A sample can be taken when Thread::Current() and Thread::Current()->isolate() are non-NULL. When a thread is entering or exiting an isolate, the is a brief window between the TLS being set/cleared and Isolate::mutator_thread_ being set/cleared.
TEST=vm/cc/Profiler_EnterExitIsolate
Bug: https://github.com/flutter/flutter/issues/134548
Change-Id: I7a6b25dabf930e8480d1a85d7f24c4765fc36b15
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/328380
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
We were exporting all symbols to the dynamic table so that they could be looked up using `dladdr` for the profiler and backtracer. The symbols include our statically-linked libcxx, which can create trouble when another DSO has a different version of libcxx. Now we export only the VM embedding API functions (`Dart_*`) and use a specially produced table to do the symbolization.
TEST=runtime/tests/vm/dart/exported_symbols_test.dart
TEST=runtime/tests/vm/dart/symbolized_crash_test.dart
Bug: https://github.com/dart-lang/sdk/issues/53267
Change-Id: I2ee494fba86f67127ba0f6f402622f01a4662207
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/323702
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Some cleanups factored out of a larger CL (which refactors enter/exit of threads):
* remove unused `#include "vm/thread_registry.h"`
* remove unused/unnecessary fields from [Thread] object
* rename IsMutator() -> IsDartMutator()
* make tests using setjmp() drain the sticky error
=> to ensure there's no sticky error on isolate shutdown
TEST=ci
Change-Id: I53935e8bd0628ab3768627d6d5e01c3f0e3a57ad
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296582
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
For every isolate there should be only one mutator with
a unique [Thread] object.
We change existing tests that use this functionality to instead use
`Thread::{Enter,Exit}IsolateGroupAsHelper`. It also results in a net
removal of code.
TEST=ci
Change-Id: Ic326e868a98ddedbab5b8c429252d38ea71bbf04
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/295940
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
This reverts commit c67fac9cb4.
Reason for revert: Regresses `dart:io` performance and causes
failures.
https://github.com/dart-lang/sdk/issues/51639
Original change's description:
> [vm] Remove tcmalloc and malloc profiler.
>
> The standalone VM originally began statically linking tcmalloc to work around bugs in the system malloc for Fiber. Later it used tcmalloc's hooks to implement a profiler, but this is rarely used since it is only available in debug mode, misses early allocations, and often misses late allocations from an exhausted sample buffer. Removing it altogether avoids build complexity around which combinations of compiler/architecture/sysroot support tcmalloc, and reduces binary size.
>
> TEST=ci
> Change-Id: I4b259e18b82b2d12a2a60962aabf83bd8d997d19
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/286120
> Reviewed-by: Ben Konyi <bkonyi@google.com>
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
Change-Id: I4395edd6f5bd7e26b4e38f4d931ad2ea67afba18
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/286925
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
The standalone VM originally began statically linking tcmalloc to work around bugs in the system malloc for Fiber. Later it used tcmalloc's hooks to implement a profiler, but this is rarely used since it is only available in debug mode, misses early allocations, and often misses late allocations from an exhausted sample buffer. Removing it altogether avoids build complexity around which combinations of compiler/architecture/sysroot support tcmalloc, and reduces binary size.
TEST=ci
Change-Id: I4b259e18b82b2d12a2a60962aabf83bd8d997d19
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/286120
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
The PC marker slots are transiently invalid during a compaction, but the profiler's stack walker no longer uses them, as they are completely absent in bare instructions mode.
TEST=ci
Change-Id: I3dba373ccccaba48e6dcc2b01d48e5e75620a4db
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/284744
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
* Don't compile it with omit frame pointer even in PRODUCT.
* Dump the first frame even if we give up on unwinding.
* Dump compiler state even if we give up on unwinding.
* Don't abort stack dump if PC for the outermost frame is 0 (can happen
when calling pure virtual method for example).
TEST=manually tested by making compiler crash during code generation
Change-Id: Iddeafbdad8e8588f19197d5dd49af14b8fc63134
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/278341
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Examples of the new line added to non-symbolic stack traces:
os: linux arch: x64 comp: yes sim: no
(Running on linux-x64c)
os: macos arch: arm64 comp: no sim: yes
(Running on mac-simarm64)
This CL also abstracts out the separate hardcoded strings across
the codebase for host and target OS and architecture into
definitions in platform/globals.h to ensure that they stay
in sync across different uses.
