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  1. 17 Dec, 2020 1 commit
  3. 16 Dec, 2020 1 commit
  5. 15 Dec, 2020 1 commit
  7. 03 Dec, 2020 1 commit
    • Dominik Inführ's avatar
      Reland "[heap] Remove SWEEPING phase in incremental marking" · dec7565f
      Dominik Inführ authored 
      This is a reland of 2afb00c0

Original change's description:
> [heap] Remove SWEEPING phase in incremental marking
>
> The SWEEPING phase in incremental marking was used to finish sweeping
> of the last GC cycle concurrently before starting incremental marking.
> This avoids potentially long pauses when starting incremental marking.
> However this shouldn't be necessary in most cases where sweeping is
> already finished when starting the next cycle. The implementation also
> didn't cleanly separate the GC cycles.
>
> In case the sweeping phase is necessary for pause times, we can
> introduce a "CompleteSweep" phase which runs right before starting
> incremental marking.
>
> Change-Id: Iaff8c06d5691e584894f57941f181d0424051eec
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567707
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71555}

Change-Id: I173bdeaf342d4c0590453f7d9eeb8ab5cfddc73c
Bug: v8:11220, v8:11221
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2571111
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71592}
      dec7565f
  9. 02 Dec, 2020 3 commits
    • Santiago Aboy Solanes's avatar
      [objects] Remove MakeExternal case for uncached internal strings · 3a6f75ac
      Santiago Aboy Solanes authored 
      Concurrently accessing internal external uncached strings is not
thread-safe. We are removing a case where we can make such a string
through MakeExternal.

Bug: v8:7790
Change-Id: I958062c15cf40ccc330600bb572de98620866e54
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2565511
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71573}
      3a6f75ac
    • Dominik Inführ's avatar
      Revert "[heap] Remove SWEEPING phase in incremental marking" · 0f8fe4e5
      Dominik Inführ authored 
      This reverts commit 2afb00c0.

Reason for revert: Some tests started to timeout.

Original change's description:
> [heap] Remove SWEEPING phase in incremental marking
>
> The SWEEPING phase in incremental marking was used to finish sweeping
> of the last GC cycle concurrently before starting incremental marking.
> This avoids potentially long pauses when starting incremental marking.
> However this shouldn't be necessary in most cases where sweeping is
> already finished when starting the next cycle. The implementation also
> didn't cleanly separate the GC cycles.
>
> In case the sweeping phase is necessary for pause times, we can
> introduce a "CompleteSweep" phase which runs right before starting
> incremental marking.
>
> Change-Id: Iaff8c06d5691e584894f57941f181d0424051eec
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567707
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71555}

TBR=ulan@chromium.org,dinfuehr@chromium.org

Change-Id: I9adea60c21ff7cdfa7bbac3e6a4a240640fa5ea9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2569766Reviewed-by: 's avatarDominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71570}
      0f8fe4e5
    • Dominik Inführ's avatar
      [heap] Remove SWEEPING phase in incremental marking · 2afb00c0
      Dominik Inführ authored 
      The SWEEPING phase in incremental marking was used to finish sweeping
of the last GC cycle concurrently before starting incremental marking.
This avoids potentially long pauses when starting incremental marking.
However this shouldn't be necessary in most cases where sweeping is
already finished when starting the next cycle. The implementation also
didn't cleanly separate the GC cycles.

In case the sweeping phase is necessary for pause times, we can
introduce a "CompleteSweep" phase which runs right before starting
incremental marking.

Change-Id: Iaff8c06d5691e584894f57941f181d0424051eec
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567707
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71555}
      2afb00c0
  11. 27 Nov, 2020 1 commit
  13. 26 Nov, 2020 1 commit
  15. 24 Nov, 2020 1 commit
  17. 20 Nov, 2020 1 commit
  19. 19 Nov, 2020 1 commit
    • Dominik Inführ's avatar
      Reland "[heap] Introduce LocalIsolate for main thread" · dc45361e
      Dominik Inführ authored 
      This is a reland of e95e1b62

After landing https://crrev.com/c/2546682, this CL can be relanded
without changes.

