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  1. 20 12月, 2019 22 次提交
  3. 19 12月, 2019 18 次提交
    • J
      net: stmmac: tc: Fix TAPRIO division operation · a1ec57c0
      由 Jose Abreu 提交于 
      For ARCHs that don't support 64 bits division we need to use the
helpers.

Fixes: b60189e0 ("net: stmmac: Integrate EST with TAPRIO scheduler API")
Signed-off-by: NJose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a1ec57c0
    • D
      Merge branch 'ETS-qdisc' · 6bff0017
      由 David S. Miller 提交于 
      Petr Machata says:

====================
Add a new Qdisc, ETS

The IEEE standard 802.1Qaz (and 802.1Q-2014) specifies four principal
transmission selection algorithms: strict priority, credit-based shaper,
ETS (bandwidth sharing), and vendor-specific. All these have their
corresponding knobs in DCB. But DCB does not have interfaces to configure
RED and ECN, unlike Qdiscs.

In the Qdisc land, strict priority is implemented by PRIO. Credit-based
transmission selection algorithm can then be modeled by having e.g. TBF or
CBS Qdisc below some of the PRIO bands. ETS would then be modeled by
placing a DRR Qdisc under the last PRIO band.

The problem with this approach is that DRR on its own, as well as the
combination of PRIO and DRR, are tricky to configure and tricky to offload
to 802.1Qaz-compliant hardware. This is due to several reasons:

- As any classful Qdisc, DRR supports adding classifiers to decide in which
  class to enqueue packets. Unlike PRIO, there's however no fallback in the
  form of priomap. A way to achieve classification based on packet priority
  is e.g. like this:

    # tc filter add dev swp1 root handle 1: \
		basic match 'meta(priority eq 0)' flowid 1:10

  Expressing the priomap in this manner however forces drivers to deep dive
  into the classifier block to parse the individual rules.

  A possible solution would be to extend the classes with a "defmap" a la
  split / defmap mechanism of CBQ, and introduce this as a last resort
  classification. However, unlike priomap, this doesn't have the guarantee
  of covering all priorities. Traffic whose priority is not covered is
  dropped by DRR as unclassified. But ASICs tend to implement dropping in
  the ACL block, not in scheduling pipelines. The need to treat these
  configurations correctly (if only to decide to not offload at all)
  complicates a driver.

  It's not clear how to retrofit priomap with all its benefits to DRR
  without changing it beyond recognition.

- The interplay between PRIO and DRR is also causing problems. 802.1Qaz has
  all ETS TCs as a last resort. Switch ASICs that support ETS at all are
  likely to handle ETS traffic this way as well. However, the Linux model
  is more generic, allowing the DRR block in any band. Drivers would need
  to be careful to handle this case correctly, otherwise the offloaded
  model might not match the slow-path one.

  In a similar vein, PRIO and DRR need to agree on the list of priorities
  assigned to DRR. This is doubly problematic--the user needs to take care
  to keep the two in sync, and the driver needs to watch for any holes in
  DRR coverage and treat the traffic correctly, as discussed above.

  Note that at the time that DRR Qdisc is added, it has no classes, and
  thus any priorities assigned to that PRIO band are not covered. Thus this
  case is surprisingly rather common, and needs to be handled gracefully by
  the driver.

- Similarly due to DRR flexibility, when a Qdisc (such as RED) is attached
  below it, it is not immediately clear which TC the class represents. This
  is unlike PRIO with its straightforward classid scheme. When DRR is
  combined with PRIO, the relationship between classes and TCs gets even
  more murky.

  This is a problem for users as well: the TC mapping is rather important
  for (devlink) shared buffer configuration and (ethtool) counters.

So instead, this patch set introduces a new Qdisc, which is based on
802.1Qaz wording. It is PRIO-like in how it is configured, meaning one
needs to specify how many bands there are, how many are strict and how many
are ETS, quanta for the latter, and priomap.

The new Qdisc operates like the PRIO / DRR combo would when configured as
per the standard. The strict classes, if any, are tried for traffic first.
When there's no traffic in any of the strict queues, the ETS ones (if any)
are treated in the same way as in DRR.

The chosen interface makes the overall system both reasonably easy to
configure, and reasonably easy to offload. The extra code to support ETS in
mlxsw (which already supports PRIO) is about 150 lines, of which perhaps 20
lines is bona fide new business logic.

Credit-based shaping transmission selection algorithm can be configured by
adding a CBS Qdisc under one of the strict bands (e.g. TBF can be used to a
similar effect as well). As a non-work-conserving Qdisc, CBS can't be
hooked under the ETS bands. This is detected and handled identically to DRR
Qdisc at runtime. Note that offloading CBS is not subject of this patchset.

