Currently, if d8 is run with the --turbo-profiling flag, it prints info
about every TurboFan-compiled function. This info includes the number of
times that each basic block in the function was run. It also includes
text representations of the function's schedule and code, so that the
person reading the output can associate counters with blocks of code.
The data about each function is currently stored in a
BasicBlockProfiler::Data instance, which is attached to a list owned by
the singleton BasicBlockProfiler. Each Data contains an
std::vector<uint32_t> which represents how many times each block in the
function has executed. The generated code for each block uses a raw
pointer into the storage of that vector to implement incrementing the
counter.
With this change, if you compile with v8_enable_builtins_profiling and
then run with --turbo-profiling, d8 will print that same info about
builtins too.
In order to generate code that can survive being serialized to a
snapshot and reloaded, this change uses counters in the JS heap instead
of a std::vector outside the JS heap. The steps for instrumentation are
as follows:
1. Between scheduling and instruction selection, add code to increment
the counter for each block. The counters array doesn't yet exist at
this point, and allocation is disallowed, so at this point the code
refers to a special marker value.
2. During finalization of the code, allocate a BasicBlockProfilingData
object on the JS heap containing data equivalent to what is stored in
BasicBlockProfiler::Data. This includes a ByteArray that is big
enough to store the counters for each block.
3. Patch the reference in the BuiltinsConstantsTableBuilder so that
instead of referring to the marker object, it now refers to this
ByteArray. Also add the BasicBlockProfilingData object to a list that
is attached to the heap roots so it can be easily accessed for
printing.
Because these steps include modifying the BuiltinsConstantsTableBuilder,
this procedure is only applicable to builtins. Runtime-generated code
still uses raw pointers into std::vector instances. In order to keep
divergence between these code paths to a minimum, most work is done
referring to instances of BasicBlockProfiler::Data (the C++ class), and
functions are provided to copy back and forth between that type and
BasicBlockProfilingData (the JS heap object).
This change is intended only to make --turbo-profiling work consistently
on more kinds of functions, but with some further work, this data could
form the basis for:
- code coverage info for fuzzers, and/or
- hot-path info for profile-guided optimization.
Bug: v8:10470, v8:9119
Change-Id: Ib556a5bc3abe67cdaa2e3ee62702a2a08b11cb61
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2159738
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67944}
This reverts commit 5f28539599.
Reason for revert: presubmit failure
Original change's description:
> Move logging and diagnostics related source files
>
> This also introduces a COMMON_OWNERS file, which is derived from the
> current top-level OWNERS file. It is to be used for parts of the
> codebase that is not sensitive to domain-specific expertise.
>
> NOPRESUBMIT=true
> TBR=verwaest@chromium.org
>
> Bug: v8:9247
> Change-Id: I34a5eaa7cb1509a80d15094a2aceedd62665b17c
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1613987
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61600}
TBR=rmcilroy@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org,verwaest@chromium.org
Change-Id: I3827c3af4fd63b18aa48c49617f318a01746e813
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9247
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617247
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61601}
This also introduces a COMMON_OWNERS file, which is derived from the
current top-level OWNERS file. It is to be used for parts of the
codebase that is not sensitive to domain-specific expertise.
NOPRESUBMIT=true
TBR=verwaest@chromium.org
Bug: v8:9247
Change-Id: I34a5eaa7cb1509a80d15094a2aceedd62665b17c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1613987
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61600}
This CL is an experiment to get more performance data from the perf-bots
and will likely lead to regressions. The try-bots (see patcheset 9)
indicate some regressions, but it doesn't seem too bad.
Change-Id: Ia173ab20ee2a4904663db0f4ca2ffb196b203c77
Reviewed-on: https://chromium-review.googlesource.com/c/1319763
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57483}
This is a first step to make basic block profiling work in wasm. More
is needed, including eventually making the profiler thread safe.
Change-Id: Ic216c881a4ab5a633e147e5538bb405c32e687cd
Reviewed-on: https://chromium-review.googlesource.com/1150234
Commit-Queue: Stephan Herhut <herhut@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54728}
MachineType is now a class with two enum fields:
- MachineRepresentation
- MachineSemantic
Both enums are usable on their own, and this change switches some places from using MachineType to use just MachineRepresentation. Most notably:
- register allocator now uses just the representation.
- Phi and Select nodes only refer to representations.
Review URL: https://codereview.chromium.org/1513543003
Cr-Commit-Position: refs/heads/master@{#32738}
This moves all cctest files for the compiler to live in the same
namespace as the components they are testing. Hence we can avoid the
forbidden using directives pulling in entire namespaces.
From the Google C++ style guide: "You may not use a using-directive to
make all names from a namespace available". This would be covered by
presubmit linter checks if build/namespaces were not blacklisted.
R=bmeurer@chromium.org
Review URL: https://codereview.chromium.org/1424943004
Cr-Commit-Position: refs/heads/master@{#31671}
TurboFan is now a requirement and supported by all backends, so we don't
need those macros (plus all the machinery on top) anymore.
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1282763002
Cr-Commit-Position: refs/heads/master@{#30082}
