Commit Graph

5 Commits

Author SHA1 Message Date
Camillo Bruni
6956482764 [counters] Improve v8.execute histogram timer
- Mark uncommon timer-paths as V8_NOINLINE
- Add explicit LongTaskNestedTimedHistogramScope class
- Use explicit LongTaskRecordMode enum
- Mark a few more isolate methods as const
- Add more timer scopes:
  - Accessors::ArrayLengthSetter
  - v8::NewContext

Bug: v8:12498, chromium:1275056
Change-Id: I7896ee341c3c3a1fd5acf8f3f59347ff01dda9c0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3338258
Reviewed-by: Marja Hölttä <marja@chromium.org>
Auto-Submit: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78372}
2021-12-14 16:14:05 +00:00
Camillo Bruni
ce02d2f452 [api] Add LongTaskStats::v8_execute_us
The execute_us is now tied to the --slow-histograms flag.
This currently enabled on a small population as a persistent finch study
which should give us enough coverage for now.

Drive-by-fixes:
- Rename counter: execute_precise() to execute()
- Avoid Leave/Enter overhead in NestedTimedHistogramScope if the
  histogram is not enabled
- Only stop timers in debug mode for NestedTimedHistogramScope

Bug: chromium:1275056
Change-Id: Id6a492bdd68edb5194cb191c7083829a9f90283f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3320431
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78318}
2021-12-09 11:38:04 +00:00
Camillo Bruni
f688fe086f Reland "[counters] Fix reentrant timers for V8.Execute"
This is a reland of fffcbaea55

Additional fixes:
- Relax IsStarted DCHECKs in ElapsedTimer for paused_elapsed
- Add LogEventStatus enum in the API for better testing
- Rename Logger::StartEnd enum values to kXXX
- Add additional NestedTimedHistogramScope tests

Original change's description:
> [counters] Fix reentrant timers for V8.Execute
>
> This CL fixes a long standing issue where reentering TimedHistograms
> scopes would cause spurious measurements. Only the non-nested scopes
> yielded correct results.
>
> Due to the changed numbers, the V8.Execute histogram is renamed to
> V8.ExecuteMicroSeconds. Note that this histogram is also guarded
> behind the --slow-histograms flag due to the additional overhead.
>
> Unlike before, it does no longer include time for external callbacks
> and only measures self time. The following example illustrates the
> new behaviour:
>
> 1. Enter V8:           |--+.......+--| self-time: 4 units (reported)
> 2. Exit V8 (callback):    |-+...+-|    self-time: 2 units (ignored)
> 3. Re-enter V8:             |---|      self-time: 3 units (reported)
>
> This would result in 2 histogram entries with 4 time units for the first
> V8 slice and 3 units for the nested part. Note that the callback time
> itself is ignored.
>
> This CL attempts to clean up how TimedHistograms work:
> - Histogram: the base class
> - TimedHistograms: used for time-related histograms that are not nested
> - NestedTimeHistograms: Extends TimedHistograms and is used for nested
>   histograms
>
> This CL changes Histograms to not measure time themselves. Measurements
> happen in the *HistogramScopes:
> - BaseTimedHistogramScope: Base functionality
> - TimedHistogramScope: For non-nested measurements
> - NestedTimedHistogramScope: For nested measurements
> - PauseNestedTimedHistogramScope: Ignore time during a given scope.
>   This is used to pause timers during callbacks.
>
> Additional changes:
> - ExternalCallbackScope now contains a PauseNestedTimedHistogramScope
>   and always sets VMState<EXTERNAL>
>
> Bug: v8:11946
> Change-Id: I45e4b7ff77b5948b605dd50539044cb26222fa21
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3001345
> Reviewed-by: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
> Reviewed-by: Victor Gomes <victorgomes@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#76111}

Bug: v8:11946
Change-Id: Ic2eef7456fbc245febcf780b23418f6ab0bebdb7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3080566
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76180}
2021-08-09 18:41:50 +00:00
Leszek Swirski
a12c6fa2ea Revert "[counters] Fix reentrant timers for V8.Execute"
This reverts commit fffcbaea55.