The patchset proceeds in four stages:

- Patches #1-#3 are cleanups.
- Patches #4 and #5 contain the new Qdisc.
- Patches #6 and #7 update mlxsw to offload the new Qdisc.
- Patches #8-#10 add selftests for ETS.

Examples:

- Add a Qdisc with 6 bands, 3 strict and 3 ETS with 45%-30%-25% weights:

    # tc qdisc add dev swp1 root handle 1: \
	ets strict 3 quanta 4500 3000 2500 priomap 0 1 1 1 2 3 4 5
    # tc qdisc sh dev swp1
    qdisc ets 1: root refcnt 2 bands 6 strict 3 quanta 4500 3000 2500 priomap 0 1 1 1 2 3 4 5 5 5 5 5 5 5 5 5

- Tweak quantum of one of the classes of the previous Qdisc:

    # tc class ch dev swp1 classid 1:4 ets quantum 1000
    # tc qdisc sh dev swp1
    qdisc ets 1: root refcnt 2 bands 6 strict 3 quanta 1000 3000 2500 priomap 0 1 1 1 2 3 4 5 5 5 5 5 5 5 5 5
    # tc class ch dev swp1 classid 1:3 ets quantum 1000
    Error: Strict bands do not have a configurable quantum.

- Purely strict Qdisc with 1:1 mapping between priorities and TCs:

    # tc qdisc add dev swp1 root handle 1: \
	ets strict 8 priomap 7 6 5 4 3 2 1 0
    # tc qdisc sh dev swp1
    qdisc ets 1: root refcnt 2 bands 8 strict 8 priomap 7 6 5 4 3 2 1 0 7 7 7 7 7 7 7 7

- Use "bands" to specify number of bands explicitly. Underspecified bands
  are implicitly ETS and their quantum is taken from MTU. The following
  thus gives each band the same weight:

    # tc qdisc add dev swp1 root handle 1: \
	ets bands 8 priomap 7 6 5 4 3 2 1 0
    # tc qdisc sh dev swp1
    qdisc ets 1: root refcnt 2 bands 8 quanta 1514 1514 1514 1514 1514 1514 1514 1514 priomap 7 6 5 4 3 2 1 0 7 7 7 7 7 7 7 7

v2:
- This addresses points raised by David Miller.
- Patch #4:
    - sch_ets.c: Add a comment with description of the Qdisc and the
      dequeuing algorithm.
    - Kconfig: Add a high-level description to the help blurb.

v1:
- No changes, first upstream submission after RFC.

v3 (internal):
- This addresses review from Jiri Pirko.
- Patch #3:
    - Rename to _HR_ instead of to _HIERARCHY_.
- Patch #4:
    - pkt_sched.h: Keep all the TCA_ETS_ constants in one enum.
    - pkt_sched.h: Rename TCA_ETS_BANDS to _NBANDS, _STRICT to _NSTRICT,
      _BAND_QUANTUM to _QUANTA_BAND and _PMAP_BAND to _PRIOMAP_BAND.
    - sch_ets.c: Update to reflect the above changes. Add a new policy,
      ets_class_policy, which is used when parsing class changes.
      Currently that policy is the same as the quanta policy, but that
      might change.
    - sch_ets.c: Move MTU handling from ets_quantum_parse() to the one
      caller that makes use of it.
    - sch_ets.c: ets_qdisc_priomap_parse(): WARN_ON_ONCE on invalid
      attribute instead of returning an extack.
- Patch #6:
    - __mlxsw_sp_qdisc_ets_replace(): Pass the weights argument to this
      function in this patch already. Drop the weight computation.
    - mlxsw_sp_qdisc_prio_replace(): Rename "quanta" to "zeroes" and
      pass for the abovementioned "weights".
    - mlxsw_sp_qdisc_prio_graft(): Convert to a wrapper around
      __mlxsw_sp_qdisc_ets_graft(), instead of invoking the latter
      directly from mlxsw_sp_setup_tc_prio().
    - Update to follow the _HIERARCHY_ -> _HR_ renaming.
- Patch #7:
    - __mlxsw_sp_qdisc_ets_replace(): The "weights" argument passing and
      weight computation removal are now done in a previous patch.
    - mlxsw_sp_setup_tc_ets(): Drop case TC_ETS_REPLACE, which is handled
      earlier in the function.
- Patch #3 (iproute2):
    - Add an example output to the commit message.
    - tc-ets.8: Fix output of two examples.
    - tc-ets.8: Describe default values of "bands", "quanta".
    - q_ets.c: A number of fixes in error messages.
    - q_ets.c: Comment formatting: /*padding*/ -> /* padding */
    - q_ets.c: parse_nbands: Move duplicate checking to callers.
    - q_ets.c: Don't accept both "quantum" and "quanta" as equivalent.

