DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Tyler Retzlaff" <roretzla@linux.microsoft.com>, <dev@dpdk.org>
Cc: <david.marchand@redhat.com>, <thomas@monjalon.net>,
	<Honnappa.Nagarahalli@arm.com>, <bruce.richardson@intel.com>
Subject: RE: [PATCH v2] eal: introduce atomics abstraction
Date: Thu, 9 Feb 2023 09:05:46 +0100	[thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D87718@smartserver.smartshare.dk> (raw)
In-Reply-To: <1675892618-31755-2-git-send-email-roretzla@linux.microsoft.com>

> From: Tyler Retzlaff [mailto:roretzla@linux.microsoft.com]
> Sent: Wednesday, 8 February 2023 22.44
> 
> Introduce atomics abstraction that permits optional use of standard C11
> atomics when meson is provided the new enable_stdatomics=true option.
> 
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> ---

Looks good. A few minor suggestions about implementation only.

With or without suggested modifications,

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


>  config/meson.build                     | 11 ++++
>  lib/eal/arm/include/rte_atomic_32.h    |  6 ++-
>  lib/eal/arm/include/rte_atomic_64.h    |  6 ++-
>  lib/eal/include/generic/rte_atomic.h   | 96
> +++++++++++++++++++++++++++++++++-
>  lib/eal/loongarch/include/rte_atomic.h |  6 ++-
>  lib/eal/ppc/include/rte_atomic.h       |  6 ++-
>  lib/eal/riscv/include/rte_atomic.h     |  6 ++-
>  lib/eal/x86/include/rte_atomic.h       |  8 ++-
>  meson_options.txt                      |  2 +
>  9 files changed, 139 insertions(+), 8 deletions(-)
> 
> diff --git a/config/meson.build b/config/meson.build
> index 26f3168..25dd628 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -255,6 +255,17 @@ endif
>  # add -include rte_config to cflags
>  add_project_arguments('-include', 'rte_config.h', language: 'c')
> 
> +stdc_atomics_enabled = get_option('enable_stdatomics')
> +dpdk_conf.set('RTE_STDC_ATOMICS', stdc_atomics_enabled)
> +
> +if stdc_atomics_enabled
> +if cc.get_id() == 'gcc' or cc.get_id() == 'clang'
> +    add_project_arguments('-std=gnu11', language: 'c')
> +else
> +    add_project_arguments('-std=c11', language: 'c')
> +endif
> +endif
> +
>  # enable extra warnings and disable any unwanted warnings
>  # -Wall is added by default at warning level 1, and -Wextra
>  # at warning level 2 (DPDK default)
> diff --git a/lib/eal/arm/include/rte_atomic_32.h
> b/lib/eal/arm/include/rte_atomic_32.h
> index c00ab78..7088a12 100644
> --- a/lib/eal/arm/include/rte_atomic_32.h
> +++ b/lib/eal/arm/include/rte_atomic_32.h
> @@ -34,9 +34,13 @@
>  #define rte_io_rmb() rte_rmb()
> 
>  static __rte_always_inline void
> -rte_atomic_thread_fence(int memorder)
> +rte_atomic_thread_fence(rte_memory_order memorder)
>  {
> +#ifdef RTE_STDC_ATOMICS
> +	atomic_thread_fence(memorder);
> +#else
>  	__atomic_thread_fence(memorder);
> +#endif
>  }
> 
>  #ifdef __cplusplus
> diff --git a/lib/eal/arm/include/rte_atomic_64.h
> b/lib/eal/arm/include/rte_atomic_64.h
> index 6047911..7f02c57 100644
> --- a/lib/eal/arm/include/rte_atomic_64.h
> +++ b/lib/eal/arm/include/rte_atomic_64.h
> @@ -38,9 +38,13 @@
>  #define rte_io_rmb() rte_rmb()
> 
>  static __rte_always_inline void
> -rte_atomic_thread_fence(int memorder)
> +rte_atomic_thread_fence(rte_memory_order memorder)
>  {
> +#ifdef RTE_STDC_ATOMICS
> +	atomic_thread_fence(memorder);
> +#else
>  	__atomic_thread_fence(memorder);
> +#endif
>  }
> 
>  /*------------------------ 128 bit atomic operations -----------------
> --------*/
> diff --git a/lib/eal/include/generic/rte_atomic.h
> b/lib/eal/include/generic/rte_atomic.h
> index f5c49a9..392d928 100644
> --- a/lib/eal/include/generic/rte_atomic.h
> +++ b/lib/eal/include/generic/rte_atomic.h
> @@ -110,6 +110,100 @@
> 
>  #endif /* __DOXYGEN__ */
> 
> +#ifdef RTE_STDC_ATOMICS
> +
> +#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L ||
> defined(__STDC_NO_ATOMICS__)
> +#error compiler does not support C11 standard atomics
> +#else
> +#include <stdatomic.h>
> +#endif
> +
> +#define __rte_atomic _Atomic
> +
> +typedef int rte_memory_order;

