Encountered in 不如帰大乱 when `HOS-3` is awoken at the same time as `HOS-0` called `SvcSetThreadCoreMask` resulting in a deadlock where `HOS-0` owns `HOS-3`'s `coreMigrationMutex` while `HOS-3` owns the core mutex with the both of them attempting to lock the other mutex
Add Tracing for SVCs, Services, NVDRV, and Synchronization Primitives. In addition, fix `TRACE_EVENT_END("guest")` being emitted when a signal is received while being in the guest rather than host which would cause an exception. This commit also disables warnings for the Perfetto library as we do not control fixing them.
The following scheduler bugs were fixed:
* It was assumed that all non-cooperative `Rotate` calls were from a preemptive yield and changed the state of `KThread::isPreempted` incorrectly which could lead to UB, an example of a scenario with it would be:
* * Preemptive thread A gets a signal to yield from cooperative thread B due to it being ready to schedule and higher priority
* * A complies with this request but there's an assumption that the signal was actually from it's preemption timer therefore it doesn't reset it (As it isn't required if the timer was responsible for the signal)
* * A receives the actual preemption signal a while later, causing UB as the signal handler is invoked twice
* `Scheduler::UpdatePriority`
* * A check for `currentIt == core->queue.begin()` existed which caused an incorrect early return
* * The preemption timer was armed correctly when a priority transition from cooperative priority -> preemption priority occurred but not disarmed when a transition from preemption priority -> cooperative priority occurred
* * The timer was unnecessarily disarmed in the case of updating the priority of a non-running thread, this isn't as much a bug as it is just pointless
* Priority inheritance in `KProcess::MutexLock` is fundamentally broken as it performs UB with `waitThread` being accessed prior to being assigned
* When a thread sets its own priority using `SvcSetThreadCoreMask` and its current core is no longer in the affinity mask, it wouldn't actually move to the new thread until the next time the thread is load balanced
This addresses all CR comments including more codebase-wide changes arising from certain review comments like proper usage of its/it's and consistent contraction of it is into it's.
An overhaul was made to the presentation and formatting of `KThread.h` and `LoadBalance` works has been superseded by `GetOptimalCoreForThread` which can be used alongside `InsertThread` or `MigrateToCore`. It makes the API far more atomic and neater. This was a major point of contention for the design prior, it's simplified some code and potentially improved performance.
The case of a thread not being in the core queue during a non-cooperative core affinity change would break things as the thread was non-conditionally removed and inserted, this has been fixed by adding a check to see if the thread exists in the core's queue prior to migration. In addition, `yieldWithCoreMigration` was broken by the previous commit as the fallthrough was intentional and removing it cause core migration without a yield which led to breakage in certain circumstances. The mutex locking logic was also improved in `ConditionalVariableWait` to use atomics in a more effective manner with less atomic operations being performed overall.
We did not support migration of threads which were running in a non-cooperative manner, this was partially due to the dependence on per-core conditional variables rather than per-thread which made this harder to do programmatically. This has been fixed by moving to per-thread cvars and therefore the limitation can be removed, this feature is used by Unity games.
