v8:7881, v8:9183
Change-Id: I8cc06b190c53e34155000b4560f5f3ef40621646
Cq-Include-Trybots: luci.chromium.try:linux-rel,win7-rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627535
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61855}

4b86fea5

24 May, 2019 1 commit

Move remaining files in src/ · f9a88acb

Yang Guo authored 5 years ago

TBR=mvstanton@chromium.org,neis@chromium.org,ahaas@chromium.org

Bug: v8:9247
Change-Id: I5433c863a54f3412d73df0d38aba3fdbcfac7ebe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627973
Commit-Queue: Yang Guo <yangguo@chromium.org>
Auto-Submit: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61830}

f9a88acb

23 May, 2019 2 commits

Move more relevant files to src/objects · a0c37974

Yang Guo authored 5 years ago

TBR=bmeurer@chromium.org,leszeks@chromium.org

Bug: v8:9247
Change-Id: I8d14d0192ea8c705f8274e8e61a162531826edb6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624220Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61769}

a0c37974

[cleanup] Avoid {Object::operator->} · 878ccb33

Clemens Hammacher authored 5 years ago

This CL was generated by an automatic clang AST rewriter using this
matcher expression:

  callExpr(
    callee(
      cxxMethodDecl(
        hasName("operator->"),
        ofClass(isSameOrDerivedFrom("v8::internal::Object"))
      )
    ),
    argumentCountIs(1)
  )

The "->" at the expression location was then rewritten to ".".

R=jkummerow@chromium.org
TBR=mstarzinger@chromium.org,verwaest@chromium.org,yangguo@chromium.org

Bug: v8:9183, v8:3770
No-Try: true
No-Tree-Checks: true
Change-Id: I0a7ecabdeafe51d0cf427f5280af0c7cab96869e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624209Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61764}

878ccb33

20 May, 2019 1 commit

Move relevant files to src/objects · 8ad6b335

Yang Guo authored 5 years ago

Code that is being moved primarily deal with layout of a JSObject,
accessing properties and elements, and map transitions.

NOTREECHECKS=true
NOTRY=true

Bug: v8:9247
Change-Id: Ibce5d5926ac4021c8d40c4dd109948775ce1da58
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1613994
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61638}

8ad6b335

08 May, 2019 1 commit

Reland "[heap] Set read-only space's and its pages' heap_ to null." · b672d089

Maciej Goszczycki authored 5 years ago

Seems like the CodeBuilder CL actually caused this.

This is a reland of 964edc25

Original change's description:
> [heap] Set read-only space's and its pages' heap_ to null.
>
> Various small changes are required to enable this.
>
> HeapObject::GetReadOnlyRoots no longer uses the Space's heap when
> possible (see comment in ReadOnlyHeap::GetReadOnlyRoots definition).
> This requires that ReadOnlyRoots be construct-able using a raw pointer
> to the read-only space's roots array.
>
> Global read-only heap state is now cleared by tests where appropriate
> and extra DCHECKs in ReadOnlyHeap::SetUp should make catching future
> issues easier.
>
> String padding is now always cleared just before read-only space is
> sealed when not deserializing.
>
> Change-Id: I7d1db1c11567be5df06ff7066f3a699125f8b372
> Bug: v8:7464
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1535830
> Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61188}

Bug: v8:7464
Change-Id: If75bbd16c2e2af5b80cd60811dfd7866f8be8309
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1599186
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61323}

b672d089

03 May, 2019 1 commit

Revert "[heap] Set read-only space's and its pages' heap_ to null." · fa4b433f

Maciej Goszczycki authored 5 years ago

This reverts commit 964edc25.

