kern: improve KLightLock accuracy

This commit is contained in:
Michael Scire 2020-07-25 04:28:44 -07:00 committed by SciresM
parent 1448068b69
commit 4ac94e9179
3 changed files with 15 additions and 8 deletions

View file

@ -31,15 +31,18 @@ namespace ams::kern {
MESOSPHERE_ASSERT_THIS(); MESOSPHERE_ASSERT_THIS();
const uintptr_t cur_thread = reinterpret_cast<uintptr_t>(GetCurrentThreadPointer()); const uintptr_t cur_thread = reinterpret_cast<uintptr_t>(GetCurrentThreadPointer());
const uintptr_t cur_thread_tag = (cur_thread | 1);
while (true) { while (true) {
uintptr_t old_tag = this->tag.load(std::memory_order_relaxed); uintptr_t old_tag = this->tag.load(std::memory_order_relaxed);
while (!this->tag.compare_exchange_weak(old_tag, (old_tag == 0) ? cur_thread : old_tag | 1, std::memory_order_acquire)) { while (!this->tag.compare_exchange_weak(old_tag, (old_tag == 0) ? cur_thread : old_tag | 1, std::memory_order_acquire)) {
/* ... */ if ((old_tag | 1) == cur_thread_tag) {
return;
}
} }
if ((old_tag == 0) || ((old_tag | 1) == (cur_thread | 1))) { if ((old_tag == 0) || ((old_tag | 1) == cur_thread_tag)) {
break; break;
} }
@ -52,9 +55,11 @@ namespace ams::kern {
const uintptr_t cur_thread = reinterpret_cast<uintptr_t>(GetCurrentThreadPointer()); const uintptr_t cur_thread = reinterpret_cast<uintptr_t>(GetCurrentThreadPointer());
uintptr_t expected = cur_thread; uintptr_t expected = cur_thread;
if (!this->tag.compare_exchange_weak(expected, 0, std::memory_order_release)) { do {
this->UnlockSlowPath(cur_thread); if (expected != cur_thread) {
} return this->UnlockSlowPath(cur_thread);
}
} while (!this->tag.compare_exchange_weak(expected, 0, std::memory_order_release));
} }
void LockSlowPath(uintptr_t owner, uintptr_t cur_thread); void LockSlowPath(uintptr_t owner, uintptr_t cur_thread);

View file

@ -38,6 +38,7 @@ namespace ams::kern {
if (AMS_LIKELY(cur_thread->GetState() == KThread::ThreadState_Runnable)) { if (AMS_LIKELY(cur_thread->GetState() == KThread::ThreadState_Runnable)) {
cur_thread->SetState(KThread::ThreadState_Waiting); cur_thread->SetState(KThread::ThreadState_Waiting);
} }
if (owner_thread->IsSuspended()) { if (owner_thread->IsSuspended()) {
owner_thread->ContinueIfHasKernelWaiters(); owner_thread->ContinueIfHasKernelWaiters();
} }
@ -75,6 +76,10 @@ namespace ams::kern {
if (AMS_LIKELY(next_owner->GetState() == KThread::ThreadState_Waiting)) { if (AMS_LIKELY(next_owner->GetState() == KThread::ThreadState_Waiting)) {
next_owner->SetState(KThread::ThreadState_Runnable); next_owner->SetState(KThread::ThreadState_Runnable);
} }
if (next_owner->IsSuspended()) {
next_owner->ContinueIfHasKernelWaiters();
}
} }
/* We may have unsuspended in the process of acquiring the lock, so we'll re-suspend now if so. */ /* We may have unsuspended in the process of acquiring the lock, so we'll re-suspend now if so. */

View file

@ -95,9 +95,6 @@ namespace ams::kern::svc {
} }
Result UnmapMemory(uintptr_t dst_address, uintptr_t src_address, size_t size) { Result UnmapMemory(uintptr_t dst_address, uintptr_t src_address, size_t size) {
/* Log the call parameters for debugging. */
MESOSPHERE_LOG("UnmapMemory(%zx, %zx, %zx)\n", dst_address, src_address, size);
/* Validate that addresses are page aligned. */ /* Validate that addresses are page aligned. */
R_UNLESS(util::IsAligned(dst_address, PageSize), svc::ResultInvalidAddress()); R_UNLESS(util::IsAligned(dst_address, PageSize), svc::ResultInvalidAddress());
R_UNLESS(util::IsAligned(src_address, PageSize), svc::ResultInvalidAddress()); R_UNLESS(util::IsAligned(src_address, PageSize), svc::ResultInvalidAddress());