PS contains some state that is always valid, and some state that is only valid
when the profiler is active. This patch does the following.
- Splits PS into two parts for the two kinds of state: CorePS and ActivePS.
- Moves gPS (now split in two) into CorePS and ActivePS, as static instances,
to improve encapsulation. This required changing all the state getters and
setters into static methods.
- Existence tests for CorePS and ActivePS are now done via the Exists()
methods.
Advantages of this change:
- It's now clear which parts of the global state (most of it!) are valid only
when the profiler is active, and we don't have to invalidate those parts with
zero/null/false when the profiler stops.
- Better OOP: more use of constructors and destructors, and more |const| to
indicate what state is immutable.
- With the old code there were some places where the order of things required
care, but with the new code it's not possible to get the order wrong.
TimeStamp::ProcessCreations()'s aIsInconsistent outparam is ignored by the
majority of its caller. This patch makes it optional. Notably, this makes
ProcessCreation() easier to use in a constructor's initializer list.
On x86_64-Linux, LUL currently can only unwind frames for which CFI unwind data
is available. This causes a noticeable number of junk samples in the profiler,
characterised by failures at transition points between JIT and native frame
sequences. This patch allows LUL to try recovering the previous frame using
frame pointer chasing in the case where CFI isn't present. This allows LUL to
unwind through or jump over interleaved JIT frames, because, respectively:
* The baseline JIT produces frame-pointerised code.
* If the profiler is enabled, IonMonkey doesn't produce frame-pointerised code,
but also doesn't change the frame pointer register value. It can use the
frame pointer if profiling is disabled, but that's irrelevant here.
The patch also adds counts of FP-recovered frames to LUL's statistics printing,
to make it possible to assess how often this feature is used.
We can lower the eslint cyclomatic complexity threshold in some directories without adding eslint suppression comments in any .js source files. We need to specify the complexity rule in accessible/.eslintrc because it doesn't inherit the mozilla/recommended rules. eslint's default complexity threshold is 20.
Also bump the eslint-plugin-mozilla version because we modified the mozilla/recommended rules.
MozReview-Commit-ID: 57T4gAjPH7z
eslint's default max-nested-callbacks threshold is 10, but now we make it an error. We could further lower the max-nested-callbacks threshold globally to 8, like browser/.eslintrc.js, but that would require adding suppression comments in (two) more .js test files. 10 seems good enough for now since it's the eslint default.
We need to specify max-nested-callbacks in accessible/.eslintrc because it doesn't inherit the mozilla/recommended rules.
Also bump the eslint-plugin-mozilla version because we modified the mozilla/recommended rules.
MozReview-Commit-ID: JA41vsi4U7j
We've had 4 submissions in 2017. jgriffin and I agreed that it was a
failed experiment and we should either abandon it or figure out how
to increase participation. Since nobody is available to improve it,
I'm inclined to just delete it. If we want to bring it back, it is
always in version control.
MozReview-Commit-ID: AizkZxjQ8IJ
AddPseudoEntry() has a single callsite which always passes nullptr for the
last argument. This means that js::ProfilingGetPC() is never called, and so can
be removed. (Even if it was called, it always returns nullptr because ipToPC()
always returns nullptr!)
Remove the definition of sig_safe_t, which is only used by PseudoStack,
and replace the uses with mozilla::Atomic<uint32_t>.
MozReview-Commit-ID: GcPd9R94Vci
This option turns on a frame counter that is shown in the top left corner via a
QR code. It was designed to be used in video recordings of B2G phones.
It no longer seems useful, so this patch removes it.
* * *
Bug 1357298 - Remove all traces of frame numbers and power from the profiler output. r=mstange.
clang's -Wcomma warning warns about suspicious use of the comma operator such as between two statements.
tools/profiler/lul/LulDwarf.cpp:604:15: warning: possible misuse of comma operator here [-Wcomma]
MozReview-Commit-ID: 6ZP79hgtrAD
The patch adds a missing |delete|. (This leak only occurred when the
"mainthreadio" feature was enabled, which is not the default.)
The patch also makes the unregistering of the interpose observer conditional on
there being one in the first place, avoiding a harmless but useless
unregistering of |nullptr|.
For reasons related to the architecture of the Gecko Profiler in previous years,
which are no longer relevant, LUL will only unwind through the first 32KB of
stack. This is mostly harmless, since most stacks are smaller than 4KB, per
measurements today, but occasionally they go above 32KB, causing unwinding to
stop prematurely.
This patch changes the max size to 160KB, and documents the rationale for
copying the stack and unwinding, rather than unwinding in place. 160KB is big
enough for all stacks observed in several minutes of profiling all threads at
1KHz.
Everything depending on the widget being gonk can go away, as well as
everything depending on MOZ_AUDIO_CHANNEL_MANAGER, which was only
defined on gonk builds under b2g/ (which goes away in bug 1357326).
