Re: [PATCH net-next] mlx4: do not fire tasklet unless necessary

[Eric Dumazet]

On Thu, 2017-02-16 at 07:30 -0800, Eric Dumazet wrote:
> On Thu, 2017-02-16 at 14:38 +0200, Saeed Mahameed wrote:
> 
> > Acked-by: Saeed Mahameed <sae...@mellanox.com>
> 
> Thanks for reviewing this Saeed !

Note that mlx4_add_cq_to_tasklet() is called from hard irq context, so
we could replace the spin_lock_irqsave() by spin_lock()

Not that I care, but you might be interested ;)

Thanks.

diff --git a/drivers/net/ethernet/mellanox/mlx4/cq.c 
b/drivers/net/ethernet/mellanox/mlx4/cq.c
index 
fa6d2354a0e910ee160863e3cbe21a512d77bf03..9dcac3a367425f2804e933842698c66685baf626
 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cq.c
@@ -79,13 +79,13 @@ void mlx4_cq_tasklet_cb(unsigned long data)
                tasklet_schedule(&ctx->task);
 }
 
+/* Called from hard irq handler */
 static void mlx4_add_cq_to_tasklet(struct mlx4_cq *cq)
 {
        struct mlx4_eq_tasklet *tasklet_ctx = cq->tasklet_ctx.priv;
-       unsigned long flags;
        bool kick;
 
-       spin_lock_irqsave(&tasklet_ctx->lock, flags);
+       spin_lock(&tasklet_ctx->lock);
        /* When migrating CQs between EQs will be implemented, please note
         * that you need to sync this point. It is possible that
         * while migrating a CQ, completions on the old EQs could
@@ -98,7 +98,7 @@ static void mlx4_add_cq_to_tasklet(struct mlx4_cq *cq)
                if (kick)
                        tasklet_schedule(&tasklet_ctx->task);
        }
-       spin_unlock_irqrestore(&tasklet_ctx->lock, flags);
+       spin_unlock(&tasklet_ctx->lock);
 }
 
 void mlx4_cq_completion(struct mlx4_dev *dev, u32 cqn)