Reason for revert: Breaks in Chromium (e.g. https://ci.chromium.org/p/v8/builders/ci/Linux%20V8%20FYI%20Release%20%28NVIDIA%29)

Original change's description:
> [counters] Fix reentrant timers for V8.Execute
>
> This CL fixes a long standing issue where reentering TimedHistograms
> scopes would cause spurious measurements. Only the non-nested scopes
> yielded correct results.
>
> Due to the changed numbers, the V8.Execute histogram is renamed to
> V8.ExecuteMicroSeconds. Note that this histogram is also guarded
> behind the --slow-histograms flag due to the additional overhead.
>
> Unlike before, it does no longer include time for external callbacks
> and only measures self time. The following example illustrates the
> new behaviour:
>
> 1. Enter V8:           |--+.......+--| self-time: 4 units (reported)
> 2. Exit V8 (callback):    |-+...+-|    self-time: 2 units (ignored)
> 3. Re-enter V8:             |---|      self-time: 3 units (reported)
>
> This would result in 2 histogram entries with 4 time units for the first
> V8 slice and 3 units for the nested part. Note that the callback time
> itself is ignored.
>
> This CL attempts to clean up how TimedHistograms work:
> - Histogram: the base class
> - TimedHistograms: used for time-related histograms that are not nested
> - NestedTimeHistograms: Extends TimedHistograms and is used for nested
>   histograms
>
> This CL changes Histograms to not measure time themselves. Measurements
> happen in the *HistogramScopes:
> - BaseTimedHistogramScope: Base functionality
> - TimedHistogramScope: For non-nested measurements
> - NestedTimedHistogramScope: For nested measurements
> - PauseNestedTimedHistogramScope: Ignore time during a given scope.
>   This is used to pause timers during callbacks.
>
> Additional changes:
> - ExternalCallbackScope now contains a PauseNestedTimedHistogramScope
>   and always sets VMState<EXTERNAL>
>
> Bug: v8:11946
> Change-Id: I45e4b7ff77b5948b605dd50539044cb26222fa21
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3001345
> Reviewed-by: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
> Reviewed-by: Victor Gomes <victorgomes@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#76111}

Bug: v8:11946
Change-Id: I954de1afbabf101fb5d4f52eca0d3b80a723385b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3077153
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Owners-Override: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76138}
2021-08-06 14:31:44 +00:00
Camillo Bruni
fffcbaea55 [counters] Fix reentrant timers for V8.Execute
This CL fixes a long standing issue where reentering TimedHistograms
scopes would cause spurious measurements. Only the non-nested scopes
yielded correct results.

Due to the changed numbers, the V8.Execute histogram is renamed to
V8.ExecuteMicroSeconds. Note that this histogram is also guarded
behind the --slow-histograms flag due to the additional overhead.

Unlike before, it does no longer include time for external callbacks
and only measures self time. The following example illustrates the
new behaviour:

1. Enter V8:           |--+.......+--| self-time: 4 units (reported)
2. Exit V8 (callback):    |-+...+-|    self-time: 2 units (ignored)
3. Re-enter V8:             |---|      self-time: 3 units (reported)

This would result in 2 histogram entries with 4 time units for the first
V8 slice and 3 units for the nested part. Note that the callback time
itself is ignored.

This CL attempts to clean up how TimedHistograms work:
- Histogram: the base class
- TimedHistograms: used for time-related histograms that are not nested
- NestedTimeHistograms: Extends TimedHistograms and is used for nested
  histograms

This CL changes Histograms to not measure time themselves. Measurements
happen in the *HistogramScopes:
- BaseTimedHistogramScope: Base functionality
- TimedHistogramScope: For non-nested measurements
- NestedTimedHistogramScope: For nested measurements
- PauseNestedTimedHistogramScope: Ignore time during a given scope.
  This is used to pause timers during callbacks.

Additional changes:
- ExternalCallbackScope now contains a PauseNestedTimedHistogramScope
  and always sets VMState<EXTERNAL>

Bug: v8:11946
Change-Id: I45e4b7ff77b5948b605dd50539044cb26222fa21
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3001345
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76111}
2021-08-05 10:03:08 +00:00