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

On Wed, 2017-02-15 at 05:29 -0800, Eric Dumazet wrote:

mlx4_eq_int() is a hard irq handler.

How a tasklet could run in the middle of it ?

A tasklet is a softirq handler.

Speaking of mlx4_eq_int() , 50% of cycles are spent on mb() (mfence)
in eq_set_ci()

I wonder why this very expensive mb() is required, right before exiting
the interrupt handler.