The duration of this section needs to be controlled 5 Within minutes
Linux Under the asynchronous IO In fact, it doesn't use much , From the kernel 2.6 The version just started to introduce . Let's take a look at the process ：
User process initiation read After the operation , You can start doing other things right away . And on the other hand , from kernel The angle of , When it receives a asynchronous read after , First of all, it will return to , So it doesn't produce anything to the user process block. then ,kernel Waiting for the data to be ready , Then copy the data to user memory , When all this is done ,kernel A... Will be sent to the user process signal, Tell it read Operation completed .
