From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124])
	by inbox.dpdk.org (Postfix) with ESMTP id 98B3641EC3;
	Fri, 17 Mar 2023 22:49:13 +0100 (CET)
Received: from mails.dpdk.org (localhost [127.0.0.1])
	by mails.dpdk.org (Postfix) with ESMTP id 4635C42FE8;
	Fri, 17 Mar 2023 22:49:13 +0100 (CET)
Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182])
 by mails.dpdk.org (Postfix) with ESMTP id 8B0B440DF6
 for <dev@dpdk.org>; Fri, 17 Mar 2023 22:49:11 +0100 (CET)
Received: by linux.microsoft.com (Postfix, from userid 1086)
 id C2DDE2057675; Fri, 17 Mar 2023 14:49:10 -0700 (PDT)
DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C2DDE2057675
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com;
 s=default; t=1679089750;
 bh=61PllOCKFo8ENFVjgdwJ3Bv2Pe+bZWkAgaxxgPTpUPA=;
 h=Date:From:To:Cc:Subject:References:In-Reply-To:From;
 b=TaX8PgiAGkw3BUeuc82wHZ2ifSVg+ajo7/BEHyNlgKrRX4xFDpiLQXMz8Sbi0c4q2
 0SjMn4KfbL8ZuRWQnCA2TcDwg/8OTXd5ctVdX188Ab8Wv2txEDgNni4yDLb94gyBxk
 xNYXjMBEqt+I90LrieGXg6EZTfhCAUTr7EKYA1/Q=
Date: Fri, 17 Mar 2023 14:49:10 -0700
From: Tyler Retzlaff <roretzla@linux.microsoft.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: dev@dpdk.org, Honnappa.Nagarahalli@arm.com, Ruifeng.Wang@arm.com,
 thomas@monjalon.net
Subject: Re: [PATCH 0/7] replace rte atomics with GCC builtin atomics
Message-ID: <20230317214910.GA31884@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
References: <1679084388-19267-1-git-send-email-roretzla@linux.microsoft.com>
 <20230317144226.2f26bad1@hermes.local>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230317144226.2f26bad1@hermes.local>
User-Agent: Mutt/1.5.21 (2010-09-15)
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org

On Fri, Mar 17, 2023 at 02:42:26PM -0700, Stephen Hemminger wrote:
> On Fri, 17 Mar 2023 13:19:41 -0700
> Tyler Retzlaff <roretzla@linux.microsoft.com> wrote:
> 
> > Replace the use of rte_atomic.h types and functions, instead use GCC
> > supplied C++11 memory model builtins.
> > 
> > This series covers the libraries and drivers that are built on Windows.
> > 
> > The code has be converted to use the __atomic builtins but there are
> > additional during conversion i notice that there may be some issues
> > that need to be addressed.
> 
> I don't think all these cmpset need to use SEQ_CST.
> Especially for the places where it is used a loop, might
> be more efficient with some of the other memory models.

i agree.

however, i'm not trying to improve the code with this change, just
decouple it from rte_atomics.h so trying my best to avoid any
unnecessary semantic change.

certainly if the maintainers of this code wish to weaken the ordering
where appropriate after the change is merged they can do so and handily
this change has enabled them to do so easily allowing them to test just
their change in isolation.