mlx4: change TX coalescing defaults

mlx4 currently uses a too high tx coalescing setting, deferring
TX completion interrupts by up to 128 us.

With the recent skb_orphan() removal in commit 8112ec3b872,
performance of a single TCP flow is capped to ~4 Gbps, unless
we increase tcp_limit_output_bytes.

I suggest using 16 us instead of 128 us, allowing a finer control.

Performance of a single TCP flow is restored to previous levels,
while keeping TCP small queues fully enabled with default sysctl.

This patch is also a BQL prereq.

Reported-by: Vimalkumar <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Yevgeny Petrilin <[email protected]>
Cc: Or Gerlitz <[email protected]>
Acked-by: Amir Vadai <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions