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[SCSI] bnx2fc: IO completion not processed due to missed wakeup 

Driver does not detect a new CQE (completion queue entry) if a thread receives
the wakup when it is in TASK_RUNNING state. Fix is to set the state to
TASK_INTERRUPTIBLE while holding the fp_work_lock.

Also, Use __set_current_task() since it is now set inside a spinlock with
synchronization.

Two other related optimizations:

1.  After we exit the while (!kthread_should_stop()) loop, use
__set_current_state() since synchronization is no longer needed.

2.  Remove set_current_state(TASK_RUNNING) after schedule() since it
should always be TASK_RUNNING after schedule().

Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This commit is contained in:
Bhanu Gollapudi 2011-03-21 18:51:13 -07:00 committed by James Bottomley
parent 2dcb0a6104
commit fee787129d
1 changed files with 4 additions and 6 deletions
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10
drivers/scsi/bnx2fc/bnx2fc_fcoe.c
View File

@ -437,17 +437,16 @@ static int bnx2fc_l2_rcv_thread(void *arg)
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
schedule();
set_current_state(TASK_RUNNING);
spin_lock_bh(&bg->fcoe_rx_list.lock);
while ((skb = __skb_dequeue(&bg->fcoe_rx_list)) != NULL) {
spin_unlock_bh(&bg->fcoe_rx_list.lock);
bnx2fc_recv_frame(skb);
spin_lock_bh(&bg->fcoe_rx_list.lock);
}
__set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_bh(&bg->fcoe_rx_list.lock);
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
__set_current_state(TASK_RUNNING);
return 0;
}
@ -569,7 +568,6 @@ int bnx2fc_percpu_io_thread(void *arg)
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
schedule();
set_current_state(TASK_RUNNING);
spin_lock_bh(&p->fp_work_lock);
while (!list_empty(&p->work_list)) {
list_splice_init(&p->work_list, &work_list);
@ -583,10 +581,10 @@ int bnx2fc_percpu_io_thread(void *arg)
spin_lock_bh(&p->fp_work_lock);
}
__set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_bh(&p->fp_work_lock);
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
__set_current_state(TASK_RUNNING);
return 0;
}