[SCSI] lpfc 8.2.7 : Rework the worker thread
Rework of the worker thread to make it more efficient.
Make a finer-grain notfication of pending work so less time is
spent checking conditions. Also made other general cleanups.
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index f3dc19d..ba4873c 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -153,11 +153,11 @@
* count until this queued work is done
*/
evtp->evt_arg1 = lpfc_nlp_get(ndlp);
- evtp->evt = LPFC_EVT_DEV_LOSS;
- list_add_tail(&evtp->evt_listp, &phba->work_list);
- if (phba->work_wait)
- wake_up(phba->work_wait);
-
+ if (evtp->evt_arg1) {
+ evtp->evt = LPFC_EVT_DEV_LOSS;
+ list_add_tail(&evtp->evt_listp, &phba->work_list);
+ lpfc_worker_wake_up(phba);
+ }
spin_unlock_irq(&phba->hbalock);
return;
@@ -276,14 +276,6 @@
lpfc_disc_state_machine(vport, ndlp, NULL, NLP_EVT_DEVICE_RM);
}
-
-void
-lpfc_worker_wake_up(struct lpfc_hba *phba)
-{
- wake_up(phba->work_wait);
- return;
-}
-
static void
lpfc_work_list_done(struct lpfc_hba *phba)
{
@@ -429,6 +421,8 @@
|| (pring->flag & LPFC_DEFERRED_RING_EVENT)) {
if (pring->flag & LPFC_STOP_IOCB_EVENT) {
pring->flag |= LPFC_DEFERRED_RING_EVENT;
+ /* Set the lpfc data pending flag */
+ set_bit(LPFC_DATA_READY, &phba->data_flags);
} else {
pring->flag &= ~LPFC_DEFERRED_RING_EVENT;
lpfc_sli_handle_slow_ring_event(phba, pring,
@@ -459,69 +453,29 @@
lpfc_work_list_done(phba);
}
-static int
-check_work_wait_done(struct lpfc_hba *phba)
-{
- struct lpfc_vport *vport;
- struct lpfc_sli_ring *pring = &phba->sli.ring[LPFC_ELS_RING];
- int rc = 0;
-
- spin_lock_irq(&phba->hbalock);
- list_for_each_entry(vport, &phba->port_list, listentry) {
- if (vport->work_port_events) {
- rc = 1;
- break;
- }
- }
- if (rc || phba->work_ha || (!list_empty(&phba->work_list)) ||
- kthread_should_stop() || pring->flag & LPFC_DEFERRED_RING_EVENT) {
- rc = 1;
- phba->work_found++;
- } else
- phba->work_found = 0;
- spin_unlock_irq(&phba->hbalock);
- return rc;
-}
-
-
int
lpfc_do_work(void *p)
{
struct lpfc_hba *phba = p;
int rc;
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(work_waitq);
set_user_nice(current, -20);
- phba->work_wait = &work_waitq;
- phba->work_found = 0;
+ phba->data_flags = 0;
while (1) {
-
- rc = wait_event_interruptible(work_waitq,
- check_work_wait_done(phba));
-
+ /* wait and check worker queue activities */
+ rc = wait_event_interruptible(phba->work_waitq,
+ (test_and_clear_bit(LPFC_DATA_READY,
+ &phba->data_flags)
+ || kthread_should_stop()));
BUG_ON(rc);
if (kthread_should_stop())
break;
+ /* Attend pending lpfc data processing */
lpfc_work_done(phba);
-
- /* If there is alot of slow ring work, like during link up
- * check_work_wait_done() may cause this thread to not give
- * up the CPU for very long periods of time. This may cause
- * soft lockups or other problems. To avoid these situations
- * give up the CPU here after LPFC_MAX_WORKER_ITERATION
- * consecutive iterations.
- */
- if (phba->work_found >= LPFC_MAX_WORKER_ITERATION) {
- phba->work_found = 0;
- schedule();
- }
}
- spin_lock_irq(&phba->hbalock);
- phba->work_wait = NULL;
- spin_unlock_irq(&phba->hbalock);
return 0;
}
@@ -551,10 +505,10 @@
spin_lock_irqsave(&phba->hbalock, flags);
list_add_tail(&evtp->evt_listp, &phba->work_list);
- if (phba->work_wait)
- lpfc_worker_wake_up(phba);
spin_unlock_irqrestore(&phba->hbalock, flags);
+ lpfc_worker_wake_up(phba);
+
return 1;
}
@@ -2636,21 +2590,20 @@
{
struct lpfc_vport *vport = (struct lpfc_vport *) ptr;
struct lpfc_hba *phba = vport->phba;
+ uint32_t tmo_posted;
unsigned long flags = 0;
if (unlikely(!phba))
return;
- if ((vport->work_port_events & WORKER_DISC_TMO) == 0) {
- spin_lock_irqsave(&vport->work_port_lock, flags);
+ spin_lock_irqsave(&vport->work_port_lock, flags);
+ tmo_posted = vport->work_port_events & WORKER_DISC_TMO;
+ if (!tmo_posted)
vport->work_port_events |= WORKER_DISC_TMO;
- spin_unlock_irqrestore(&vport->work_port_lock, flags);
+ spin_unlock_irqrestore(&vport->work_port_lock, flags);
- spin_lock_irqsave(&phba->hbalock, flags);
- if (phba->work_wait)
- lpfc_worker_wake_up(phba);
- spin_unlock_irqrestore(&phba->hbalock, flags);
- }
+ if (!tmo_posted)
+ lpfc_worker_wake_up(phba);
return;
}