BLK_START_PLUG(9)                         Block Devices                         BLK_START_PLUG(9)



NAME
       blk_start_plug - initialize blk_plug and track it inside the task_struct

SYNOPSIS
       void blk_start_plug(struct blk_plug * plug);

ARGUMENTS
       plug
           The struct blk_plug that needs to be initialized

DESCRIPTION
       Tracking blk_plug inside the task_struct will help with auto-flushing the pending I/O
       should the task end up blocking between blk_start_plug and blk_finish_plug. This is
       important from a performance perspective, but also ensures that we don't deadlock. For
       instance, if the task is blocking for a memory allocation, memory reclaim could end up
       wanting to free a page belonging to that request that is currently residing in our private
       plug. By flushing the pending I/O when the process goes to sleep, we avoid this kind of
       deadlock.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                         BLK_START_PLUG(9)