// wdm.h
VOID KefAcquireSpinLockAtDpcLevel(
PKSPIN_LOCK SpinLock
);
View the official Windows Driver Kit DDI reference
No description available.
The KefAcquireSpinLockAtDpcLevel routine acquires a spin lock when the caller is already running at IRQL >= DISPATCH_LEVEL.
SpinLock
Pointer to an initialized KSPIN_LOCK spin lock for which the caller must provide the storage. The spin lock must be from non-paged pool.
Drivers call KefAcquireSpinLockAtDpcLevel instead of KeAcquireSpinLock for better driver performance if and only if they are already running at an IRQL of DISPATCH_LEVEL or above.
If a driver is running at IRQL <= APC_LEVEL, it should call KeAcquireSpinLock to have IRQL raised by that routine. KefAcquireSpinLockAtDpcLevel assumes the caller is already running at IRQL >= DISPATCH_LEVEL, so no raise is necessary.
The caller should release the spin lock with KefReleaseSpinLockFromDpcLevel as quickly as possible.
For more information about spin locks, see Spin Locks.