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authorTejun Heo <tj@kernel.org>2012-02-15 09:45:49 +0100
committerJens Axboe <axboe@kernel.dk>2012-02-15 09:45:49 +0100
commitd705ae6b133f9f6a8beee617b1224b6a5c99c5da (patch)
treeb1a0b09ae01f8385e66c021c338106b88e8d23f8 /block
parent7ada1dd62804ca9ce1cb8666c6e563cd92fa50c1 (diff)
downloadlinux-linaro-stable-d705ae6b133f9f6a8beee617b1224b6a5c99c5da.tar.gz
block: replace icq->changed with icq->flags
icq->changed was used for ICQ_*_CHANGED bits. Rename it to flags and access it under ioc->lock instead of using atomic bitops. ioc_get_changed() is added so that the changed part can be fetched and cleared as before. icq->flags will be used to carry other flags. Signed-off-by: Tejun Heo <tj@kernel.org> Tested-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-ioc.c30
-rw-r--r--block/cfq-iosched.c12
2 files changed, 32 insertions, 10 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 8b782a63c297..811879c752e4 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -363,13 +363,13 @@ struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask)
return icq;
}
-void ioc_set_changed(struct io_context *ioc, int which)
+void ioc_set_icq_flags(struct io_context *ioc, unsigned int flags)
{
struct io_cq *icq;
struct hlist_node *n;
hlist_for_each_entry(icq, n, &ioc->icq_list, ioc_node)
- set_bit(which, &icq->changed);
+ icq->flags |= flags;
}
/**
@@ -387,7 +387,7 @@ void ioc_ioprio_changed(struct io_context *ioc, int ioprio)
spin_lock_irqsave(&ioc->lock, flags);
ioc->ioprio = ioprio;
- ioc_set_changed(ioc, ICQ_IOPRIO_CHANGED);
+ ioc_set_icq_flags(ioc, ICQ_IOPRIO_CHANGED);
spin_unlock_irqrestore(&ioc->lock, flags);
}
@@ -404,11 +404,33 @@ void ioc_cgroup_changed(struct io_context *ioc)
unsigned long flags;
spin_lock_irqsave(&ioc->lock, flags);
- ioc_set_changed(ioc, ICQ_CGROUP_CHANGED);
+ ioc_set_icq_flags(ioc, ICQ_CGROUP_CHANGED);
spin_unlock_irqrestore(&ioc->lock, flags);
}
EXPORT_SYMBOL(ioc_cgroup_changed);
+/**
+ * icq_get_changed - fetch and clear icq changed mask
+ * @icq: icq of interest
+ *
+ * Fetch and clear ICQ_*_CHANGED bits from @icq. Grabs and releases
+ * @icq->ioc->lock.
+ */
+unsigned icq_get_changed(struct io_cq *icq)
+{
+ unsigned int changed = 0;
+ unsigned long flags;
+
+ if (unlikely(icq->flags & ICQ_CHANGED_MASK)) {
+ spin_lock_irqsave(&icq->ioc->lock, flags);
+ changed = icq->flags & ICQ_CHANGED_MASK;
+ icq->flags &= ~ICQ_CHANGED_MASK;
+ spin_unlock_irqrestore(&icq->ioc->lock, flags);
+ }
+ return changed;
+}
+EXPORT_SYMBOL(icq_get_changed);
+
static int __init blk_ioc_init(void)
{
iocontext_cachep = kmem_cache_create("blkdev_ioc",
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index d0ba50533668..457295253566 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3470,20 +3470,20 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
const int rw = rq_data_dir(rq);
const bool is_sync = rq_is_sync(rq);
struct cfq_queue *cfqq;
+ unsigned int changed;
might_sleep_if(gfp_mask & __GFP_WAIT);
spin_lock_irq(q->queue_lock);
/* handle changed notifications */
- if (unlikely(cic->icq.changed)) {
- if (test_and_clear_bit(ICQ_IOPRIO_CHANGED, &cic->icq.changed))
- changed_ioprio(cic);
+ changed = icq_get_changed(&cic->icq);
+ if (unlikely(changed & ICQ_IOPRIO_CHANGED))
+ changed_ioprio(cic);
#ifdef CONFIG_CFQ_GROUP_IOSCHED
- if (test_and_clear_bit(ICQ_CGROUP_CHANGED, &cic->icq.changed))
- changed_cgroup(cic);
+ if (unlikely(changed & ICQ_CGROUP_CHANGED))
+ changed_cgroup(cic);
#endif
- }
new_queue:
cfqq = cic_to_cfqq(cic, is_sync);