Mark mandatory elevator functions in the biodoc.txt

biodoc.txt mentions that elevator functions marked with * are mandatory, but
no function is marked with *. Mark the 3 functions which should be
implemented by any io scheduler.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Nikanth Karthikesan 2009-01-27 09:29:24 +01:00 committed by Jens Axboe
parent a229fc61ef
commit 7598909e3e
1 changed files with 3 additions and 3 deletions

View File

@ -954,14 +954,14 @@ elevator_allow_merge_fn called whenever the block layer determines
results in some sort of conflict internally, results in some sort of conflict internally,
this hook allows it to do that. this hook allows it to do that.
elevator_dispatch_fn fills the dispatch queue with ready requests. elevator_dispatch_fn* fills the dispatch queue with ready requests.
I/O schedulers are free to postpone requests by I/O schedulers are free to postpone requests by
not filling the dispatch queue unless @force not filling the dispatch queue unless @force
is non-zero. Once dispatched, I/O schedulers is non-zero. Once dispatched, I/O schedulers
are not allowed to manipulate the requests - are not allowed to manipulate the requests -
they belong to generic dispatch queue. they belong to generic dispatch queue.
elevator_add_req_fn called to add a new request into the scheduler elevator_add_req_fn* called to add a new request into the scheduler
elevator_queue_empty_fn returns true if the merge queue is empty. elevator_queue_empty_fn returns true if the merge queue is empty.
Drivers shouldn't use this, but rather check Drivers shouldn't use this, but rather check
@ -991,7 +991,7 @@ elevator_activate_req_fn Called when device driver first sees a request.
elevator_deactivate_req_fn Called when device driver decides to delay elevator_deactivate_req_fn Called when device driver decides to delay
a request by requeueing it. a request by requeueing it.
elevator_init_fn elevator_init_fn*
elevator_exit_fn Allocate and free any elevator specific storage elevator_exit_fn Allocate and free any elevator specific storage
for a queue. for a queue.