From 3793c65c13e4751c7a10f98198bae1758453eb0e Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@suse.de>
Date: Tue, 30 May 2006 21:11:04 +0200
Subject: [PATCH] [PATCH] cfq-iosched: fixup locking and ->queue_list list
management
- Drop cic from the list when seen as dead.
- Fixup the locking, just use a simple spinlock.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
block/cfq-iosched.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 2540dfaa3e385..11ce6aaf1bd02 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -33,7 +33,7 @@ static int cfq_slice_idle = HZ / 70;
#define CFQ_KEY_ASYNC (0)
-static DEFINE_RWLOCK(cfq_exit_lock);
+static DEFINE_SPINLOCK(cfq_exit_lock);
/*
* for the hash of cfqq inside the cfqd
@@ -1284,7 +1284,7 @@ static void cfq_exit_io_context(struct io_context *ioc)
/*
* put the reference this task is holding to the various queues
*/
- read_lock_irqsave(&cfq_exit_lock, flags);
+ spin_lock_irqsave(&cfq_exit_lock, flags);
n = rb_first(&ioc->cic_root);
while (n != NULL) {
@@ -1294,7 +1294,7 @@ static void cfq_exit_io_context(struct io_context *ioc)
n = rb_next(n);
}
- read_unlock_irqrestore(&cfq_exit_lock, flags);
+ spin_unlock_irqrestore(&cfq_exit_lock, flags);
}
static struct cfq_io_context *
@@ -1400,17 +1400,17 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
struct cfq_io_context *cic;
struct rb_node *n;
- write_lock(&cfq_exit_lock);
+ spin_lock(&cfq_exit_lock);
n = rb_first(&ioc->cic_root);
while (n != NULL) {
cic = rb_entry(n, struct cfq_io_context, rb_node);
-
+
changed_ioprio(cic);
n = rb_next(n);
}
- write_unlock(&cfq_exit_lock);
+ spin_unlock(&cfq_exit_lock);
return 0;
}
@@ -1475,9 +1475,10 @@ cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk,
static void
cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic)
{
- read_lock(&cfq_exit_lock);
+ spin_lock(&cfq_exit_lock);
rb_erase(&cic->rb_node, &ioc->cic_root);
- read_unlock(&cfq_exit_lock);
+ list_del_init(&cic->queue_list);
+ spin_unlock(&cfq_exit_lock);
kmem_cache_free(cfq_ioc_pool, cic);
atomic_dec(&ioc_count);
}
@@ -1545,11 +1546,11 @@ cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
BUG();
}
- read_lock(&cfq_exit_lock);
+ spin_lock(&cfq_exit_lock);
rb_link_node(&cic->rb_node, parent, p);
rb_insert_color(&cic->rb_node, &ioc->cic_root);
list_add(&cic->queue_list, &cfqd->cic_list);
- read_unlock(&cfq_exit_lock);
+ spin_unlock(&cfq_exit_lock);
}
/*
@@ -2187,7 +2188,7 @@ static void cfq_exit_queue(elevator_t *e)
cfq_shutdown_timer_wq(cfqd);
- write_lock(&cfq_exit_lock);
+ spin_lock(&cfq_exit_lock);
spin_lock_irq(q->queue_lock);
if (cfqd->active_queue)
@@ -2210,7 +2211,7 @@ static void cfq_exit_queue(elevator_t *e)
}
spin_unlock_irq(q->queue_lock);
- write_unlock(&cfq_exit_lock);
+ spin_unlock(&cfq_exit_lock);
cfq_shutdown_timer_wq(cfqd);
--
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