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Kernel/SMP: Change critical sections to not disable interrupts

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Leave interrupts enabled so that we can still process IRQs. Critical
sections should only prevent preemption by another thread.

Co-authored-by: Tom <tomut@yahoo.com>
This commit is contained in:
Andreas Kling 2021-08-10 01:56:21 +02:00
parent 364134ad4b
commit 0a02496f04
6 changed files with 42 additions and 60 deletions
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13
Kernel/Thread.cpp
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@ -388,8 +388,7 @@ void Thread::die_if_needed()
// Now leave the critical section so that we can also trigger the
// actual context switch
u32 prev_flags;
Processor::clear_critical(prev_flags, false);
Processor::clear_critical();
dbgln("die_if_needed returned from clear_critical!!! in irq: {}", Processor::current().in_irq());
// We should never get here, but the scoped scheduler lock
// will be released by Scheduler::context_switch again
@ -420,10 +419,9 @@ void Thread::yield_assuming_not_holding_big_lock()
// Disable interrupts here. This ensures we don't accidentally switch contexts twice
InterruptDisabler disable;
Scheduler::yield(); // flag a switch
u32 prev_flags;
u32 prev_crit = Processor::clear_critical(prev_flags, true);
u32 prev_critical = Processor::clear_critical();
// NOTE: We may be on a different CPU now!
Processor::restore_critical(prev_crit, prev_flags);
Processor::restore_critical(prev_critical);
}
void Thread::yield_and_release_relock_big_lock()
@ -451,13 +449,12 @@ void Thread::relock_process(LockMode previous_locked, u32 lock_count_to_restore)
// flagged by calling Scheduler::yield above.
// We have to do it this way because we intentionally
// leave the critical section here to be able to switch contexts.
u32 prev_flags;
u32 prev_crit = Processor::clear_critical(prev_flags, true);
u32 prev_critical = Processor::clear_critical();
// CONTEXT SWITCH HAPPENS HERE!
// NOTE: We may be on a different CPU now!
Processor::restore_critical(prev_crit, prev_flags);
Processor::restore_critical(prev_critical);
if (previous_locked != LockMode::Unlocked) {
// We've unblocked, relock the process if needed and carry on.