This patch merges the profiling functionality in the kernel with the
performance events mechanism. A profiler sample is now just another
perf event, rather than a dedicated thing.
Since perf events were already per-process, this now makes profiling
per-process as well.
Processes with perf events would already write out a perfcore.PID file
to the current directory on death, but since we may want to profile
a process and then let it continue running, recorded perf events can
now be accessed at any time via /proc/PID/perf_events.
This patch also adds information about process memory regions to the
perfcore JSON format. This removes the need to supply a core dump to
the Profiler app for symbolication, and so the "profiler coredump"
mechanism is removed entirely.
There's still a hard limit of 4MB worth of perf events per process,
so this is by no means a perfect final design, but it's a nice step
forward for both simplicity and stability.
Fixes#4848Fixes#4849
Let's adapt this class a bit better to how it's actually being used.
Instead of having valid/invalid states and storing an error in case
it's invalid, a MappedFile is now always valid, and the factory
function that creates it will return an OSError if mapping fails.
This commit gets rid of ELF::Loader entirely since its very ambiguous
purpose was actually to load executables for the kernel, and that is
now handled by the kernel itself.
This patch includes some drive-by cleanup in LibDebug and CrashDaemon
enabled by the fact that we no longer need to keep the ref-counted
ELF::Loader around.
If the percentage is 100, we were trying to get the heat gradient pixel
at (100, 0), which was one pixel past the end. Fix this by making the
heat gradient 101 pixels wide :^)
* AK: Add formatter for JsonValue.
* Inspector: Use new format functions.
* Profiler: Use new format functions.
* UserspaceEmulator: Use new format functions.
From a layering perspective, it's maybe a bit surprising that the
X86::SymbolProvider implementation also lives in LibX86, but since
everything depends on LibELF via LibC, and since all current
LibX86-based disassemblers want to use ELFSymbolProvider, it makes
some amount of sense to put it there.
