Re: [PATCH mptcp-net] mptcp: sched: check both backup in retrans

[Matthieu Baerts <matttbe@kernel.org>]

Hi Mat,

On 21/08/2024 03:24, Mat Martineau wrote:
> On Tue, 13 Aug 2024, Matthieu Baerts (NGI0) wrote:
> 
>> The 'mptcp_subflow_context' structure has two items related to the
>> backup flags:
>>
>> - 'backup': the subflow has been marked as backup by the other peer
>>
>> - 'request_bkup': the backup flag has been set by the host
>>
>> Looking only at the 'backup' flag can make sense in some cases, but it
>> is not the behaviour of the default packet scheduler when selecting
>> paths.
>>
>> As explained in the commit b6a66e521a20 ("mptcp: sched: check both
>> directions for backup"), the packet scheduler should look at both flags,
>> because that was the behaviour from the beginning: the 'backup' flag was
>> set by accident instead of the 'request_bkup' one. Now that the latter
>> has been fixed, get_retrans() needs to be adapted as well.
>>
>> Fixes: 3b1d6210a957 ("mptcp: implement and use MPTCP-level
>> retransmission")
> 
> I think this should have:
> 
> Fixes: b6a66e521a20 ("mptcp: sched: check both directions for backup")

Good idea, I switched to that one when applying the patch.

> and a Cc: stable ?

Yes, I add them when sending patches to netdev.

> Reviewed-by: Mat Martineau <martineau@kernel.org>

New patches for t/upstream-net and t/upstream:
- 353d48321ce0: mptcp: sched: check both backup in retrans
- Results: c025238d573a..76f6fba9ef6b (export-net)
- Results: a2eeb886f736..80d8c6b850fb (export)

Tests are now in progress:

- export-net:
https://github.com/multipath-tcp/mptcp_net-next/commit/2e798b8d759eb6a9a1ee14544e625cae61a9cad3/checks
- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/91a502295edf01f2c23e9f11edad1d7db908d21f/checks

Cheers,
Matt
-- 
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