yuzu/yuzu-emu.github.io
1
0
Fork 0
mirror of https://github.com/yuzu-emu/yuzu-emu.github.io.git synced 2025-06-08 13:27:25 +00:00
Code Issues Packages Projects Releases Wiki Activity

mutex

Browse source
This commit is contained in:
Matías Locatti 2022-06-10 18:16:35 -03:00 committed by GitHub
parent d0c867b66b
commit f537b3d9f1
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 30 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
site/content/entry/yuzu-progress-report-may-2022/index.md
View file

@ -127,6 +127,36 @@ In the meantime, toastUnlimited {{< gh-hovercard "8379" "blocked the extension"
[asLody](https://github.com/asLody) {{< gh-hovercard "8311" "implemented stencil fixes when two faces are disabled." >}}
This has the potential to improve rendering in native OpenGL games.
## HLE Improvements
In software engineering, a spinlock is a lock that causes a thread trying to acquire it to simply wait in a loop
("spin") while repeatedly checking whether the lock is available.
{{< imgs
"./spinlock.png| Example of a spinlock"
>}}
On the other hand, the word "mutex" stands for an object providing `MUTual EXclusion` between threads.
Mutex ensures that only one thread has access to a critical section or data by using operations like a lock and unlock.
A thread that acquires the lock of mutex can use the critical section while other threads must wait till the lock is released.
{{< imgs
"./mutex.png| Example of a mutex"
>}}
In theory, when a thread tries to lock a mutex and it does not succeed, because the mutex is already locked, it will go to sleep, immediately allowing another thread to run.
It will continue to sleep until being woken up, which will be the case once the mutex is being unlocked by whatever thread was holding the lock before.
But when a thread tries to lock a spinlock and it does not succeed, it will continuously re-try locking it, until it finally succeeds; thus it will not allow another thread to take its place until the OS forces it to timeout.
Hence, polling on a spinlock will constantly waste CPU time and if the lock is held for a longer amount of time, this will waste a lot more CPU time and it would have been much better if the thread was sleeping instead.
However in practice, most modern operating systems (Windows/Linux) use hybrid mutexes and hybrid spinlocks.
So spinlocks are fine on systems with tons of cores, as it's not a big deal for host threads to spin.
On low core counts, you really start starving the system by doing that, whereas a mutex will allow another thread to be scheduled on that core/thread.
Thus {{< gh-hovercard "8172" "by moving from spinlocks to mutexes," >}} we were able to improve how yuzu runs on systems with low core counts.
Our testing results showed that yuzu is now much more usable on 4 thread systems.
## UI changes
[Docteh](https://github.com/Docteh) has been very helpful with some translation holes we had for a while.