Original change's description:
> [heap] Introduce LocalIsolate for main thread
>
> Add a LocalIsolate for the main thread to Isolate. This LocalIsolate is
> kept alive during the whole lifetime of the Isolate. The main thread
> LocalIsolate starts in the Running state in contrast to the background
> thread LocalIsolates (those start in Parked).
>
> Code paths in Turbofan that used to create a LocalIsolate on the main
> thread can now simply use the main thread LocalIsolate.
>
> LocalIsolate for the main thread will help in reducing differences
> between the main and background threads. The goal is that the main
> thread behaves more like a background thread.
>
> The main thread LocalIsolate should also make it simpler to share code
> between main thread and background threads by using LocalIsolate for
> both.
>
> Bug: v8:10315
> Change-Id: I7fd61d305a6fd7079e2319d75c291c1021e70018
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509593
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71226}

Bug: v8:10315
Change-Id: I418b1217aeac4f3c44a0aa514dea9864f8a58656
TBR: szuend@chromium.org, yangguo@chromium.org, ulan@chromium.org, leszeks@chromium.org, neis@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2543399Reviewed-by: 's avatarDominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71274}
      dc45361e
  21. 18 Nov, 2020 1 commit
  23. 17 Nov, 2020 2 commits
    • Michael Achenbach's avatar
      Revert "[heap] Introduce LocalIsolate for main thread" · 9235f258
      Michael Achenbach authored 
      This reverts commit e95e1b62.

Reason for revert:
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm%20-%20sim%20-%20debug/23064

Original change's description:
> [heap] Introduce LocalIsolate for main thread
>
> Add a LocalIsolate for the main thread to Isolate. This LocalIsolate is
> kept alive during the whole lifetime of the Isolate. The main thread
> LocalIsolate starts in the Running state in contrast to the background
> thread LocalIsolates (those start in Parked).
>
> Code paths in Turbofan that used to create a LocalIsolate on the main
> thread can now simply use the main thread LocalIsolate.
>
> LocalIsolate for the main thread will help in reducing differences
> between the main and background threads. The goal is that the main
> thread behaves more like a background thread.
>
> The main thread LocalIsolate should also make it simpler to share code
> between main thread and background threads by using LocalIsolate for
> both.
>
> Bug: v8:10315
> Change-Id: I7fd61d305a6fd7079e2319d75c291c1021e70018
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509593
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71226}

TBR=ulan@chromium.org,yangguo@chromium.org,neis@chromium.org,leszeks@chromium.org,szuend@chromium.org,dinfuehr@chromium.org

Change-Id: Ia70b4bfe3b8fa26bf8d6a7dc612a310b0ed54073
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10315
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2543937Reviewed-by: 's avatarMichael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71228}
      9235f258
    • Dominik Inführ's avatar
      [heap] Introduce LocalIsolate for main thread · e95e1b62
      Dominik Inführ authored 
      Add a LocalIsolate for the main thread to Isolate. This LocalIsolate is
kept alive during the whole lifetime of the Isolate. The main thread
LocalIsolate starts in the Running state in contrast to the background
thread LocalIsolates (those start in Parked).

Code paths in Turbofan that used to create a LocalIsolate on the main
thread can now simply use the main thread LocalIsolate.

LocalIsolate for the main thread will help in reducing differences
between the main and background threads. The goal is that the main
thread behaves more like a background thread.

The main thread LocalIsolate should also make it simpler to share code
between main thread and background threads by using LocalIsolate for
both.

Bug: v8:10315
Change-Id: I7fd61d305a6fd7079e2319d75c291c1021e70018
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509593Reviewed-by: 's avatarSimon Zünd <szuend@chromium.org>
Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71226}
      e95e1b62
  25. 16 Nov, 2020 1 commit
  27. 11 Nov, 2020 4 commits
  29. 10 Nov, 2020 1 commit
  31. 09 Nov, 2020 1 commit
  33. 03 Nov, 2020 1 commit
  35. 30 Oct, 2020 1 commit
    • Michael Lippautz's avatar
      global-handles: Fix ASAN fake stack handling · aad7b7ff
      Michael Lippautz authored 
      We previously assumed that a fake stack should be mapped back to a
real stack based on fake-stack offsets. This is not correct: Fake and
real stack are disjoint and both contain the corresponding slot
values.

