Re: TCPBacklogDrops during aggressive bursts of traffic

Kieran Mansley
2012-05-18T15:45:56Z

On Thu, 2012-05-17 at 18:37 +0200, Eric Dumazet wrote:
>
> Hmm, I was not suggesting running production servers with this
> setting, only do an experiment.

OK. I've found a more reliable way to reproduce it (use MSG_WAITALL to
make the recv call wait till the socket buffer will be more full) and
tried with the tcp_adv_win_scale to -2. It's hard to make any confident
assertions about the impact of it, but if it does change the behaviour
it is a small change. There are certainly still plenty of drops with
that setting.

> With net-next and tcp coalescing, I no longer have TCPBacklogDrops /
> collapses, but I dont have sfc card/driver.

I'll try that.

Kieran