From: Neil Horman <[email protected]> Noticed that we can shuffle the code around in fcoe_percpu_receive_thread a bit and avoid taking the fcoe_rx_list lock twice per iteration. This should improve throughput somewhat. With this change we take the lock, and check for new frames in a single critical section. Only if the list is empty do we drop the lock and re-acquire it after being signaled to wake up.
Change Notes: v2) did some further cleanup on the patch by replacing the 2nd call of spin_lock/splice_init with a goto to the top of the outer loop. This allows me to change the inner while loop to an if conditional and remove the sencond check of kthread_should_stop. Based on suggestion from Vasu Dev. Signed-off-by: Neil Horman <[email protected]> Acked-by: Vasu Dev <[email protected]> Signed-off-by: Robert Love <[email protected]> --- drivers/scsi/fcoe/fcoe.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index fe30b1b..656ff65 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1851,23 +1851,25 @@ static int fcoe_percpu_receive_thread(void *arg) set_user_nice(current, -20); +retry: while (!kthread_should_stop()) { spin_lock_bh(&p->fcoe_rx_list.lock); skb_queue_splice_init(&p->fcoe_rx_list, &tmp); - spin_unlock_bh(&p->fcoe_rx_list.lock); - - while ((skb = __skb_dequeue(&tmp)) != NULL) - fcoe_recv_frame(skb); - spin_lock_bh(&p->fcoe_rx_list.lock); - if (!skb_queue_len(&p->fcoe_rx_list)) { + if (!skb_queue_len(&tmp)) { set_current_state(TASK_INTERRUPTIBLE); spin_unlock_bh(&p->fcoe_rx_list.lock); schedule(); set_current_state(TASK_RUNNING); - } else - spin_unlock_bh(&p->fcoe_rx_list.lock); + goto retry; + } + + spin_unlock_bh(&p->fcoe_rx_list.lock); + + while ((skb = __skb_dequeue(&tmp)) != NULL) + fcoe_recv_frame(skb); + } return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