For global handles this means that on-stack handles must be registered
using their real stack frame base to be able to purge them
occasionally based on the current stack address.

When dealing with a slot though, the GC can just dereference the slot
for a value, indeppendent of whether the slot is in a fake or real
frame.

Drive-by: Fix tests that do not want stack handles by creating
handles on heap.

Change-Id: I2c86c8e047bd0d48c24c2642b2b4dba284a93909
Bug: chromium:1139914
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2507720
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70897}
      aad7b7ff
  37. 29 Oct, 2020 1 commit
  39. 28 Oct, 2020 1 commit
  41. 27 Oct, 2020 1 commit
  43. 23 Oct, 2020 2 commits
  45. 21 Oct, 2020 1 commit
    • Jakob Gruber's avatar
      Reland "Reland "[deoptimizer] Change deopt entries into builtins"" · c7cb9bec
      Jakob Gruber authored 
      This is a reland of fbfa9bf4

The arm64 was missing proper codegen for CFI, thus sizes were off.

Original change's description:
> Reland "[deoptimizer] Change deopt entries into builtins"
>
> This is a reland of 7f58ced7
>
> It fixes the different exit size emitted on x64/Atom CPUs due to
> performance tuning in TurboAssembler::Call. Additionally, add
> cctests to verify the fixed size exits.
>
> Original change's description:
> > [deoptimizer] Change deopt entries into builtins
> >
> > While the overall goal of this commit is to change deoptimization
> > entries into builtins, there are multiple related things happening:
> >
> > - Deoptimization entries, formerly stubs (i.e. Code objects generated
> >   at runtime, guaranteed to be immovable), have been converted into
> >   builtins. The major restriction is that we now need to preserve the
> >   kRootRegister, which was formerly used on most architectures to pass
> >   the deoptimization id. The solution differs based on platform.
> > - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> > - Removed heap/ support for immovable Code generation.
> > - Removed the DeserializerData class (no longer needed).
> > - arm64: to preserve 4-byte deopt exits, introduced a new optimization
> >   in which the final jump to the deoptimization entry is generated
> >   once per Code object, and deopt exits can continue to emit a
> >   near-call.
> > - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
> >   sizes by 4/8, 5, and 5 bytes, respectively.
> >
> > On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> > by using the same strategy as on arm64 (recalc deopt id from return
> > address). Before:
> >
> >  e300a002       movw r10, <id>
> >  e59fc024       ldr ip, [pc, <entry offset>]
> >  e12fff3c       blx ip
> >
> > After:
> >
> >  e59acb35       ldr ip, [r10, <entry offset>]
> >  e12fff3c       blx ip
> >
> > On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> > with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> > object (max 32 bytes added overhead per Code object). Before:
> >
> >  9401cdae       bl <entry offset>
> >
> > After:
> >
> >  # eager deoptimization entry jump.
> >  f95b1f50       ldr x16, [x26, <eager entry offset>]
> >  d61f0200       br x16
> >  # lazy deoptimization entry jump.
> >  f95b2b50       ldr x16, [x26, <lazy entry offset>]
> >  d61f0200       br x16
> >  # the deopt exit.
> >  97fffffc       bl <eager deoptimization entry jump offset>
> >
> > On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
> >
> >  bb00000000     mov ebx,<id>
> >  e825f5372b     call <entry>
> >
> > After:
> >
> >  e8ea2256ba     call <entry>
> >
> > On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
> >
> >  49c7c511000000 REX.W movq r13,<id>
> >  e8ea2f0700     call <entry>
> >
> > After:
> >
> >  41ff9560360000 call [r13+<entry offset>]
> >
> > Bug: v8:8661,v8:8768
> > Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> > Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> > Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#70597}
>
> Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
> Bug: v8:8661,v8:8768,chromium:1140165
> Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70655}

Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
Bug: v8:8661
Bug: v8:8768
Bug: chromium:1140165
Change-Id: I471cc94fc085e527dc9bfb5a84b96bd907c2333f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2488682Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70672}
      c7cb9bec
  47. 20 Oct, 2020 3 commits
    • Maya Lekova's avatar
      Revert "Reland "[deoptimizer] Change deopt entries into builtins"" · 7c7aa4fa
      Maya Lekova authored 
      This reverts commit fbfa9bf4.

