Re: [PATCH mptcp-next 1/4] mptcp: update __mptcp_push_pending

[Geliang Tang <geliang.tang@suse.com>]

On Wed, Sep 28, 2022 at 01:02:07PM +0200, Paolo Abeni wrote:
> On Wed, 2022-09-28 at 17:48 +0800, Geliang Tang wrote:
> > To support redundant package schedulers more easily, this patch moves the
> > packet scheduler out of the dfrags loop in __mptcp_push_pending(), invoke
> > mptcp_sched_get_send() only once. 
> 
> I fear the above will make cause hitting HoL blocking [more]
> frequently/easily. I'm not sure if the simult_flows.sh self test will
> catch that, but you should see a measurably worse running time for such
> test - in non debug build, as the average of multiple runs.

Yes, simult_flows.sh self test failed in my tests. I guess this problem
also exists in "BPF redundant scheduler" v12, because it also uses the
same logic in __mptcp_push_pending(), move the packet scheduler out of
the dfrags loop.

> 
> I'm sorry, I can't see a feasible way out here :(
> 
> /P
>