I would prefer enum for rte_memory_order:

typedef enum {
    rte_memory_order_relaxed = memory_order_relaxed,
    rte_memory_order_consume = memory_order_consume,
    rte_memory_order_acquire = memory_order_acquire,
    rte_memory_order_release = memory_order_release,
    rte_memory_order_acq_rel = memory_order_acq_rel,
    rte_memory_order_seq_cst = memory_order_seq_cst
} rte_memory_order;

> +
> +#define rte_memory_order_relaxed memory_order_relaxed
> +#define rte_memory_order_consume memory_order_consume
> +#define rte_memory_order_acquire memory_order_acquire
> +#define rte_memory_order_release memory_order_release
> +#define rte_memory_order_acq_rel memory_order_acq_rel
> +#define rte_memory_order_seq_cst memory_order_seq_cst
> +
> +#define rte_atomic_store_explicit(obj, desired, order) \
> +	atomic_store_explicit(obj, desired, order)
> +
> +#define rte_atomic_load_explicit(obj, order) \
> +	atomic_load_explicit(obj, order)
> +
> +#define rte_atomic_exchange_explicit(obj, desired, order) \
> +	atomic_exchange_explicit(obj, desired, order)
> +
> +#define rte_atomic_compare_exchange_strong_explicit(obj, expected,
> desired, success, fail) \
> +	atomic_compare_exchange_strong_explicit(obj, expected, desired,
> success, fail)
> +
> +#define rte_atomic_compare_exchange_weak_explicit(obj, expected,
> desired, success, fail) \
> +	atomic_compare_exchange_weak_explicit(obj, expected, desired,
> success, fail)
> +
> +#define rte_atomic_fetch_add_explicit(obj, arg, order) \
> +	atomic_fetch_add_explicit(obj, arg, order)
> +
> +#define rte_atomic_fetch_sub_explicit(obj, arg, order) \
> +	atomic_fetch_sub_explicit(obj, arg, order)
> +
> +#define rte_atomic_fetch_or_explicit(obj, arg, order) \
> +	atomic_fetch_or_explicit(obj, arg, order)
> +
> +#define rte_atomic_fetch_xor_explicit(obj, arg, order) \
> +	atomic_fetch_xor_explicit(obj, arg, order)
> +
> +#define rte_atomic_fetch_and_explicit(obj, arg, order) \
> +	atomic_fetch_and_explicit(obj, arg, order)
> +
> +#else
> +
> +#define __rte_atomic
> +
> +typedef int rte_memory_order;
> +
> +#define rte_memory_order_relaxed __ATOMIC_RELAXED
> +#define rte_memory_order_consume __ATOMIC_CONSUME
> +#define rte_memory_order_acquire __ATOMIC_ACQUIRE
> +#define rte_memory_order_release __ATOMIC_RELEASE
> +#define rte_memory_order_acq_rel __ATOMIC_ACQ_REL
> +#define rte_memory_order_seq_cst __ATOMIC_SEQ_CST

Prefer enum for rte_memory_order:

typedef enum {
    rte_memory_order_relaxed = __ATOMIC_RELAXED,
    rte_memory_order_consume = __ATOMIC_CONSUME,
    rte_memory_order_acquire = __ATOMIC_ACQUIRE,
    rte_memory_order_release = __ATOMIC_RELEASE,
    rte_memory_order_acq_rel = __ATOMIC_ACQ_REL,
    rte_memory_order_seq_cst = __ATOMIC_SEQ_CST
} rte_memory_order;

> +
> +#define rte_atomic_store_explicit(obj, desired, order) \
> +	__atomic_store_n(obj, desired, order)
> +
> +#define rte_atomic_load_explicit(obj, order) \
> +	__atomic_load_n(obj, order)
> +
> +#define rte_atomic_exchange_explicit(obj, desired, order) \
> +	__atomic_exchange_n(obj, desired, order)
> +
> +#define rte_atomic_compare_exchange_strong_explicit(obj, expected,
> desired, success, fail) \
> +	__atomic_compare_exchange_n(obj, expected, desired, 0, success,
> fail)

The type of the "weak" parameter to __atomic_compare_exchange_n() is bool, not int, so use "false" instead of 0. There is probably no practical difference, so I'll leave it up to you.

You might need to include <stdbool.h> for this... I haven't checked.