Reason for revert: chromium:959190

Original change's description:
> [heap] Set read-only space's and its pages' heap_ to null.
>
> Various small changes are required to enable this.
>
> HeapObject::GetReadOnlyRoots no longer uses the Space's heap when
> possible (see comment in ReadOnlyHeap::GetReadOnlyRoots definition).
> This requires that ReadOnlyRoots be construct-able using a raw pointer
> to the read-only space's roots array.
>
> Global read-only heap state is now cleared by tests where appropriate
> and extra DCHECKs in ReadOnlyHeap::SetUp should make catching future
> issues easier.
>
> String padding is now always cleared just before read-only space is
> sealed when not deserializing.
>
> Change-Id: I7d1db1c11567be5df06ff7066f3a699125f8b372
> Bug: v8:7464
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1535830
> Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61188}

TBR=ulan@chromium.org,hpayer@chromium.org,delphick@chromium.org,goszczycki@google.com

Change-Id: I53cecf3976dfeabae309040313351385f651f010
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7464, chromium:959190
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1591608Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61217}

fa4b433f

02 May, 2019 1 commit

[heap] Set read-only space's and its pages' heap_ to null. · 964edc25

Maciej Goszczycki authored 5 years ago

Various small changes are required to enable this.

HeapObject::GetReadOnlyRoots no longer uses the Space's heap when
possible (see comment in ReadOnlyHeap::GetReadOnlyRoots definition).
This requires that ReadOnlyRoots be construct-able using a raw pointer
to the read-only space's roots array.

Global read-only heap state is now cleared by tests where appropriate
and extra DCHECKs in ReadOnlyHeap::SetUp should make catching future
issues easier.

String padding is now always cleared just before read-only space is
sealed when not deserializing.

Change-Id: I7d1db1c11567be5df06ff7066f3a699125f8b372
Bug: v8:7464
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1535830
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61188}

964edc25

15 Feb, 2019 1 commit

[cleanup] #include heap-inl.h less often · 6cac1382

Jakob Kummerow authored 6 years ago

This takes heap-inl.h out of the "Giant Include Cluster".
Naturally, that means adding a bunch of explicit includes
in a bunch of places that relied on transitively including
them before.
As of this patch, no header file outside src/heap/ includes
heap-inl.h.

Bug: v8:8562,v8:8499
Change-Id: I65fa763f90e66afc30d105b9277792721f05a6d4
Reviewed-on: https://chromium-review.googlesource.com/c/1459659
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59617}

6cac1382

16 Oct, 2018 1 commit

Clarify roots iteration · 08b8e0ff

Dan Elphick authored 6 years ago

Change Heap::IterateStrongRoots to never iterate the read-only roots. In
doing so remove VISIT_ALL_BUT_READ_ONLY and
VISIT_ONLY_STRONG_FOR_SERIALIZATION. All such uses should now use
VISIT_ALL and VISIT_ONLY_STRONG. Where ReadOnlyRoots iteration is
required, this adds ReadOnlyRoots(isolate)->Iterate() at the call site.

Add new begin, end, strong_mutable_roots_begin and
strong_mutable_roots_end methods to RootsTable and try and make the
existing uses a little more consistent.

Bug: v8:8191
Change-Id: Ie9d0f9e5186db418428e2fafd38432b0bd879daa
Reviewed-on: https://chromium-review.googlesource.com/c/1278500
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56672}

08b8e0ff

11 Oct, 2018 1 commit

[ptr-compr] Move Heap::root() to Isolate · 54855b67

Igor Sheludko authored 6 years ago

... and Heap::root_handle() to RootsTable.

This is a preliminary step before moving IsolateData object from Heap to Isolate
which is required for pointer-compression friendly heap layout.

Bug: v8:8182
Change-Id: Ideacc1c9e4435be7a33db08415ac1ad46e956199
Reviewed-on: https://chromium-review.googlesource.com/c/1273238Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56552}

54855b67

26 Sep, 2018 1 commit

[cleanup] Move some helper methods from Heap to ReadOnlyRoots · e5648b2a

Igor Sheludko authored 6 years ago

In particular: MapForFixedTypedArray() and EmptyFixedTypedArrayForMap().

And make ReadOnlyRoots object independent of the Heap.

Bug: v8:8015
Change-Id: Ifd17294661fac21c8e7545145280c8a2dedfe8c3
Reviewed-on: https://chromium-review.googlesource.com/1243131Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56234}

e5648b2a