TEST=vm/dart{,_2}/use_dwarf_stack_traces_flag
Issue: https://github.com/flutter/flutter/pull/101586
Change-Id: Ifdfea5138dd1003f561da0174e89aebc165bf9b0
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-mac-product-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-simarm_x64-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-ffi-android-release-arm-try,vm-ffi-android-release-arm64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/253283
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Building an empty CPU profile is still costly as function tables are
populated whether or not there's samples in the profile. This change
checks to see if any sample in the list of SampleBlocks was collected
under a UserTag with streaming enabled before building the profile.
TEST=CQ, manual testing
Change-Id: Ib526f9999a8b2bf48a7df1488c7dcf959031cf5b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/238183
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
* Use CompilerPass::GenerateCode in AOT to ensure we print
the graph if the code generation crashes.
* Enable Dart_DumpNativeStackTrace in gen_snapshot even in
PRODUCT builds.
Additionally enable disassembler in gen_snapshot even in
PRODUCT builds.
TEST=tested manually
Change-Id: I951d62ca07c7882fa1d8e765d4b5ffd26edd9456
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/233880
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Auto-Submit: Slava Egorov <vegorov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
On architectures with a link register, don't generate a profiler marker into what a foreign stack walker will interpret as the caller's frame area. If the caller is unwound based on SP instead of FP, this will cause it incorrectly identify its own caller.
TEST=ci (--profile_vm=false)
Bug: b/220804295
Change-Id: I3cc9d579f9c95476e23040c84574d2965b5eb7ac
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/235164
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Implements a backend targeting RV32GC and RV64GC, based on Linux standardizing around GC. The assembler is written to make it easy to disable usage of C, but because the sizes of some instruction sequences are compile-time constants, an additional build configuration would need to be defined to make use of it.
The assembler and disassembler cover every RV32/64GC instruction. The simulator covers all instructions except accessing CSRs and the floating point state accessible through such, include accrued exceptions and dynamic rounding mode.
Quirks:
- RISC-V is a compare-and-branch architecture, but some existing "architecture-independent" parts of the Dart compiler assume a condition code architecture. To avoid rewriting these parts, we use a peephole in the assembler to map to compare-and-branch. See Assembler::BranchIf. Luckily nothing depended on taking multiple branches on the same condition code set.
- There are no hardware overflow checks, so we must use Hacker's Delight style software checks. Often these are very cheap: if the sign of one operand is known, a single branch is needed.
- The ranges of RISC-V branches and jumps are such that we use 3 levels of generation for forward branches, instead of the 2 levels of near and far branches used on ARM[64]. Nearly all code is handled by the first two levels with 20-bits of range, with enormous regex matchers triggering the third level that uses aupic+jalr to get 32-bits of range.
- For PC-relative calls in AOT, we always generate auipc+jalr pairs with 32-bits of range, so we never generate trampolines.
- Only a subset of registers are available in some compressed instructions, so we assign the most popular uses to these registers. In particular, THR, TMP[2], CODE and PP. This has the effect of assigning CODE and PP to volatile registers in the C calling convention, whereas they are assigned preserved registers on the other architectures. As on ARM64, PP is untagged; this is so short indices can be accessed with a compressed instruction.
- There are no push or pop instructions, so combining pushes and pops is preferred so we can update SP once.
- The C calling convention has a strongly aligned stack, but unlike on ARM64 we don't need to use an alternate stack pointer. The author ensured language was added to the RISC-V psABI making the OS responsible for realigning the stack pointer for signal handlers, allowing Dart to leave the stack pointer misaligned from the C calling convention's point of view until a foreign call.
- We don't bother with the link register tracking done on ARM[64]. Instead we make use of an alternate link register to avoid inline spilling in the write barrier.
Unimplemented:
- non-trivial FFI cases
- Compressed pointers - No intention to implement.
- Unboxed SIMD - We might make use of the V extension registers when the V extension is ratified.
- BigInt intrinsics
TEST=existing tests for IL level, new tests for assembler/disassembler/simulator
Bug: https://github.com/dart-lang/sdk/issues/38587
Bug: https://github.com/dart-lang/sdk/issues/48164
Change-Id: I991d1df4be5bf55efec5371b767b332d37dfa3e0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/217289
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
profiler events.
