[v2,0/4] eal: update public API to use stdatomic atomics

  Update EAL public API to use standard C11 atomics. In accordance with
technical board discussion February 2023.
http://mails.dpdk.org/archives/dev/2023-February/263516.html

This initial series makes no attempt to adapt every use of builtin atomics
from GCC it intends only to adapt the public API of the EAL presented as
a compatibility surface to applications.

Further series will be submitted to adapt the rest of DPDK to use standard
atomics that are 'internal' and not do not straddle the EAL API.

The choice has been made to break these two changes apart to allow more
precise analysis of any potential performance impact this change or
subsequent changes may introduce.

Additionally, it is not possible to break the commits up per driver/lib as
both the provider and consumer of the APIs need to be changed in the same
commit to maintain non-broken build and function.

Finally, the first patch in this series is a duplication of Bruce Richardson
series https://patchwork.dpdk.org/project/dpdk/list/?series=29048 and is
only being provided to enable the CI run on this series. It is expected that
Bruce's series when committed will allow the build: require minimum c11 compiler
here to be dropped from this series.

v2:
  * remove volatile qualification from variables, structure fields and
    parameters that have been qualified _Atomic
  * restore removal of #include <rte_atomic.h> in rte_ring_core.h the ring
    library still uses other rte_atomic APIs and types that are not replaced
    by the standard or compiler intrinsics
  * add missing adaption to stdatomic in ring/rte_ring_c11_pvt.h

Tyler Retzlaff (4):
  build: require minimum c11 compiler
  devtools: forbid use of GCC atomic builtins
  eal: adapt rte pause APIs to use C11 atomics
  eal: adapt rte spinlock and rwlock APIs to use C11 atomics

 app/test-bbdev/test_bbdev_perf.c         | 123 ++++++++++++++++++++-----------
 app/test/test_func_reentrancy.c          |   8 +-
 app/test/test_mcslock.c                  |  12 +--
 app/test/test_mempool_perf.c             |   8 +-
 app/test/test_pflock.c                   |  12 +--
 app/test/test_pmd_perf.c                 |  10 +--
 app/test/test_ring_perf.c                |   8 +-
 app/test/test_rwlock.c                   |   8 +-
 app/test/test_spinlock.c                 |   8 +-
 app/test/test_stack_perf.c               |  12 +--
 app/test/test_ticketlock.c               |   8 +-
 app/test/test_timer.c                    |  16 ++--
 devtools/checkpatches.sh                 |   8 ++
 drivers/event/opdl/opdl_ring.c           |  47 ++++++------
 drivers/net/failsafe/meson.build         |   1 -
 drivers/net/thunderx/nicvf_rxtx.c        |   5 +-
 drivers/net/thunderx/nicvf_struct.h      |   2 +-
 lib/bpf/bpf_pkt.c                        |   4 +-
 lib/distributor/distributor_private.h    |   2 +-
 lib/distributor/rte_distributor_single.c |  44 +++++------
 lib/eal/arm/include/rte_pause_64.h       |  28 +++----
 lib/eal/common/eal_common_errno.c        |   1 +
 lib/eal/common/eal_memcfg.h              |   2 +-
 lib/eal/include/generic/rte_pause.h      |  52 ++++++-------
 lib/eal/include/generic/rte_rwlock.h     |  46 ++++++------
 lib/eal/include/generic/rte_spinlock.h   |  21 +++---
 lib/eal/include/rte_mcslock.h            |  12 +--
 lib/eal/include/rte_pflock.h             |  22 +++---
 lib/eal/include/rte_ticketlock.h         |   8 +-
 lib/eal/loongarch/include/rte_pause.h    |   2 -
 lib/eal/ppc/include/rte_pause.h          |   2 -
 lib/eal/riscv/include/rte_pause.h        |   2 -
 lib/eal/x86/include/rte_spinlock.h       |   2 +-
 lib/ring/rte_ring_c11_pvt.h              |  28 +++----
 lib/ring/rte_ring_core.h                 |   4 +-
 lib/ring/rte_ring_generic_pvt.h          |  19 +++--
 lib/ring/rte_ring_peek_elem_pvt.h        |   2 +-
 meson.build                              |   1 +
 38 files changed, 326 insertions(+), 274 deletions(-)
  

> From: Tyler Retzlaff [mailto:roretzla@linux.microsoft.com]
> Sent: Tuesday, 1 August 2023 07.04
> 
> Update EAL public API to use standard C11 atomics. In accordance with
> technical board discussion February 2023.
> http://mails.dpdk.org/archives/dev/2023-February/263516.html
> 
> This initial series makes no attempt to adapt every use of builtin atomics
> from GCC it intends only to adapt the public API of the EAL presented as
> a compatibility surface to applications.
> 
> Further series will be submitted to adapt the rest of DPDK to use standard
> atomics that are 'internal' and not do not straddle the EAL API.
> 
> The choice has been made to break these two changes apart to allow more
> precise analysis of any potential performance impact this change or
> subsequent changes may introduce.
> 
> Additionally, it is not possible to break the commits up per driver/lib as
> both the provider and consumer of the APIs need to be changed in the same
> commit to maintain non-broken build and function.
> 
> Finally, the first patch in this series is a duplication of Bruce Richardson
> series https://patchwork.dpdk.org/project/dpdk/list/?series=29048 and is
> only being provided to enable the CI run on this series. It is expected that
> Bruce's series when committed will allow the build: require minimum c11
> compiler
> here to be dropped from this series.
> 
> v2:
>   * remove volatile qualification from variables, structure fields and
>     parameters that have been qualified _Atomic
>   * restore removal of #include <rte_atomic.h> in rte_ring_core.h the ring
>     library still uses other rte_atomic APIs and types that are not replaced
>     by the standard or compiler intrinsics
>   * add missing adaption to stdatomic in ring/rte_ring_c11_pvt.h

