mlx4: do not fire tasklet unless necessary

All rx and rx netdev interrupts are handled by respectively
by mlx4_en_rx_irq() and mlx4_en_tx_irq() which simply schedule a NAPI.

But mlx4_eq_int() also fires a tasklet to service all items that were
queued via mlx4_add_cq_to_tasklet(), but this handler was not called
unless user cqe was handled.

This is very confusing, as "mpstat -I SCPU ..." show huge number of
tasklet invocations.

This patch saves this overhead, by carefully firing the tasklet directly
from mlx4_add_cq_to_tasklet(), removing four atomic operations per IRQ.

Signed-off-by: Eric Dumazet <[email protected]>
Cc: Tariq Toukan <[email protected]>
Cc: Saeed Mahameed <[email protected]>
Acked-by: Saeed Mahameed <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions