DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Mattias Rönnblom" <hofors@lysator.liu.se>
To: Tyler Retzlaff <roretzla@linux.microsoft.com>,
	Bruce Richardson <bruce.richardson@intel.com>
Cc: dev@dpdk.org, david.marchand@redhat.com, thomas@monjalon.net,
	mb@smartsharesystems.com, Honnappa.Nagarahalli@arm.com
Subject: Re: [PATCH v2] eal: introduce atomics abstraction
Date: Mon, 3 Apr 2023 23:32:50 +0200	[thread overview]
Message-ID: <4c7b5e51-51bd-fc88-b0b2-a952332d9f47@lysator.liu.se> (raw)
In-Reply-To: <20230209173804.GB21854@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>

On 2023-02-09 18:38, Tyler Retzlaff wrote:
> On Thu, Feb 09, 2023 at 09:04:16AM +0000, Bruce Richardson wrote:
>> On Wed, Feb 08, 2023 at 01:43:38PM -0800, Tyler Retzlaff wrote:
>>> 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>
>>> ---
>>>   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')
>>
>> Is there a reason for using gnu11 on gcc and clang, rather than limiting
>> ourselves to proper c11 support?
> 
> there is code using posix extensions, there are two ways to use them
> without emitting warnings.
> 
> 1. -std=gnu11 (to get C11 with GNU extensions)
> 
> -- or --
> 
> 2. -std=c11 and then in the source files consuming the C11 GNU
> extensions do some dance with various GNUC macros before including
> various stdxxx.h headers to enable the extensions for the translation
> unit.
> 
> i vaguely recall that if you try to do a test build with -std=c11 over
> the whole tree with meson --werror it will highlight the exact code i'm
> talking about.
> 
> selfishly i'd be happy to see (2) done and potentially eliminate the use
> of the extensions, but i didn't want to be disruptive as a part of this
> change.
> 

Some of the GNU extensions are useful, and have no equivalent in C11.

Statement expressions is one example that comes to mind.

I think you can get such code through GCC even with -std=c11, but not if 
combined with -pedantic.


  reply	other threads:[~2023-04-03 21:32 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
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 [this message]
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=4c7b5e51-51bd-fc88-b0b2-a952332d9f47@lysator.liu.se \
    --to=hofors@lysator.liu.se \
    --cc=Honnappa.Nagarahalli@arm.com \
    --cc=bruce.richardson@intel.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=mb@smartsharesystems.com \
    --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).