diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
---|---|---|
committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/block/noop-iosched.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/block/noop-iosched.c')
-rw-r--r-- | kernel/block/noop-iosched.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/kernel/block/noop-iosched.c b/kernel/block/noop-iosched.c new file mode 100644 index 000000000..3de89d469 --- /dev/null +++ b/kernel/block/noop-iosched.c @@ -0,0 +1,124 @@ +/* + * elevator noop + */ +#include <linux/blkdev.h> +#include <linux/elevator.h> +#include <linux/bio.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> + +struct noop_data { + struct list_head queue; +}; + +static void noop_merged_requests(struct request_queue *q, struct request *rq, + struct request *next) +{ + list_del_init(&next->queuelist); +} + +static int noop_dispatch(struct request_queue *q, int force) +{ + struct noop_data *nd = q->elevator->elevator_data; + + if (!list_empty(&nd->queue)) { + struct request *rq; + rq = list_entry(nd->queue.next, struct request, queuelist); + list_del_init(&rq->queuelist); + elv_dispatch_sort(q, rq); + return 1; + } + return 0; +} + +static void noop_add_request(struct request_queue *q, struct request *rq) +{ + struct noop_data *nd = q->elevator->elevator_data; + + list_add_tail(&rq->queuelist, &nd->queue); +} + +static struct request * +noop_former_request(struct request_queue *q, struct request *rq) +{ + struct noop_data *nd = q->elevator->elevator_data; + + if (rq->queuelist.prev == &nd->queue) + return NULL; + return list_entry(rq->queuelist.prev, struct request, queuelist); +} + +static struct request * +noop_latter_request(struct request_queue *q, struct request *rq) +{ + struct noop_data *nd = q->elevator->elevator_data; + + if (rq->queuelist.next == &nd->queue) + return NULL; + return list_entry(rq->queuelist.next, struct request, queuelist); +} + +static int noop_init_queue(struct request_queue *q, struct elevator_type *e) +{ + struct noop_data *nd; + struct elevator_queue *eq; + + eq = elevator_alloc(q, e); + if (!eq) + return -ENOMEM; + + nd = kmalloc_node(sizeof(*nd), GFP_KERNEL, q->node); + if (!nd) { + kobject_put(&eq->kobj); + return -ENOMEM; + } + eq->elevator_data = nd; + + INIT_LIST_HEAD(&nd->queue); + + spin_lock_irq(q->queue_lock); + q->elevator = eq; + spin_unlock_irq(q->queue_lock); + return 0; +} + +static void noop_exit_queue(struct elevator_queue *e) +{ + struct noop_data *nd = e->elevator_data; + + BUG_ON(!list_empty(&nd->queue)); + kfree(nd); +} + +static struct elevator_type elevator_noop = { + .ops = { + .elevator_merge_req_fn = noop_merged_requests, + .elevator_dispatch_fn = noop_dispatch, + .elevator_add_req_fn = noop_add_request, + .elevator_former_req_fn = noop_former_request, + .elevator_latter_req_fn = noop_latter_request, + .elevator_init_fn = noop_init_queue, + .elevator_exit_fn = noop_exit_queue, + }, + .elevator_name = "noop", + .elevator_owner = THIS_MODULE, +}; + +static int __init noop_init(void) +{ + return elv_register(&elevator_noop); +} + +static void __exit noop_exit(void) +{ + elv_unregister(&elevator_noop); +} + +module_init(noop_init); +module_exit(noop_exit); + + +MODULE_AUTHOR("Jens Axboe"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("No-op IO scheduler"); |