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authorEd Cashin <ecashin@coraid.com>2012-10-04 17:16:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-06 03:05:25 +0900
commiteb086ec59667df5b07d58176e21a5f523ead1d66 (patch)
tree85c0fa90b4791659f128518115ca0df4ece88586
parent69cf2d85de773d998798e47e3335b85e5645d157 (diff)
aoe: use a kernel thread for transmissions
The dev_queue_xmit function needs to have interrupts enabled, so the most simple way to get the locking right but still fulfill that requirement is to use a process that can call dev_queue_xmit serially over queued transmissions. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/block/aoe/aoe.h2
-rw-r--r--drivers/block/aoe/aoecmd.c4
-rw-r--r--drivers/block/aoe/aoenet.c37
3 files changed, 40 insertions, 3 deletions
diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index 8c4f6d942e0..d0087de1780 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -210,6 +210,8 @@ struct sk_buff *aoecmd_ata_id(struct aoedev *);
void aoe_freetframe(struct frame *);
void aoe_flush_iocq(void);
void aoe_end_request(struct aoedev *, struct request *, int);
+int aoe_ktstart(struct ktstate *k);
+void aoe_ktstop(struct ktstate *k);
int aoedev_init(void);
void aoedev_exit(void);
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 5928a08c1f3..a1c5e8aa08c 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -1110,14 +1110,14 @@ kthread(void *vp)
return 0;
}
-static void
+void
aoe_ktstop(struct ktstate *k)
{
kthread_stop(k->task);
wait_for_completion(&k->rendez);
}
-static int
+int
aoe_ktstart(struct ktstate *k)
{
struct task_struct *task;
diff --git a/drivers/block/aoe/aoenet.c b/drivers/block/aoe/aoenet.c
index 000eff2b53a..5f43710601a 100644
--- a/drivers/block/aoe/aoenet.c
+++ b/drivers/block/aoe/aoenet.c
@@ -33,6 +33,9 @@ static char aoe_iflist[IFLISTSZ];
module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=\"dev1 [dev2 ...]\"");
+static wait_queue_head_t txwq;
+static struct ktstate kts;
+
#ifndef MODULE
static int __init aoe_iflist_setup(char *str)
{
@@ -44,6 +47,23 @@ static int __init aoe_iflist_setup(char *str)
__setup("aoe_iflist=", aoe_iflist_setup);
#endif
+static spinlock_t txlock;
+static struct sk_buff_head skbtxq;
+
+/* enters with txlock held */
+static int
+tx(void)
+{
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&skbtxq))) {
+ spin_unlock_irq(&txlock);
+ dev_queue_xmit(skb);
+ spin_lock_irq(&txlock);
+ }
+ return 0;
+}
+
int
is_aoe_netif(struct net_device *ifp)
{
@@ -88,10 +108,14 @@ void
aoenet_xmit(struct sk_buff_head *queue)
{
struct sk_buff *skb, *tmp;
+ ulong flags;
skb_queue_walk_safe(queue, skb, tmp) {
__skb_unlink(skb, queue);
- dev_queue_xmit(skb);
+ spin_lock_irqsave(&txlock, flags);
+ skb_queue_tail(&skbtxq, skb);
+ spin_unlock_irqrestore(&txlock, flags);
+ wake_up(&txwq);
}
}
@@ -169,6 +193,15 @@ static struct packet_type aoe_pt __read_mostly = {
int __init
aoenet_init(void)
{
+ skb_queue_head_init(&skbtxq);
+ init_waitqueue_head(&txwq);
+ spin_lock_init(&txlock);
+ kts.lock = &txlock;
+ kts.fn = tx;
+ kts.waitq = &txwq;
+ kts.name = "aoe_tx";
+ if (aoe_ktstart(&kts))
+ return -EAGAIN;
dev_add_pack(&aoe_pt);
return 0;
}
@@ -176,6 +209,8 @@ aoenet_init(void)
void
aoenet_exit(void)
{
+ aoe_ktstop(&kts);
+ skb_queue_purge(&skbtxq);
dev_remove_pack(&aoe_pt);
}