On 4/28/16 10:05 PM, Eric Dumazet wrote:

On Thu, 2016-04-28 at 21:43 -0700, Alexei Starovoitov wrote:

quoted

I don't understand the logic completely, but isn't it
safer to do 'goto wait_for_memory;' here if we happened
to hit this in the middle of the loop?

Well, the wait_for_memory pushes data, and could early return to user
space with short writes (non blocking IO). This would break things...

I see. Right. My only concern was about restarting the loop
and msg_data_left(), since it's really hard to follow iov_iter logic.