Series-acked-by: Morten Brørup <mb@smartsharesystems.com>
  

top post

just a heads up on this series, please defer review until v3 is
submitted.

clang is stricter in atomic type enforcement than gcc so a new revision
is needed that removes the direct use of intrinsics replacing them with
the standard atomics for all _Atomic types.

thanks

On Mon, Jul 31, 2023 at 10:03:50PM -0700, Tyler Retzlaff wrote:
> Update EAL public API to use standard C11 atomics. In accordance with
> technical board discussion February 2023.
> http://mails.dpdk.org/archives/dev/2023-February/263516.html
> 
> This initial series makes no attempt to adapt every use of builtin atomics
> from GCC it intends only to adapt the public API of the EAL presented as
> a compatibility surface to applications.
> 
> Further series will be submitted to adapt the rest of DPDK to use standard
> atomics that are 'internal' and not do not straddle the EAL API.
> 
> The choice has been made to break these two changes apart to allow more
> precise analysis of any potential performance impact this change or
> subsequent changes may introduce.
> 
> Additionally, it is not possible to break the commits up per driver/lib as
> both the provider and consumer of the APIs need to be changed in the same
> commit to maintain non-broken build and function.
> 
> Finally, the first patch in this series is a duplication of Bruce Richardson
> series https://patchwork.dpdk.org/project/dpdk/list/?series=29048 and is
> only being provided to enable the CI run on this series. It is expected that
> Bruce's series when committed will allow the build: require minimum c11 compiler
> here to be dropped from this series.
> 
> v2:
>   * remove volatile qualification from variables, structure fields and
>     parameters that have been qualified _Atomic
>   * restore removal of #include <rte_atomic.h> in rte_ring_core.h the ring
>     library still uses other rte_atomic APIs and types that are not replaced
>     by the standard or compiler intrinsics
>   * add missing adaption to stdatomic in ring/rte_ring_c11_pvt.h
> 
> Tyler Retzlaff (4):
>   build: require minimum c11 compiler
>   devtools: forbid use of GCC atomic builtins
>   eal: adapt rte pause APIs to use C11 atomics
>   eal: adapt rte spinlock and rwlock APIs to use C11 atomics
> 
>  app/test-bbdev/test_bbdev_perf.c         | 123 ++++++++++++++++++++-----------
>  app/test/test_func_reentrancy.c          |   8 +-
>  app/test/test_mcslock.c                  |  12 +--
>  app/test/test_mempool_perf.c             |   8 +-
>  app/test/test_pflock.c                   |  12 +--
>  app/test/test_pmd_perf.c                 |  10 +--
>  app/test/test_ring_perf.c                |   8 +-
>  app/test/test_rwlock.c                   |   8 +-
>  app/test/test_spinlock.c                 |   8 +-
>  app/test/test_stack_perf.c               |  12 +--
>  app/test/test_ticketlock.c               |   8 +-
>  app/test/test_timer.c                    |  16 ++--
>  devtools/checkpatches.sh                 |   8 ++
>  drivers/event/opdl/opdl_ring.c           |  47 ++++++------
>  drivers/net/failsafe/meson.build         |   1 -
>  drivers/net/thunderx/nicvf_rxtx.c        |   5 +-
>  drivers/net/thunderx/nicvf_struct.h      |   2 +-
>  lib/bpf/bpf_pkt.c                        |   4 +-
>  lib/distributor/distributor_private.h    |   2 +-
>  lib/distributor/rte_distributor_single.c |  44 +++++------
>  lib/eal/arm/include/rte_pause_64.h       |  28 +++----
>  lib/eal/common/eal_common_errno.c        |   1 +
>  lib/eal/common/eal_memcfg.h              |   2 +-
>  lib/eal/include/generic/rte_pause.h      |  52 ++++++-------
>  lib/eal/include/generic/rte_rwlock.h     |  46 ++++++------
>  lib/eal/include/generic/rte_spinlock.h   |  21 +++---
>  lib/eal/include/rte_mcslock.h            |  12 +--
>  lib/eal/include/rte_pflock.h             |  22 +++---
>  lib/eal/include/rte_ticketlock.h         |   8 +-
>  lib/eal/loongarch/include/rte_pause.h    |   2 -
>  lib/eal/ppc/include/rte_pause.h          |   2 -
>  lib/eal/riscv/include/rte_pause.h        |   2 -
>  lib/eal/x86/include/rte_spinlock.h       |   2 +-
>  lib/ring/rte_ring_c11_pvt.h              |  28 +++----
>  lib/ring/rte_ring_core.h                 |   4 +-
>  lib/ring/rte_ring_generic_pvt.h          |  19 +++--
>  lib/ring/rte_ring_peek_elem_pvt.h        |   2 +-
>  meson.build                              |   1 +
>  38 files changed, 326 insertions(+), 274 deletions(-)
> 
> -- 
> 1.8.3.1