FQ-PIE runs an independent PIE controller per flow but exposes no
per-flow statistics. This series wires up fq_pie_class_ops to expose
per-flow AQM state (prob, delay, deficit, avg_dq_rate) via
'tc -s class show', following a similar pattern as FQ-CoDel.

This patch series is accompanied by a companion iproute2 patch series that
can be found at:
https://lore.kernel.org/netdev/20260902040221.83734-1-hemendranaik@gmail.com/

---
Changelog:

v6:
- Address Sashiko review comments:
  - Revert the fq_pie flows range to [1..65536]. 
  - Also drop the accompanying selftest 83be change.
  - Compute the per-flow delay with div_u64() on the full 64-bit
    nanosecond value.
  - Widen avg_dq_rate to u64 before scaling it by PSCHED_TICKS_PER_SEC.
  - Document the 36 to 64 byte xstats growth in the patch 1 commit message.
  - Fix selftest 83c0. The ping payload exceeded the TBF burst so no
    packet ever reached fq_pie, and the missing -W left the run waiting
    out ping's default timeout.

v5: https://lore.kernel.org/netdev/20260902035231.81866-1-hemendranaik@gmail.com/
- Addressed Sashiko review comments:
 - Omitted .tcf_block / .bind_tcf / .unbind_tcf from cl_ops (statistics
   only being exported; filter attach to fq_pie is now disabled).
 - Dropped empty tc_fq_pie_xqd_stats placeholder; class_stats is a direct
   struct member.
 - Limited flows to [1..65535] so per-flow class handles fit in a 16-bit
   TC minor.
 - Rewrote selftest 83c0 with TBF + fq_pie, ping traffic, and
   matchCount 1 on per-flow stats output.
 - Updated selftest 83be for the new flows limit.
 - Dropped the tools/include UAPI mirror changes from patch 3/3.

v4: https://lore.kernel.org/netdev/20260727164056.106203-1-hemendranaik@gmail.com/
- Fixed unaligned commit message; moved typo fixes to another patch.

v3: https://lore.kernel.org/netdev/20260630183702.170798-1-hemendranaik@gmail.com/
- No changes since v2.
- Resent after the previous submission was deferred due to the
  net-next tree closing during review.
- Updated corresponding iproute2 patch in response to review comments;
  kernel patches unchanged.

v2: https://lore.kernel.org/netdev/20260614125000.6058-1-hemendranaik@gmail.com/
- Addressed ABI backward compatibility issue for tc_fq_pie_xstats.

v1: https://lore.kernel.org/netdev/20260531125314.22492-1-hemendranaik@gmail.com/
- Initial submission

Hemendra M. Naik (3):
  net/sched: sch_fq_pie: add per-flow statistics via class ops
  selftests: tc-testing: add fq_pie per-flow class stats test
  net/sched: pie: correct tc_pie_xstats field documentation

 include/uapi/linux/pkt_sched.h                | 20 ++++-
 net/sched/sch_fq_pie.c                        | 86 ++++++++++++++++++-
 .../tc-testing/tc-tests/qdiscs/fq_pie.json    | 27 ++++++
 3 files changed, 130 insertions(+), 3 deletions(-)

-- 
2.34.1

On Fri, 18 Sep 2026 02:12:22 +0530 Hemendra M. Naik wrote:
> This patch series is accompanied by a companion iproute2 patch series that
> can be found at:
> https://lore.kernel.org/netdev/20260902040221.83734-1-hemendranaik@gmail.com/

Does not apply any more. Also can you put it on a branch on github to
make it easier to pull please ? 

Please rebase and repost both the kernel and the iproute2.

Hi Jakub,

We've posted the new patches for kernel (v7) and iproute2 (v6) 
after rebasing.