Reason for revert: Seems to break arm64 sim CFI build (please see DeoptExitSizeIfFixed) - https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20CFI/2808

Original change's description:
> Reland "[deoptimizer] Change deopt entries into builtins"
>
> This is a reland of 7f58ced7
>
> It fixes the different exit size emitted on x64/Atom CPUs due to
> performance tuning in TurboAssembler::Call. Additionally, add
> cctests to verify the fixed size exits.
>
> Original change's description:
> > [deoptimizer] Change deopt entries into builtins
> >
> > While the overall goal of this commit is to change deoptimization
> > entries into builtins, there are multiple related things happening:
> >
> > - Deoptimization entries, formerly stubs (i.e. Code objects generated
> >   at runtime, guaranteed to be immovable), have been converted into
> >   builtins. The major restriction is that we now need to preserve the
> >   kRootRegister, which was formerly used on most architectures to pass
> >   the deoptimization id. The solution differs based on platform.
> > - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> > - Removed heap/ support for immovable Code generation.
> > - Removed the DeserializerData class (no longer needed).
> > - arm64: to preserve 4-byte deopt exits, introduced a new optimization
> >   in which the final jump to the deoptimization entry is generated
> >   once per Code object, and deopt exits can continue to emit a
> >   near-call.
> > - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
> >   sizes by 4/8, 5, and 5 bytes, respectively.
> >
> > On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> > by using the same strategy as on arm64 (recalc deopt id from return
> > address). Before:
> >
> >  e300a002       movw r10, <id>
> >  e59fc024       ldr ip, [pc, <entry offset>]
> >  e12fff3c       blx ip
> >
> > After:
> >
> >  e59acb35       ldr ip, [r10, <entry offset>]
> >  e12fff3c       blx ip
> >
> > On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> > with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> > object (max 32 bytes added overhead per Code object). Before:
> >
> >  9401cdae       bl <entry offset>
> >
> > After:
> >
> >  # eager deoptimization entry jump.
> >  f95b1f50       ldr x16, [x26, <eager entry offset>]
> >  d61f0200       br x16
> >  # lazy deoptimization entry jump.
> >  f95b2b50       ldr x16, [x26, <lazy entry offset>]
> >  d61f0200       br x16
> >  # the deopt exit.
> >  97fffffc       bl <eager deoptimization entry jump offset>
> >
> > On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
> >
> >  bb00000000     mov ebx,<id>
> >  e825f5372b     call <entry>
> >
> > After:
> >
> >  e8ea2256ba     call <entry>
> >
> > On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
> >
> >  49c7c511000000 REX.W movq r13,<id>
> >  e8ea2f0700     call <entry>
> >
> > After:
> >
> >  41ff9560360000 call [r13+<entry offset>]
> >
> > Bug: v8:8661,v8:8768
> > Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> > Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> > Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#70597}
>
> Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
> Bug: v8:8661,v8:8768,chromium:1140165
> Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70655}

TBR=ulan@chromium.org,rmcilroy@chromium.org,jgruber@chromium.org,tebbi@chromium.org

Change-Id: I4739a3475bfd8ee0cfbe4b9a20382f91a6ef1bf0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8661
Bug: v8:8768
Bug: chromium:1140165
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485223Reviewed-by: 's avatarMaya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70658}
      7c7aa4fa
    • Jakob Gruber's avatar
      Reland "[deoptimizer] Change deopt entries into builtins" · fbfa9bf4
      Jakob Gruber authored 
      This is a reland of 7f58ced7

It fixes the different exit size emitted on x64/Atom CPUs due to
performance tuning in TurboAssembler::Call. Additionally, add
cctests to verify the fixed size exits.

