>> I may be interpreting this incorrectly, but are you >> busy-waiting on the ACPI Global Lock to become free? No. >Loop may be correctly waiting for the owner/pending bit to be >set, just checking, I don't remember all the bit values. Yes. __acpi_acquire_global_lock is basically a lock-try and set the pending bit on failure. bit 0 is the PENDING bit bit 1 is the OWNED bit so the loop is doing this: old = lock_value try_again: new = OWNED if (old & OWNED) new |= PENDING cmpxchg(lock_value, old, new) if (old != new) goto try_again; return(!(new & PENDING)) /* ACQUIRED or not */ so we loop only if somebody else changed the lock_value to be different from old at the same time this code did. if the lock were held, we simply set the pending bit and return that we failed to acquire the lock. -Len - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
