如何选择 mq-deadline 调度器？

Question

我正在尝试选择新的 mq-deadline io 调度程序，但它似乎不可用。

$ cat /sys/block/sda/queue/scheduler 
noop [deadline] 

核心：

$ uname -a
Linux pluto 4.11.6-zenbook #1 SMP Wed Jun 21 09:39:34 EDT 2017 x86_64 GNU/Linux

留言：

$ sudo dmesg|grep deadline
[    0.077863] TSC deadline timer enabled
[    1.383260] io scheduler deadline registered (default)
[    1.383261] io scheduler mq-deadline registered

Answer 1

您还需要启用CONFIG_SCSI_MQ_DEFAULT

Symbol: SCSI_MQ_DEFAULT [=y]
Type  : boolean
Prompt: SCSI: use blk-mq I/O path by default
  Location:
    -> Device Drivers
      -> SCSI device support
  Defined at drivers/scsi/Kconfig:50
  Depends on: SCSI [=y]

瞧

$ cat /sys/block/sda/queue/scheduler
[mq-deadline] none