> +
> +#define rte_atomic_compare_exchange_weak_explicit(obj, expected,
> desired, success, fail) \
> +	__atomic_compare_exchange_n(obj, expected, desired, 1, success,
> fail)

Same as above: Use "true" instead of 1.

> +
> +#define rte_atomic_fetch_add_explicit(obj, arg, order) \
> +	__atomic_fetch_add(obj, arg, order)
> +
> +#define rte_atomic_fetch_sub_explicit(obj, arg, order) \
> +	__atomic_fetch_sub(obj, arg, order)
> +
> +#define rte_atomic_fetch_or_explicit(obj, arg, order) \
> +	__atomic_fetch_or(obj, arg, order)
> +
> +#define rte_atomic_fetch_xor_explicit(obj, arg, order) \
> +	__atomic_fetch_xor(obj, arg, order)
> +
> +#define rte_atomic_fetch_and_explicit(obj, arg, order) \
> +	__atomic_fetch_and(obj, arg, order)
> +
> +#endif
> +
>  /**
>   * Compiler barrier.
>   *
> @@ -123,7 +217,7 @@
>  /**
>   * Synchronization fence between threads based on the specified memory
> order.
>   */
> -static inline void rte_atomic_thread_fence(int memorder);
> +static inline void rte_atomic_thread_fence(rte_memory_order memorder);
> 
>  /*------------------------- 16 bit atomic operations -----------------
> --------*/
> 
> diff --git a/lib/eal/loongarch/include/rte_atomic.h
> b/lib/eal/loongarch/include/rte_atomic.h
> index 3c82845..66aa0c8 100644
> --- a/lib/eal/loongarch/include/rte_atomic.h
> +++ b/lib/eal/loongarch/include/rte_atomic.h
> @@ -35,9 +35,13 @@
>  #define rte_io_rmb()	rte_mb()
> 
>  static __rte_always_inline void
> -rte_atomic_thread_fence(int memorder)
> +rte_atomic_thread_fence(rte_memory_order memorder)
>  {
> +#ifdef RTE_STDC_ATOMICS
> +	atomic_thread_fence(memorder);
> +#else
>  	__atomic_thread_fence(memorder);
> +#endif
>  }
> 
>  #ifdef __cplusplus
> diff --git a/lib/eal/ppc/include/rte_atomic.h
> b/lib/eal/ppc/include/rte_atomic.h
> index 663b4d3..a428a83 100644
> --- a/lib/eal/ppc/include/rte_atomic.h
> +++ b/lib/eal/ppc/include/rte_atomic.h
> @@ -38,9 +38,13 @@
>  #define rte_io_rmb() rte_rmb()
> 
>  static __rte_always_inline void
> -rte_atomic_thread_fence(int memorder)
> +rte_atomic_thread_fence(rte_memory_order memorder)
>  {
> +#ifdef RTE_STDC_ATOMICS
> +	atomic_thread_fence(memorder);
> +#else
>  	__atomic_thread_fence(memorder);
> +#endif
>  }
> 
>  /*------------------------- 16 bit atomic operations -----------------
> --------*/
> diff --git a/lib/eal/riscv/include/rte_atomic.h
> b/lib/eal/riscv/include/rte_atomic.h
> index 4b4633c..3c203a9 100644
> --- a/lib/eal/riscv/include/rte_atomic.h
> +++ b/lib/eal/riscv/include/rte_atomic.h
> @@ -40,9 +40,13 @@
>  #define rte_io_rmb()	asm volatile("fence ir, ir" : : : "memory")
> 
>  static __rte_always_inline void
> -rte_atomic_thread_fence(int memorder)
> +rte_atomic_thread_fence(rte_memory_order memorder)
>  {
> +#ifdef RTE_STDC_ATOMICS
> +	atomic_thread_fence(memorder);
> +#else
>  	__atomic_thread_fence(memorder);
> +#endif
>  }
> 
>  #ifdef __cplusplus
> diff --git a/lib/eal/x86/include/rte_atomic.h
> b/lib/eal/x86/include/rte_atomic.h
> index f2ee1a9..02d8b12 100644
> --- a/lib/eal/x86/include/rte_atomic.h
> +++ b/lib/eal/x86/include/rte_atomic.h
> @@ -87,12 +87,16 @@
>   * used instead.
>   */
>  static __rte_always_inline void
> -rte_atomic_thread_fence(int memorder)
> +rte_atomic_thread_fence(rte_memory_order memorder)
>  {
> -	if (memorder == __ATOMIC_SEQ_CST)
> +	if (memorder == rte_memory_order_seq_cst)
>  		rte_smp_mb();
>  	else
> +#ifdef RTE_STDC_ATOMICS
> +		atomic_thread_fence(memorder);
> +#else
>  		__atomic_thread_fence(memorder);
> +#endif
>  }
> 
>  /*------------------------- 16 bit atomic operations -----------------
> --------*/
> diff --git a/meson_options.txt b/meson_options.txt
> index 0852849..acbcbb8 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -46,6 +46,8 @@ option('mbuf_refcnt_atomic', type: 'boolean', value:
> true, description:
>         'Atomically access the mbuf refcnt.')
>  option('platform', type: 'string', value: 'native', description:
>         'Platform to build, either "native", "generic" or a SoC. Please
> refer to the Linux build guide for more information.')
> +option('enable_stdatomics', type: 'boolean', value: false,
> description:
> +       'enable use of standard C11 atomics.')
>  option('enable_trace_fp', type: 'boolean', value: false, description:
>         'enable fast path trace points.')
>  option('tests', type: 'boolean', value: true, description:
> --
> 1.8.3.1
> 


