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kernel: Improve spinlock implementation 

atomic_or() and atomic_and() are not supported by x86 are need to be
emulated using CAS. Use atomic_get_and_set() and atomic_set() instead.
This commit is contained in:
Pawel Dziepak 2013-11-05 22:47:18 +01:00
parent 077c84eb27
commit 273f2f38cd
2 changed files with 14 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
headers/private/kernel/smp.h
View File

@ -76,7 +76,7 @@ int smp_intercpu_int_handler(int32 cpu);
static inline bool
try_acquire_spinlock_inline(spinlock* lock)
{
return atomic_or((int32*)lock, 1) == 0;
return atomic_get_and_set((int32*)lock, 1) == 0;
}
@ -92,7 +92,7 @@ acquire_spinlock_inline(spinlock* lock)
static inline void
release_spinlock_inline(spinlock* lock)
{
atomic_and((int32*)lock, 0);
atomic_set((int32*)lock, 0);
}

22
src/system/kernel/smp.cpp
View File

@ -313,7 +313,7 @@ try_acquire_spinlock(spinlock* lock)
if (atomic_add(&lock->lock, 1) != 0)
return false;
#else
if (atomic_or((int32*)lock, 1) != 0)
if (atomic_get_and_set((int32*)lock, 1) != 0)
return false;
# if DEBUG_SPINLOCKS
@ -353,7 +353,7 @@ acquire_spinlock(spinlock* lock)
process_all_pending_ici(currentCPU);
PAUSE();
}
if (atomic_or((int32*)lock, 1) == 0)
if (atomic_get_and_set((int32*)lock, 1) == 0)
break;
}
@ -364,7 +364,7 @@ acquire_spinlock(spinlock* lock)
} else {
#if DEBUG_SPINLOCKS
int32 oldValue;
oldValue = atomic_or((int32*)lock, 1);
oldValue = atomic_get_and_set((int32*)lock, 1);
if (oldValue != 0) {
panic("acquire_spinlock: attempt to acquire lock %p twice on "
"non-SMP system (last caller: %p, value %" B_PRId32 ")", lock,
@ -407,13 +407,13 @@ acquire_spinlock_nocheck(spinlock *lock)
PAUSE();
}
if (atomic_or((int32*)lock, 1) == 0)
if (atomic_get_and_set((int32*)lock, 1) == 0)
break;
}
#endif
} else {
#if DEBUG_SPINLOCKS
if (atomic_or((int32*)lock, 1) != 0) {
if (atomic_get_and_set((int32*)lock, 1) != 0) {
panic("acquire_spinlock_nocheck: attempt to acquire lock %p twice "
"on non-SMP system\n", lock);
}
@ -450,7 +450,7 @@ acquire_spinlock_cpu(int32 currentCPU, spinlock *lock)
process_all_pending_ici(currentCPU);
PAUSE();
}
if (atomic_or((int32*)lock, 1) == 0)
if (atomic_get_and_set((int32*)lock, 1) == 0)
break;
}
@ -461,7 +461,7 @@ acquire_spinlock_cpu(int32 currentCPU, spinlock *lock)
} else {
#if DEBUG_SPINLOCKS
int32 oldValue;
oldValue = atomic_or((int32*)lock, 1);
oldValue = atomic_get_and_set((int32*)lock, 1);
if (oldValue != 0) {
panic("acquire_spinlock_cpu(): attempt to acquire lock %p twice on "
"non-SMP system (last caller: %p, value %" B_PRId32 ")", lock,
@ -498,9 +498,11 @@ release_spinlock(spinlock *lock)
}
}
}
#else
if (atomic_and((int32*)lock, 0) != 1)
#elif DEBUG_SPINLOCKS
if (atomic_get_and_set((int32*)lock, 0) != 1)
panic("release_spinlock: lock %p was already released\n", lock);
#else
atomic_set((int32*)lock, 0);
#endif
} else {
#if DEBUG_SPINLOCKS
@ -508,7 +510,7 @@ release_spinlock(spinlock *lock)
panic("release_spinlock: attempt to release lock %p with "
"interrupts enabled\n", lock);
}
if (atomic_and((int32*)lock, 0) != 1)
if (atomic_get_and_set((int32*)lock, 0) != 1)
panic("release_spinlock: lock %p was already released\n", lock);
#endif
#if DEBUG_SPINLOCK_LATENCIES