fcoe: convert to kworker
The driver creates its own per-CPU threads which are updated based on
CPU hotplug events. It is also possible to use kworkers and remove some
of the kthread infrastrucure.
The code checked ->thread to decide if there is an active per-CPU
thread. By using the kworker infrastructure this is no longer
possible (or required). The thread pointer is saved in `kthread' instead
of `thread' so anything trying to use thread is caught by the
compiler. Currently only the bnx2fc driver is using struct fcoe_percpu_s
and the kthread member.
After a CPU went offline, we may still enqueue items on the "offline"
CPU. This isn't much of a problem. The work will be done on a random
CPU. The allocated crc_eof_page page won't be cleaned up. It is probably
expected that the CPU comes up at some point so it should not be a
problem. The crc_eof_page memory is released of course once the module
is removed.
This patch was only compile-tested due to -ENODEV.
Cc: Vasu Dev <vasu.dev@intel.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: fcoe-devel@open-fcoe.org
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
index a188199..d6800af 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
@@ -486,7 +486,7 @@
__skb_queue_tail(&bg->fcoe_rx_list, skb);
if (bg->fcoe_rx_list.qlen == 1)
- wake_up_process(bg->thread);
+ wake_up_process(bg->kthread);
spin_unlock(&bg->fcoe_rx_list.lock);
@@ -2715,7 +2715,7 @@
}
wake_up_process(l2_thread);
spin_lock_bh(&bg->fcoe_rx_list.lock);
- bg->thread = l2_thread;
+ bg->kthread = l2_thread;
spin_unlock_bh(&bg->fcoe_rx_list.lock);
for_each_possible_cpu(cpu) {
@@ -2788,8 +2788,8 @@
/* Destroy global thread */
bg = &bnx2fc_global;
spin_lock_bh(&bg->fcoe_rx_list.lock);
- l2_thread = bg->thread;
- bg->thread = NULL;
+ l2_thread = bg->kthread;
+ bg->kthread = NULL;
while ((skb = __skb_dequeue(&bg->fcoe_rx_list)) != NULL)
kfree_skb(skb);