The mailing list threads can be tracked here:
- Kernel v7: https://lore.kernel.org/netdev/20260919060125.38063-1-hemendranaik@gmail.com/
- iproute2 v6: https://lore.kernel.org/netdev/20260919061254.39678-1-hemendranaik@gmail.com/

As requested, we have also posted the latest 
patches on GitHub which can be found here:

- https://github.com/H-N41K/linux-net-next/tree/fq_pie_class_stats/
- https://github.com/H-N41K/iproute2-next/tree/fq_pie_class_stats/

Thanks,
Hemendra

On Sat, 19 Sep 2026 11:56:13 +0530 Hemendra M. Naik wrote:
> - https://github.com/H-N41K/iproute2-next/tree/fq_pie_class_stats/

Thanks, please vendor in the headers on this branch so we can add 
it in the CI and it will just build as is. LMK when ready.

Hi Jakub,

We have vendored the temporary UAPI header changes into the GitHub 
development branch (https://github.com/H-N41K/iproute2-next/tree/fq_pie_class_stats/)
as requested, so it should now build standalone in your CI pipeline. 

Please note that this header sync commit is not present in the official 
iproute2 patch submitted to the mailing list 
(https://lore.kernel.org/netdev/20260922211139.38570-1-hemendranaik@gmail.com/). 
It was added to the GitHub branch strictly for validation and testing purposes.

Regards,
Hemendra

On Wed, 23 Sep 2026 09:31:36 +0530 Hemendra M. Naik wrote:
> Hi Jakub,
> 
> We have vendored the temporary UAPI header changes into the GitHub 
> development branch (https://github.com/H-N41K/iproute2-next/tree/fq_pie_class_stats/)
> as requested, so it should now build standalone in your CI pipeline. 
> 
> Please note that this header sync commit is not present in the official 
> iproute2 patch submitted to the mailing list 
> (https://lore.kernel.org/netdev/20260922211139.38570-1-hemendranaik@gmail.com/). 
> It was added to the GitHub branch strictly for validation and testing purposes.

Thanks!

Victor, could you pull this into tdc as well?

On Wed, Sep 23, 2026 at 11:53 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 23 Sep 2026 09:31:36 +0530 Hemendra M. Naik wrote:
> > Hi Jakub,
> >
> > We have vendored the temporary UAPI header changes into the GitHub
> > development branch (https://github.com/H-N41K/iproute2-next/tree/fq_pie_class_stats/)
> > as requested, so it should now build standalone in your CI pipeline.
> >
> > Please note that this header sync commit is not present in the official
> > iproute2 patch submitted to the mailing list
> > (https://lore.kernel.org/netdev/20260922211139.38570-1-hemendranaik@gmail.com/).
> > It was added to the GitHub branch strictly for validation and testing purposes.
>
> Thanks!
>
> Victor, could you pull this into tdc as well?

Done, it's in tdc.

cheers,
Victor

On Thu, 24 Sep 2026 08:35:34 -0300 Victor Nogueira wrote:
> On Wed, Sep 23, 2026 at 11:53 PM Jakub Kicinski <kuba@kernel.org> wrote:
> >
> > On Wed, 23 Sep 2026 09:31:36 +0530 Hemendra M. Naik wrote:  
> > > Hi Jakub,
> > >
> > > We have vendored the temporary UAPI header changes into the GitHub
> > > development branch (https://github.com/H-N41K/iproute2-next/tree/fq_pie_class_stats/)
> > > as requested, so it should now build standalone in your CI pipeline.
> > >
> > > Please note that this header sync commit is not present in the official
> > > iproute2 patch submitted to the mailing list
> > > (https://lore.kernel.org/netdev/20260922211139.38570-1-hemendranaik@gmail.com/).
> > > It was added to the GitHub branch strictly for validation and testing purposes.  
> >
> > Thanks!
> >
> > Victor, could you pull this into tdc as well?  
> 
> Done, it's in tdc.

Thanks!

https://lore.kernel.org/all/20260922205924.32173-3-hemendranaik@gmail.com/

will return in net-next-2026-09-24--18-00