Original change's description:
> [deoptimizer] Change deopt entries into builtins
>
> While the overall goal of this commit is to change deoptimization
> entries into builtins, there are multiple related things happening:
>
> - Deoptimization entries, formerly stubs (i.e. Code objects generated
>   at runtime, guaranteed to be immovable), have been converted into
>   builtins. The major restriction is that we now need to preserve the
>   kRootRegister, which was formerly used on most architectures to pass
>   the deoptimization id. The solution differs based on platform.
> - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> - Removed heap/ support for immovable Code generation.
> - Removed the DeserializerData class (no longer needed).
> - arm64: to preserve 4-byte deopt exits, introduced a new optimization
>   in which the final jump to the deoptimization entry is generated
>   once per Code object, and deopt exits can continue to emit a
>   near-call.
> - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
>   sizes by 4/8, 5, and 5 bytes, respectively.
>
> On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> by using the same strategy as on arm64 (recalc deopt id from return
> address). Before:
>
>  e300a002       movw r10, <id>
>  e59fc024       ldr ip, [pc, <entry offset>]
>  e12fff3c       blx ip
>
> After:
>
>  e59acb35       ldr ip, [r10, <entry offset>]
>  e12fff3c       blx ip
>
> On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> object (max 32 bytes added overhead per Code object). Before:
>
>  9401cdae       bl <entry offset>
>
> After:
>
>  # eager deoptimization entry jump.
>  f95b1f50       ldr x16, [x26, <eager entry offset>]
>  d61f0200       br x16
>  # lazy deoptimization entry jump.
>  f95b2b50       ldr x16, [x26, <lazy entry offset>]
>  d61f0200       br x16
>  # the deopt exit.
>  97fffffc       bl <eager deoptimization entry jump offset>
>
> On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
>
>  bb00000000     mov ebx,<id>
>  e825f5372b     call <entry>
>
> After:
>
>  e8ea2256ba     call <entry>
>
> On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
>
>  49c7c511000000 REX.W movq r13,<id>
>  e8ea2f0700     call <entry>
>
> After:
>
>  41ff9560360000 call [r13+<entry offset>]
>
> Bug: v8:8661,v8:8768
> Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70597}

Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
Bug: v8:8661,v8:8768,chromium:1140165
Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70655}
      fbfa9bf4
    • Jakob Gruber's avatar
      Revert "[deoptimizer] Change deopt entries into builtins" · 8bc9a794
      Jakob Gruber authored 
      This reverts commit 7f58ced7.

Reason for revert: Segfaults on Atom_x64 https://ci.chromium.org/p/v8-internal/builders/ci/v8_linux64_atom_perf/5686?

Original change's description:
> [deoptimizer] Change deopt entries into builtins
>
> While the overall goal of this commit is to change deoptimization
> entries into builtins, there are multiple related things happening:
>
> - Deoptimization entries, formerly stubs (i.e. Code objects generated
>   at runtime, guaranteed to be immovable), have been converted into
>   builtins. The major restriction is that we now need to preserve the
>   kRootRegister, which was formerly used on most architectures to pass
>   the deoptimization id. The solution differs based on platform.
> - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> - Removed heap/ support for immovable Code generation.
> - Removed the DeserializerData class (no longer needed).
> - arm64: to preserve 4-byte deopt exits, introduced a new optimization
>   in which the final jump to the deoptimization entry is generated
>   once per Code object, and deopt exits can continue to emit a
>   near-call.
> - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
>   sizes by 4/8, 5, and 5 bytes, respectively.
>
> On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> by using the same strategy as on arm64 (recalc deopt id from return
> address). Before:
>
>  e300a002       movw r10, <id>
>  e59fc024       ldr ip, [pc, <entry offset>]
>  e12fff3c       blx ip
>
> After:
>
>  e59acb35       ldr ip, [r10, <entry offset>]
>  e12fff3c       blx ip
>
> On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> object (max 32 bytes added overhead per Code object). Before:
>
>  9401cdae       bl <entry offset>
>
> After:
>
>  # eager deoptimization entry jump.
>  f95b1f50       ldr x16, [x26, <eager entry offset>]
>  d61f0200       br x16
>  # lazy deoptimization entry jump.
>  f95b2b50       ldr x16, [x26, <lazy entry offset>]
>  d61f0200       br x16
>  # the deopt exit.
>  97fffffc       bl <eager deoptimization entry jump offset>
>
> On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
>
>  bb00000000     mov ebx,<id>
>  e825f5372b     call <entry>
>
> After:
>
>  e8ea2256ba     call <entry>
>
> On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
>
>  49c7c511000000 REX.W movq r13,<id>
>  e8ea2f0700     call <entry>
>
> After:
>
>  41ff9560360000 call [r13+<entry offset>]
>
> Bug: v8:8661,v8:8768
> Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70597}

