blk-mq: batching request allocation

problems

multiple queues

just begining with SQ support

how to decide if current is in ioc_batching

io context instance

how to avoid other context's interference

one active ioc batching

new request allocation from other io context

background

sched

wakeup

WQ_FLAG_EXCLUSIVE

ideas

ioc batching

single wait_state

detect queue full

check if there are waiters

test

test sequential IO on sata

set after being waken up

set for the 1st full

continue to allocate for this context only

block allocation from other contexts

how to handle during SSD flag

only done for registered queue?

why does sd_probe call two sd_revalidate_disk?

splitting IO may be interrupted by other context

done

lock

request_queue lock?