Linux 读/写被阻止的系统调用是否将进程置于TASK_不可中断或TASK_可中断状态？

如信号（7）手册页所述

如前所述，对以下接口之一（读、写）的阻塞调用被信号处理程序中断，如果使用SA_RESTART标志，则在信号处理程序返回后，调用将自动重新启动，这意味着在阻塞读/写系统调用的情况下，进程必须处于TASK_可中断状态

但当我试图找出使进程处于TASK_不可中断状态的阻塞系统调用时，我发现了和，在这两个地方都提到阻塞I/O调用（读、写）将使进程处于TASK_不可中断状态

这里还提到：

这有点让人困惑

我还想知道其他被阻止的系统调用，它们会使进程处于任务不可中断状态

对于

read（2）

或

write（2）

系列系统调用，睡眠类型取决于正在访问的文件类型。在您引用的文档中，“慢速”设备是指

读/写

将中断睡眠的设备，“快速”设备是指将不间断睡眠的设备（不间断睡眠状态称为

D

，表示“磁盘等待”，因为最初磁盘文件上的

读/写
是这种睡眠的最常见原因）

请注意，“阻塞”在技术上仅指可中断睡眠

几乎任何系统调用都可以进入不间断睡眠，因为当进程需要获取保护内部内核资源的锁时，就会发生这种情况。通常，这种不间断的睡眠是如此短暂，以至于你不会注意到它

   Interruption of system calls and library functions by signal handlers
       If a signal handler is invoked while a system call or library function call is blocked, then either:

       * the call is automatically restarted after the signal handler returns; or

       * the call fails with the error EINTR.

       Which  of  these  two behaviors occurs depends on the interface and whether or not the signal handler was established using the SA_RESTART flag (see sigaction(2)).  The details vary across UNIX systems; below, the details for
       Linux.

       If a blocked call to one of the following interfaces is interrupted by a signal handler, then the call will be automatically restarted after the signal handler returns if the SA_RESTART flag was used; otherwise the call  will
       fail with the error EINTR:

           * read(2),  readv(2),  write(2), writev(2), and ioctl(2) calls on "slow" devices.  A "slow" device is one where the I/O call may block for an indefinite time, for example, a terminal, pipe, or socket.  If an I/O call on a
             slow device has already transferred some data by the time it is interrupted by a signal handler, then the call will return a success status (normally, the number of bytes transferred).  Note that a (local) disk is not a
             slow device according to this definition; I/O operations on disk devices are not interrupted by signals.

The Uninterruptible state is mostly used by device drivers waiting for disk or network I/O. When the process
is sleeping uninterruptibly, signals accumulated during the sleep are noticed when the process returns from
the system call or trap. In Linux systems. the command ps -l uses the letter D in the state field (S) to
indicate that the process is in an Uninterruptible sleep state. In that case, the process state flag is set as
follows:
p->state = TASK_UNINTERRUPTABLE
LEARN MORE: Read more about D states in the Red Hat Knowledgebase:
https://access.redhat.com/knowledge/solutions/59989/