TBR=ulan@chromium.org,rmcilroy@chromium.org,jgruber@chromium.org,tebbi@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:8661,v8:8768,chromium:1140165
Change-Id: I3df02ab42f6e02233d9f6fb80e8bb18f76870d91
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485504Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70649}
      8bc9a794
  49. 19 Oct, 2020 1 commit
    • Jakob Gruber's avatar
      [deoptimizer] Change deopt entries into builtins · 7f58ced7
      Jakob Gruber authored 
      While the overall goal of this commit is to change deoptimization
entries into builtins, there are multiple related things happening:

- Deoptimization entries, formerly stubs (i.e. Code objects generated
  at runtime, guaranteed to be immovable), have been converted into
  builtins. The major restriction is that we now need to preserve the
  kRootRegister, which was formerly used on most architectures to pass
  the deoptimization id. The solution differs based on platform.
- Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
- Removed heap/ support for immovable Code generation.
- Removed the DeserializerData class (no longer needed).
- arm64: to preserve 4-byte deopt exits, introduced a new optimization
  in which the final jump to the deoptimization entry is generated
  once per Code object, and deopt exits can continue to emit a
  near-call.
- arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
  sizes by 4/8, 5, and 5 bytes, respectively.

On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
by using the same strategy as on arm64 (recalc deopt id from return
address). Before:

 e300a002       movw r10, <id>
 e59fc024       ldr ip, [pc, <entry offset>]
 e12fff3c       blx ip

After:

 e59acb35       ldr ip, [r10, <entry offset>]
 e12fff3c       blx ip

On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
with CFI). Additionally, up to 4 builtin jumps are emitted per Code
object (max 32 bytes added overhead per Code object). Before:

 9401cdae       bl <entry offset>

After:

 # eager deoptimization entry jump.
 f95b1f50       ldr x16, [x26, <eager entry offset>]
 d61f0200       br x16
 # lazy deoptimization entry jump.
 f95b2b50       ldr x16, [x26, <lazy entry offset>]
 d61f0200       br x16
 # the deopt exit.
 97fffffc       bl <eager deoptimization entry jump offset>

On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:

 bb00000000     mov ebx,<id>
 e825f5372b     call <entry>

After:

 e8ea2256ba     call <entry>

On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:

 49c7c511000000 REX.W movq r13,<id>
 e8ea2f0700     call <entry>

After:

 41ff9560360000 call [r13+<entry offset>]

Bug: v8:8661,v8:8768
Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70597}
      7f58ced7
  51. 17 Oct, 2020 1 commit
  53. 16 Oct, 2020 2 commits
    • Pierre Langlois's avatar
      [heap] Make maximum regular code object size a runtime value. · f4376ec8
      Pierre Langlois authored 
      Executable V8 pages include 3 reserved OS pages: one for the writable
header and two as guards. On systems with 64k OS pages, the amount of
allocatable space left for objects can then be quite smaller than the
page size, only 64k for each 256k page.

This means regular code objects cannot be larger than 64k, while the
maximum regular object size is fixed to 128k, half of the page size. As
a result code object never reach this limit and we can end up filling
regular pages with few large code objects.

To fix this, we change the maximum code object size to be runtime value,
set to half of the allocatable space per page. On systems with 64k OS
pages, the limit will be 32k.

Alternatively, we could increase the V8 page size to 512k on Arm64 linux
so we wouldn't waste code space. However, systems with 4k OS pages are
more common, and those with 64k pages tend to have more memory available
so we should be able to live with it.

