#define _raw_spin_lock(lock) __LOCK(lock) __LOCK函数代码如下: #define __LOCK(lock) \ do { preempt_disable(); ___LOCK(lock); } while (0) 可以看出,首先禁止内核抢占。然后调用 #define ___LOCK(lock) \ do { __acquire(lock); (void)(lock); } while (0) 从上面的代码可以看出,单...
spin_lock_mutex(&lock->wait_lock, flags); /* * Once more, try to acquire the lock. Only try-lock the mutex if * it is unlocked to reduce unnecessary xchg() operations. */ if (!mutex_is_locked(lock) && (atomic_xchg(&lock->count, 0) == 1)) goto skip_wait; debug_mutex_lock...
[<c006c55c>] lock_acquire+0xf4/0x190[<c05b09e4>] mutex_lock_nested+0x90/0x480[<bf000080>] lockdep_test_worker+0x24/0x58[mutexlock][<c0041138>] process_one_work+0x1f0/0x60c[<c0041fd0>] worker_thread+0x54/0x530[<c0046ee0>] kthread+0x100/0x118[<c000ed50>] ret_from_fork+0...
staticinlinevoiddo_raw_spin_lock(raw_spinlock_t*lock)__acquires(lock){__acquire(lock);arch_spin_lock(&lock->raw_lock);} arch_spin_lock函数的源代码: 代码语言:javascript 复制 static__always_inlinevoidarch_spin_lock(arch_spinlock_t*lock){register struct __raw_tickets inc={.tail=TICKET_L...
如果在代码中出现了不平衡的状况，那么在Sparse的检测中就会报警。如果要使用Sparse检测功能就需要安装sparse工具（参考相关安装方法），然后编译内核 make zImage C=1 (C=1，只检测新编译的文件，C=2是查所有文件)Sparse会定义__CHECKER__，如果你没有使用sparse工具，__acquire(lock)则定义为空 ...
假设有两处代码(比如不同线程的两个函数 thread_P 和 thread_Q)都要获取两个锁(分别为 lockA 和 lockB),如果 thread_P 持有 lockA 后再去获取 lockB,而此时恰好由 thread_Q 持有 lockB 且它也正在尝试获取 lockA,那么此时就是处于死锁的状态,这是一个最简单的死锁例子,也即所谓的 AB-BA 死锁。
stack backtrace:---栈回溯信息:可以看出从lockdep_test_init->_raw_spin_lock->lock_acquire的调用路径。 CPU: 0 PID: 658 Comm: insmod Tainted: G O 4.0.0+ #87 Hardware name: ARM-Versatile Express [<c00171b4>] (unwind_backtrace) from [<c0012e7c>...
#define ___LOCK(lock) \ do { __acquire(lock); (void)(lock); } while (0) # define __acquire(x) (void)0 SMP多核情况下,除了关抢占,还需要用到独占(原子)的汇编指令操作变量,如下: kernel\locking\spinlock.c include\linux\spinlock_api_smp.h ...
#ifdef CONFIG_LOCK_KERNEL #define kernel_locked()(current->lock_depth >= 0) extern void __lockfunc lock_kernel(void)__acquires(kernel_lock); extern void __lockfunc unlock_kernel(void)__releases(kernel_lock); #else #define lock_kernel()do { } while(0) ...
1 #define local_lock(lock) __local_lock(lock) 2 3include/linux/local_lock_internal.h 4 #ifdef CONFIG_PREEMPT_RT 5 6 #define __local_lock(lock) \ 7 do { \ 8 migrate_disable(); \ 9 local_lock_acquire(this_cpu_ptr(lock)); \ ...