Re: [PATCH 6.11/6.12] net_sched: sch_fq: don't follow the fast path if Tx is behind now

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 122aba8c80618eca904490b1733af27fb8f07528


Status in newer kernel trees:
6.12.y | Not found

Note: The patch differs from the upstream commit:
---
1:  122aba8c80618 ! 1:  14d9d00a6b68f net_sched: sch_fq: don't follow the fast path if Tx is behind now
    @@ Metadata
      ## Commit message ##
         net_sched: sch_fq: don't follow the fast path if Tx is behind now
     
    +    [ Upstream commit 122aba8c80618eca904490b1733af27fb8f07528 ]
    +
         Recent kernels cause a lot of TCP retransmissions
     
         [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
    @@ Commit message
         Reviewed-by: Eric Dumazet <edumazet@google.com>
         Link: https://patch.msgid.link/20241124022148.3126719-1-kuba@kernel.org
         Signed-off-by: Paolo Abeni <pabeni@redhat.com>
    +    [stable: drop the offload horizon, it's not supported / 0]
    +    Signed-off-by: Jakub Kicinski <kuba@kernel.org>
     
      ## net/sched/sch_fq.c ##
     @@ net/sched/sch_fq.c: static bool fq_fastpath_check(const struct Qdisc *sch, struct sk_buff *skb,
    @@ net/sched/sch_fq.c: static bool fq_fastpath_check(const struct Qdisc *sch, struc
     +		/* Ordering invariants fall apart if some delayed flows
     +		 * are ready but we haven't serviced them, yet.
     +		 */
    -+		if (q->time_next_delayed_flow <= now + q->offload_horizon)
    ++		if (q->time_next_delayed_flow <= now)
     +			return false;
      	}
      
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.12.y       |  Success    |  Success   |
| stable/linux-6.11.y       |  Success    |  Success   |