Bug: v8:10808
Change-Id: I5d807e7a3df89f1e9c648899e9ba2f8e2648264c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460809Reviewed-by: 's avatarIgor Sheludko <ishell@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#70569}
      f4376ec8
    • Dominik Inführ's avatar
      Reland "[compiler, heap] Create LocalHeap outside of ExecuteJob" · de914c75
      Dominik Inführ authored 
      This is a reland of 44708a5b

Original change's description:
> [compiler, heap] Create LocalHeap outside of ExecuteJob
>
> Create LocalHeap directly in the Task or in GetOptimizedCodeNow and
> pass its reference as argument to ExecuteJob. This allows us to create
> LocalHeap differently for the main and background thread, e.g. by
> passing an additional argument to the constructor in the future.
> It will be required in the future anyways when the main thread will
> have its own LocalHeap/LocalIsolate.
>
> Extending the scope of LocalHeap, also made
> HandleBase::IsDereferenceAllowed more precise and uncovered two
> potential issues: heap accesses in
> OptimizingCompileDispatcher::CompileNext and PipelineImpl::AssembleCode
> with --code-comments.
>
> LocalHeap can now be created in the parked state. Also fixed a data
> race with LocalHeap's destructor publishing write barrier entries
> without holding the lock.
>
> Bug: v8:10315
> Change-Id: I9226972601a07b87108cd66efbbb6a0d118af58d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460818
> Commit-Queue: Georg Neis <neis@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70521}

Bug: v8:10315
Change-Id: I4c459fd6dfb98d47fc9941c0dc6864bf5a1d2d3e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2474788Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Reviewed-by: 's avatarSantiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70560}
      de914c75
  55. 15 Oct, 2020 2 commits
    • Georg Neis's avatar
      Revert "[compiler, heap] Create LocalHeap outside of ExecuteJob" · 04c85d7c
      Georg Neis authored 
      This reverts commit 44708a5b.

Reason for revert: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20TSAN/33692

Original change's description:
> [compiler, heap] Create LocalHeap outside of ExecuteJob
>
> Create LocalHeap directly in the Task or in GetOptimizedCodeNow and
> pass its reference as argument to ExecuteJob. This allows us to create
> LocalHeap differently for the main and background thread, e.g. by
> passing an additional argument to the constructor in the future.
> It will be required in the future anyways when the main thread will
> have its own LocalHeap/LocalIsolate.
>
> Extending the scope of LocalHeap, also made
> HandleBase::IsDereferenceAllowed more precise and uncovered two
> potential issues: heap accesses in
> OptimizingCompileDispatcher::CompileNext and PipelineImpl::AssembleCode
> with --code-comments.
>
> LocalHeap can now be created in the parked state. Also fixed a data
> race with LocalHeap's destructor publishing write barrier entries
> without holding the lock.
>
> Bug: v8:10315
> Change-Id: I9226972601a07b87108cd66efbbb6a0d118af58d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460818
> Commit-Queue: Georg Neis <neis@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70521}

TBR=ulan@chromium.org,neis@chromium.org,leszeks@chromium.org,solanes@chromium.org,dinfuehr@chromium.org

Change-Id: I9dd1f8ca6237d5716b6d8938cef0ee3f642f3166
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10315
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2474118Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70522}
      04c85d7c
    • Dominik Inführ's avatar
      [compiler, heap] Create LocalHeap outside of ExecuteJob · 44708a5b
      Dominik Inführ authored 
      Create LocalHeap directly in the Task or in GetOptimizedCodeNow and
pass its reference as argument to ExecuteJob. This allows us to create
LocalHeap differently for the main and background thread, e.g. by
passing an additional argument to the constructor in the future.
It will be required in the future anyways when the main thread will
have its own LocalHeap/LocalIsolate.

Extending the scope of LocalHeap, also made
HandleBase::IsDereferenceAllowed more precise and uncovered two
potential issues: heap accesses in
OptimizingCompileDispatcher::CompileNext and PipelineImpl::AssembleCode
with --code-comments.

LocalHeap can now be created in the parked state. Also fixed a data
race with LocalHeap's destructor publishing write barrier entries
without holding the lock.

Bug: v8:10315
Change-Id: I9226972601a07b87108cd66efbbb6a0d118af58d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460818
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
Reviewed-by: 's avatarSantiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70521}
      44708a5b
  57. 14 Oct, 2020 1 commit