v2 (internal):
- This addresses review from Ido Schimmel and comments from Alexander
  Kushnarov.
- Patch #2:
    - s/coment/comment in the commit message.
- Patch #4:
    - sch_ets: ets_class_is_strict(), ets_class_id(): Constify an argument
    - ets_class_find(): RXTify
- Patch #3 (iproute2):
    - tc-ets.8: some spelling fixes
    - tc-ets.8: add another example
    - tc.8: add an ETS to "CLASSFUL QDISCS" section

v1 (internal):
- This addresses RFC reviews from Ido Schimmel and Roman Mashak, bugs found
  by Alexander Petrovskiy and myself, and other improvements.
- Patch #2:
    - Expand the explanation with an explicit example.
- Patch #4:
    - Kconfig: s/sch_drr/sch_ets/
    - sch_ets: Reorder includes to be in alphabetical order
    - sch_ets: ets_quantum_parse(): Rename the return-pointer argument
      from pquantum to quantum, and use it directly, not going through a
      local temporary.
    - sch_ets: ets_qdisc_quanta_parse(): Convert syntax of function
      argument "quanta" from an array to a pointer.
    - sch_ets: ets_qdisc_priomap_parse(): Likewise with "priomap".
    - sch_ets: ets_qdisc_quanta_parse(), ets_qdisc_priomap_parse(): Invoke
      __nla_validate_nested directly instead of nl80211_validate_nested().
    - sch_ets: ets_qdisc_quanta_parse(): WARN_ON_ONCE on invalid attribute
      instead of returning an extack.
    - sch_ets: ets_qdisc_change(): Make the last band the default one for
      unmentioned priomap priorities.
    - sch_ets: Fix a panic when an offloaded child in a bandwidth-sharing
      band notified its ETS parent.
    - sch_ets: When ungrafting, add the newly-created invisible FIFO to
      the Qdisc hash
- Patch #5:
    - pkt_cls.h: Note that quantum=0 signifies a strict band.
    - Fix error path handling when ets_offload_dump() fails.
- Patch #6:
    - __mlxsw_sp_qdisc_ets_replace(): Convert syntax of function arguments
      "quanta" and "priomap" from arrays to pointers.
- Patch #7:
    - __mlxsw_sp_qdisc_ets_replace(): Convert syntax of function argument
      "weights" from an array to a pointer.
- Patch #9:
    - mlxsw/sch_ets.sh: Add a comment explaining packet prioritization.
    - Adjust the whole suite to allow testing of traffic classifiers
      in addition to testing priomap.
- Patch #10:
    - Add a number of new tests to test default priomap band, overlarge
      number of bands, zeroes in quanta, and altogether missing quanta.
- Patch #1 (iproute2):
    - State motivation for inclusion of this patch in the patcheset in the
      commit message.
- Patch #3 (iproute2):
    - tc-ets.8: it is now December
    - tc-ets.8: explain inactivity WRT using non-WC Qdiscs under ETS band
    - tc-ets.8: s/flow/band in explanation of quantum
    - tc-ets.8: explain what happens with priorities not covered by priomap
    - tc-ets.8: default priomap band is now the last one
    - q_ets.c: ets_parse_opt(): Remove unnecessary initialization of
      priomap and quanta.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6bff0017
    • P
      selftests: qdiscs: Add test coverage for ETS Qdisc · 82c664b6
      由 Petr Machata 提交于 
      Add TDC coverage for the new ETS Qdisc.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      82c664b6
    • P
      selftests: forwarding: sch_ets: Add test coverage for ETS Qdisc · ddd3fd75
      由 Petr Machata 提交于 
      This tests the newly-added ETS Qdisc. It runs two to three streams of
traffic, each with a different priority. ETS Qdisc is supposed to allocate
bandwidth according to the DRR algorithm and given weights. After running
the traffic for a while, counters are compared for each stream to check
that the expected ratio is in fact observed.

In order for the DRR process to kick in, a traffic bottleneck must exist in
the first place. In slow path, such bottleneck can be implemented by
wrapping the ETS Qdisc inside a TBF or other shaper. This might however
make the configuration unoffloadable. Instead, on HW datapath, the
bottleneck would be set up by lowering port speed and configuring shared
buffer suitably.

