[KLUG Members] What is the meaning of these?

[Adam Tauno Williams]

> aio/0,ato/0,events/0,kacpid,kblocked/0,pdflush,scsi_eh_o,migration/0 without
> any command evoked. What are all these command or process resoponcible?

These kernel subsystems.

aio = Asyncronous I/O event queue.

ato = Haven't seen this one

events = This informs the kernel it needs to schedule some work or
process due to <shock> and event such as a new device appearing on the
USB bus, or the machine (a laptop) getting plugged into AC power, etc...
kacpid = This is the kernel side of ACPI support (ACPI is actually a
really complicated spec vs. the simple old APM)

kblocked = Used as a queue for block events, allowing things to be
deferred in an attempt to reduce latency introduced when performing
block events.

pdflush = This is used to track and dispose of dirty memory pages.  The
kernel will invoke this subthread to do its business when the dirty
ration has been exceeded

scsi_eh_0 = You see one of these worker threads for each SCSI
bus/adapter.  For instance, on my database server (with 5 SCSI adapters)
I see....
  225 ?        S      0:00 [scsi_eh_0]
  239 ?        S      0:00 [scsi_eh_1]
  307 ?        S      0:00 [scsi_eh_2]
  312 ?        S      0:00 [scsi_eh_3]
  319 ?        S      0:00 [scsi_eh_4]

migration/0 = This is part of MD (software raid), and one assumes from
its name that it handles hot adds, removes, and rebuilding spares.