  reply	other threads:[~2023-02-09  8:05 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-12 21:26 [PATCH] eal: abstract compiler atomics Tyler Retzlaff
2023-01-12 21:26 ` [PATCH] eal: introduce atomics abstraction Tyler Retzlaff
2023-01-31 22:42   ` Thomas Monjalon
2023-02-01  1:07     ` Honnappa Nagarahalli
2023-02-01  8:09       ` Morten Brørup
2023-02-01 21:41       ` Tyler Retzlaff
2023-02-02  8:43         ` Morten Brørup
2023-02-02 19:00           ` Tyler Retzlaff
2023-02-02 20:44             ` Morten Brørup
2023-02-03 13:56               ` Bruce Richardson
2023-02-03 14:25                 ` Morten Brørup
2023-02-03 12:19             ` Bruce Richardson
2023-02-03 20:49               ` Tyler Retzlaff
2023-02-07 15:16                 ` Morten Brørup
2023-02-07 21:58                   ` Tyler Retzlaff
2023-02-07 23:34         ` Honnappa Nagarahalli
2023-02-08  1:20           ` Tyler Retzlaff
2023-02-08  8:31             ` Morten Brørup
2023-02-08 16:35               ` Tyler Retzlaff
2023-02-09  0:16                 ` Honnappa Nagarahalli
2023-02-09  8:34                   ` Morten Brørup
2023-02-09 17:30                   ` Tyler Retzlaff
2023-02-10  5:30                     ` Honnappa Nagarahalli
2023-02-10 20:30                       ` Tyler Retzlaff
2023-02-13  5:04                         ` Honnappa Nagarahalli
2023-02-13 15:28                           ` Ben Magistro
2023-02-13 15:55                             ` Bruce Richardson
2023-02-13 16:46                               ` Ben Magistro
2023-02-13 17:49                                 ` Morten Brørup
2023-02-13 23:18                           ` Tyler Retzlaff
2023-01-31 21:33 ` [PATCH] eal: abstract compiler atomics Tyler Retzlaff
2023-02-08 21:43 ` [PATCH v2] " Tyler Retzlaff
2023-02-08 21:43   ` [PATCH v2] eal: introduce atomics abstraction Tyler Retzlaff
2023-02-09  8:05     ` Morten Brørup [this message]
2023-02-09 18:15       ` Tyler Retzlaff
2023-02-09 19:19         ` Morten Brørup
2023-02-09 22:04           ` Tyler Retzlaff
2023-04-03 21:17       ` Mattias Rönnblom
2023-02-09  9:04     ` Bruce Richardson
2023-02-09 12:53       ` Ferruh Yigit
2023-02-09 17:40         ` Tyler Retzlaff
2023-02-09 22:13           ` Ferruh Yigit
2023-02-10  0:36             ` Tyler Retzlaff
2023-02-09 17:38       ` Tyler Retzlaff
2023-04-03 21:32         ` Mattias Rönnblom
2023-04-03 21:11     ` Mattias Rönnblom
2023-04-03 21:25       ` Honnappa Nagarahalli
2023-04-04  2:24       ` Tyler Retzlaff
2023-02-22 18:09   ` [PATCH v2] eal: abstract compiler atomics Tyler Retzlaff
2023-02-22 20:07     ` Honnappa Nagarahalli
2023-02-23 19:11       ` Tyler Retzlaff

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=98CBD80474FA8B44BF855DF32C47DC35D87718@smartserver.smartshare.dk \
    --to=mb@smartsharesystems.com \
    --cc=Honnappa.Nagarahalli@arm.com \
    --cc=bruce.richardson@intel.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=roretzla@linux.microsoft.com \
    --cc=thomas@monjalon.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).