block, cfq: reorganize cfq_io_context into generic and cfq specific parts
Currently io_context and cfq logics are mixed without clear boundary.
Most of io_context is independent from cfq but cfq_io_context handling
logic is dispersed between generic ioc code and cfq.
cfq_io_context represents association between an io_context and a
request_queue, which is a concept useful outside of cfq, but it also
contains fields which are useful only to cfq.
This patch takes out generic part and put it into io_cq (io
context-queue) and the rest into cfq_io_cq (cic moniker remains the
same) which contains io_cq. The following changes are made together.
* cfq_ttime and cfq_io_cq now live in cfq-iosched.c.
* All related fields, functions and constants are renamed accordingly.
* ioc->ioc_data is now "struct io_cq *" instead of "void *" and
renamed to icq_hint.
This prepares for io_context API cleanup. Documentation is currently
sparse. It will be added later.
Changes in this patch are mechanical and don't cause functional
change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index e23c797..dc5e69d 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -46,7 +46,7 @@
/*
* Slow path for ioc release in put_io_context(). Performs double-lock
- * dancing to unlink all cic's and then frees ioc.
+ * dancing to unlink all icq's and then frees ioc.
*/
static void ioc_release_fn(struct work_struct *work)
{
@@ -56,11 +56,10 @@
spin_lock_irq(&ioc->lock);
- while (!hlist_empty(&ioc->cic_list)) {
- struct cfq_io_context *cic = hlist_entry(ioc->cic_list.first,
- struct cfq_io_context,
- cic_list);
- struct request_queue *this_q = cic->q;
+ while (!hlist_empty(&ioc->icq_list)) {
+ struct io_cq *icq = hlist_entry(ioc->icq_list.first,
+ struct io_cq, ioc_node);
+ struct request_queue *this_q = icq->q;
if (this_q != last_q) {
/*
@@ -89,8 +88,8 @@
continue;
}
ioc_release_depth_inc(this_q);
- cic->exit(cic);
- cic->release(cic);
+ icq->exit(icq);
+ icq->release(icq);
ioc_release_depth_dec(this_q);
}
@@ -131,10 +130,10 @@
return;
/*
- * Destroy @ioc. This is a bit messy because cic's are chained
+ * Destroy @ioc. This is a bit messy because icq's are chained
* from both ioc and queue, and ioc->lock nests inside queue_lock.
- * The inner ioc->lock should be held to walk our cic_list and then
- * for each cic the outer matching queue_lock should be grabbed.
+ * The inner ioc->lock should be held to walk our icq_list and then
+ * for each icq the outer matching queue_lock should be grabbed.
* ie. We need to do reverse-order double lock dancing.
*
* Another twist is that we are often called with one of the
@@ -153,11 +152,10 @@
spin_lock_irqsave_nested(&ioc->lock, flags,
ioc_release_depth(locked_q));
- while (!hlist_empty(&ioc->cic_list)) {
- struct cfq_io_context *cic = hlist_entry(ioc->cic_list.first,
- struct cfq_io_context,
- cic_list);
- struct request_queue *this_q = cic->q;
+ while (!hlist_empty(&ioc->icq_list)) {
+ struct io_cq *icq = hlist_entry(ioc->icq_list.first,
+ struct io_cq, ioc_node);
+ struct request_queue *this_q = icq->q;
if (this_q != last_q) {
if (last_q && last_q != locked_q)
@@ -170,8 +168,8 @@
continue;
}
ioc_release_depth_inc(this_q);
- cic->exit(cic);
- cic->release(cic);
+ icq->exit(icq);
+ icq->release(icq);
ioc_release_depth_dec(this_q);
}
@@ -180,8 +178,8 @@
spin_unlock_irqrestore(&ioc->lock, flags);
- /* if no cic's left, we're done; otherwise, kick release_work */
- if (hlist_empty(&ioc->cic_list))
+ /* if no icq is left, we're done; otherwise, kick release_work */
+ if (hlist_empty(&ioc->icq_list))
kmem_cache_free(iocontext_cachep, ioc);
else
schedule_work(&ioc->release_work);
@@ -219,8 +217,8 @@
atomic_long_set(&ioc->refcount, 1);
atomic_set(&ioc->nr_tasks, 1);
spin_lock_init(&ioc->lock);
- INIT_RADIX_TREE(&ioc->radix_root, GFP_ATOMIC | __GFP_HIGH);
- INIT_HLIST_HEAD(&ioc->cic_list);
+ INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC | __GFP_HIGH);
+ INIT_HLIST_HEAD(&ioc->icq_list);
INIT_WORK(&ioc->release_work, ioc_release_fn);
/* try to install, somebody might already have beaten us to it */
@@ -270,11 +268,11 @@
void ioc_set_changed(struct io_context *ioc, int which)
{
- struct cfq_io_context *cic;
+ struct io_cq *icq;
struct hlist_node *n;
- hlist_for_each_entry(cic, n, &ioc->cic_list, cic_list)
- set_bit(which, &cic->changed);
+ hlist_for_each_entry(icq, n, &ioc->icq_list, ioc_node)
+ set_bit(which, &icq->changed);
}
/**
@@ -282,8 +280,8 @@
* @ioc: io_context of interest
* @ioprio: new ioprio
*
- * @ioc's ioprio has changed to @ioprio. Set %CIC_IOPRIO_CHANGED for all
- * cic's. iosched is responsible for checking the bit and applying it on
+ * @ioc's ioprio has changed to @ioprio. Set %ICQ_IOPRIO_CHANGED for all
+ * icq's. iosched is responsible for checking the bit and applying it on
* request issue path.
*/
void ioc_ioprio_changed(struct io_context *ioc, int ioprio)
@@ -292,7 +290,7 @@
spin_lock_irqsave(&ioc->lock, flags);
ioc->ioprio = ioprio;
- ioc_set_changed(ioc, CIC_IOPRIO_CHANGED);
+ ioc_set_changed(ioc, ICQ_IOPRIO_CHANGED);
spin_unlock_irqrestore(&ioc->lock, flags);
}
@@ -300,7 +298,7 @@
* ioc_cgroup_changed - notify cgroup change
* @ioc: io_context of interest
*
- * @ioc's cgroup has changed. Set %CIC_CGROUP_CHANGED for all cic's.
+ * @ioc's cgroup has changed. Set %ICQ_CGROUP_CHANGED for all icq's.
* iosched is responsible for checking the bit and applying it on request
* issue path.
*/
@@ -309,7 +307,7 @@
unsigned long flags;
spin_lock_irqsave(&ioc->lock, flags);
- ioc_set_changed(ioc, CIC_CGROUP_CHANGED);
+ ioc_set_changed(ioc, ICQ_CGROUP_CHANGED);
spin_unlock_irqrestore(&ioc->lock, flags);
}