Re: [PATCH net-next 2/3] mlx4_en: moderate frequency of TX completions

From: Ben Hutchings <redacted>
Date: Thu, 23 Feb 2012 21:13:56 +0000

On Thu, 2012-02-23 at 14:44 -0500, David Miller wrote:

quoted

From: Yevgeny Petrilin <redacted>
Date: Thu, 23 Feb 2012 15:34:27 +0200

quoted

No need to ask for completion for every packet being sent.
So the method is to ask for a completion every 16 packets,
or when the queue is about to be full.

Signed-off-by: Yevgeny Petrilin <redacted>

You absolutely cannot do this, you must signal completion and free up
TX queue packets in a finite amount of time.

Really, sfc has been doing this forever.

You have to stop, because otherwise sockets can hang since those
packets can hold a reference to the socket so they must be
released in a finite amount of time regardless of network
traffic.