`Event.cpuSamples` is now a `CpuSamplesEvent` rather than a `CpuSamples`
object, where `CpuSamplesEvent` returns `(@Object|NativeFunction)[]` rather
than `(@Func|NativeFunction)[]`, resulting in a smaller JSON payload.
TEST=get_object_rpc_test.dart,get_cached_cpu_samples_test.dart
Change-Id: I1ad5e3df8840b8c41735d10c6c8669f6503e54a8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/219284
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
This changes Profiler::DumpStackTrace to include information available
in the CompilerState attached to the thread into the crash report.
This includes the name of the function being compiled, compilation mode,
current phase, flow graph, instruction being compiled.
TEST=manually by causing compiler to crash
Change-Id: I310629f032a86781e30f0a5e218d21df7d27528e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/220001
Auto-Submit: Slava Egorov <vegorov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Don't allocate zones, timeline events or profile samples in the compressible region, since these allocations don't yeild compressed pointers and are competing for a limited resource.
TEST=ci
Bug: b/196510517
Change-Id: I4fc2f0d67060f927fa10d241b15b1cae3b73d919
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212400
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
This reverts commit 1796160606.
Reason for revert: Still seeing failures.
Original change's description:
> Reland "[ package:dds ] Add support for caching CPU samples based on UserTag"
>
> This reverts commit 4160747ef6.
>
> It seems like 9397b8ff05 should have fixed the original failures we were seeing and the failing bots in question seem to be passing when running try jobs.
>
> TBR=asiva@ (discussed offline)
>
> TEST=Existing service tests + get_cached_cpu_samples_test
> Change-Id: I1c50c0e79375df819a0bd68e68ac28c3064874c8
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208441
> Reviewed-by: Ben Konyi <bkonyi@google.com>
> Commit-Queue: Ben Konyi <bkonyi@google.com>
TBR=bkonyi@google.com,asiva@google.com
Change-Id: Ic522ab61b430673533c94ecd0c91bee569a0add6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208960
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
This reverts commit 4160747ef6.
It seems like 9397b8ff05 should have fixed the original failures we were seeing and the failing bots in question seem to be passing when running try jobs.
TBR=asiva@ (discussed offline)
TEST=Existing service tests + get_cached_cpu_samples_test
Change-Id: I1c50c0e79375df819a0bd68e68ac28c3064874c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208441
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
Both SampleBlock::ReserveAllocationSample and
SampleBlock::ReserveCPUSample can return nullptr, so that needs to be
appropriately handled in SampleBlock::ReserveSampleAndLink. The only
caller of the latter checks for nullptr, so pass though nullptr results
from the former methods.
TEST=Fixes current service tests failures on some trybots,
see test results on CL.
Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-debug-ia32-try,app-kernel-linux-debug-x64-try
Change-Id: Ib70cc6726862bc5fe3bfb0c06ee2aae84ec026c3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208321
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Clement Skau <cskau@google.com>
DDS can be configured to listen for CPU sample events and cache samples
that were collected while certain UserTags are active. These cached
samples are stored in a ring buffer and are stored until the isolate
shuts down.
TEST=pkg/dds/test/get_cached_cpu_samples_test.dart
Change-Id: Ib20770f59f1672c703413486f87795b3bb23f676
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/207206
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Kenzie Schmoll <kenzieschmoll@google.com>
This relands https://dart-review.googlesource.com/c/sdk/+/205633
but without renaming TARGET_OS_IPHONE to DART_TARGET_OS_IPHONE.
It also changes uses of TARGET_OS_IOS to
DART_TARGET_OS_MACOS_IOS to be consistent with the rest of the
VM.
TargetConditionals.h for XCode 13 defines several
TARGET_OS_* preprocessor symbols that confuse the
Dart build. There is probably a more targeted fix
for this, but renaming the symbols that Dart uses
will also prevent this problem if more symbols
are added to the platform headers in the future.
See: https://github.com/dart-lang/sdk/issues/46499
TEST=It builds.
Change-Id: Ie775c19dd23cfdf5f65e5ebc6ee4ec3a561676fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205860
Commit-Queue: Zach Anderson <zra@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
TargetConditionals.h for XCode 13 defines several
TARGET_OS_* preprocessor symbols that confuse the
Dart build. There is probably a more targeted fix
for this, but renaming the symbols that Dart uses
will also prevent this problem if more symbols
are added to the platform headers in the future.
See: https://github.com/dart-lang/sdk/issues/46499
TEST=It builds.
Change-Id: I3b33a03b4a9a14b76d55fe12f8cdefec4b3c3664
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205633
Commit-Queue: Zach Anderson <zra@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
In practice, the Dart stack is usually much deeper than 8 frames, causing a typical tick to chain multiple Samples together. Increasing the number of frames covered by a Sample causes the typical tick to waste less memory on the non-frame portions of linked Samples.
For a run of dart2js compiling hello_world, increasing the frames-per-Sample from 8 to 32 decreases the memory required to represent all the ticks from 11930560 to 6907120 (-42%), with diminishing returns thereafter.
This CL does not make a compensating decrease the default number of Samples in the buffer, so it has the effect of increasing the time range covered by the buffer for deep stacks by ~4x while only increasing memory usage a bit less than 2x.
TEST=ci
Change-Id: I60b17263dcb900fff4198ca6039753828295bf38
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/202308
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
This is a reland of b6dc4dad4d
TEST=ci
Original change's description:
> [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
>
> The following changes are done in preparation for the removal of Code
> objects in AOT with --dwarf-stack-traces:
>
> * Stack trace objects are extended to hold uword PCs (which may not
> fit into Smi range).
>
> * Scanning stack frames in GC (StackFrame::VisitObjectPointers)
> now avoids using Code objects.
> In order to find CompressedStackMaps it now calls
> ReversePc::FindCompressedStackMaps.
>
> * Singleton Code object (StubCode::UnknownDartCode()) is prepared as
> a replacement for Code objects in stack traces. It has
> PayloadStart() == 0 and Size() == kUwordMax so it includes
> arbitrary PCs.
>
> * In --dwarf-stack-traces mode, most Code objects obtained from stack
> frames are replaced with StubCode::UnknownDartCode().
> This simulates future behavior of ReversePc::Lookup when Code objects
> will be removed.
>
> Issue: https://github.com/dart-lang/sdk/issues/44852
> Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
> TEST=ci
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
Change-Id: Ia2fc4672a085cd963b7fc103369851df3603590c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/186202
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
This reverts commit b6dc4dad4d.
Reason for revert: broke package:vm_snapshot_analysis in Flutter
(https://github.com/flutter/flutter/issues/76313).
Original change's description:
> [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
>
> The following changes are done in preparation for the removal of Code
> objects in AOT with --dwarf-stack-traces:
>
> * Stack trace objects are extended to hold uword PCs (which may not
> fit into Smi range).
>
> * Scanning stack frames in GC (StackFrame::VisitObjectPointers)
> now avoids using Code objects.
> In order to find CompressedStackMaps it now calls
> ReversePc::FindCompressedStackMaps.
>
> * Singleton Code object (StubCode::UnknownDartCode()) is prepared as
> a replacement for Code objects in stack traces. It has
> PayloadStart() == 0 and Size() == kUwordMax so it includes
> arbitrary PCs.
>
> * In --dwarf-stack-traces mode, most Code objects obtained from stack
> frames are replaced with StubCode::UnknownDartCode().
> This simulates future behavior of ReversePc::Lookup when Code objects
> will be removed.
>
> Issue: https://github.com/dart-lang/sdk/issues/44852
> Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
> TEST=ci
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I6f66171eecf1133363a7ce56193e782e43a20baf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/185488
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
The following changes are done in preparation for the removal of Code
objects in AOT with --dwarf-stack-traces:
* Stack trace objects are extended to hold uword PCs (which may not
fit into Smi range).
* Scanning stack frames in GC (StackFrame::VisitObjectPointers)
now avoids using Code objects.
In order to find CompressedStackMaps it now calls
ReversePc::FindCompressedStackMaps.
* Singleton Code object (StubCode::UnknownDartCode()) is prepared as
a replacement for Code objects in stack traces. It has
PayloadStart() == 0 and Size() == kUwordMax so it includes
arbitrary PCs.
* In --dwarf-stack-traces mode, most Code objects obtained from stack
frames are replaced with StubCode::UnknownDartCode().
This simulates future behavior of ReversePc::Lookup when Code objects
will be removed.
Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
TEST=ci
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Ryan Macnak