Therefore the test is structured as a core component that implements the
testing, with two wrapper scripts that implement the details of slow path
resp. fast path configuration.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ddd3fd75
    • P
      selftests: forwarding: Move start_/stop_traffic from mlxsw to lib.sh · 4cf9b8f9
      由 Petr Machata 提交于 
      These two functions are used for starting several streams of traffic, and
then stopping them later. They will be handy for the test coverage of ETS
Qdisc. Move them from mlxsw-specific qos_lib.sh to the generic lib.sh.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4cf9b8f9
    • P
      mlxsw: spectrum_qdisc: Support offloading of ETS Qdisc · 19f405b9
      由 Petr Machata 提交于 
      Handle TC_SETUP_QDISC_ETS, add a new ops structure for the ETS Qdisc.
Invoke the extended prio handlers implemented in the previous patch. For
stats ops, invoke directly the prio callbacks, which are not sensitive to
differences between PRIO and ETS.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      19f405b9
    • P
      mlxsw: spectrum_qdisc: Generalize PRIO offload to support ETS · 7917f52a
      由 Petr Machata 提交于 
      Thanks to the similarity between PRIO and ETS it is possible to simply
reuse most of the code for offloading PRIO Qdisc. Extract the common
functionality into separate functions, making the current PRIO handlers
thin API adapters.

Extend the new functions to pass quanta for individual bands, which allows
configuring a subset of bands as WRR. Invoke mlxsw_sp_port_ets_set() as
appropriate to de/configure WRR-ness and weight of individual bands.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7917f52a
    • P
      net: sch_ets: Make the ETS qdisc offloadable · d35eb52b
      由 Petr Machata 提交于 
      Add hooks at appropriate points to make it possible to offload the ETS
Qdisc.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d35eb52b
    • P
      net: sch_ets: Add a new Qdisc · dcc68b4d
      由 Petr Machata 提交于 
      Introduces a new Qdisc, which is based on 802.1Q-2014 wording. It is
PRIO-like in how it is configured, meaning one needs to specify how many
bands there are, how many are strict and how many are dwrr, quanta for the
latter, and priomap.

The new Qdisc operates like the PRIO / DRR combo would when configured as
per the standard. The strict classes, if any, are tried for traffic first.
When there's no traffic in any of the strict queues, the ETS ones (if any)
are treated in the same way as in DRR.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dcc68b4d
    • P
      mlxsw: spectrum: Rename MLXSW_REG_QEEC_HIERARCY_* enumerators · 9cf9b925
      由 Petr Machata 提交于 
      These enums want to be named MLXSW_REG_QEEC_HIERARCHY_, but due to a typo
lack the second H. That is confusing and complicates searching.

But actually the enumerators should be named _HR_, because that is how
their enum type is called. So rename them as appropriate.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9cf9b925
    • P
      mlxsw: spectrum_qdisc: Clarify a comment · 5bc146c9
      由 Petr Machata 提交于 
      Expand the comment at mlxsw_sp_qdisc_prio_graft() to make the problem that
this function is trying to handle clearer.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5bc146c9
    • P
      net: pkt_cls: Clarify a comment · 9586a992
      由 Petr Machata 提交于 
      The bit about negating HW backlog left me scratching my head. Clarify the
comment.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9586a992
    • K
      sch_cake: drop unused variable tin_quantum_prio · cbd22f17
      由 Kevin 'ldir' Darbyshire-Bryant 提交于 
      Turns out tin_quantum_prio isn't used anymore and is a leftover from a
previous implementation of diffserv tins.  Since the variable isn't used
in any calculations it can be eliminated.

Drop variable and places where it was set.  Rename remaining variable
and consolidate naming of intermediate variables that set it.
Signed-off-by: NKevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cbd22f17
    • D
      Merge branch 's390-next' · dcbe4e95
      由 David S. Miller 提交于 
      Julian Wiedmann says:

====================
s390/qeth: features 2019-12-18

please apply the following patch series to your net-next tree.
Nothing major, just the usual mix of small improvements and cleanups.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dcbe4e95
    • J
      s390/qeth: make use of napi_schedule_irqoff() · 334b49de
      由 Julian Wiedmann 提交于 
      qeth_qdio_start_poll() is called from the qdio layer's IRQ handler,
while IRQs are masked.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      334b49de
    • J
      s390/qeth: consolidate helpers for capability checking · 52f82bf1
      由 Julian Wiedmann 提交于 
      Convert the old code to use struct qeth_ipa_caps, and while at it remove
all unused helper macros.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      52f82bf1
    • J
      s390/qeth: stop yielding the ip_lock during IPv4 registration · adee2592
      由 Julian Wiedmann 提交于 
      As commit df2a2a52 ("s390/qeth: convert IP table spinlock to mutex")
converted the ip_lock to a mutex, we no longer have to yield it while
the subsequent IO sleep-waits for completion.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      adee2592
    • J
      s390/qeth: don't raise NETDEV_REBOOT event from L3 offline path · b6beb62a
      由 Julian Wiedmann 提交于 
      This is a leftover from back when a recovery action didn't go through
dev_close(), and was meant to shoot down all remaining af_iucv sockets
on the interface.

Now that the offline path always calls dev_close(), the
NETDEV_GOING_DOWN event from __dev_close_many() is sufficient and this
hack can be removed.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b6beb62a