From owner-dev-commits-src-branches@freebsd.org  Mon Feb  1 13:53:36 2021
Return-Path: <owner-dev-commits-src-branches@freebsd.org>
Delivered-To: dev-commits-src-branches@mailman.nyi.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1])
 by mailman.nyi.freebsd.org (Postfix) with ESMTP id 7158F52A5F4;
 Mon,  1 Feb 2021 13:53:36 +0000 (UTC) (envelope-from hps@selasky.org)
Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
 key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256)
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 4DTqD02DNyz3QlN;
 Mon,  1 Feb 2021 13:53:35 +0000 (UTC) (envelope-from hps@selasky.org)
Received: from hps2020.home.selasky.org (unknown [178.17.145.105])
 (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)
 key-exchange X25519 server-signature RSA-PSS (2048 bits))
 (No client certificate requested)
 by mail.turbocat.net (Postfix) with ESMTPSA id D438C26019D;
 Mon,  1 Feb 2021 14:53:34 +0100 (CET)
Subject: Re: git: fc301c224b27 - stable/13 - atomic: add stub
 atomic_load_consume_ptr
To: Mateusz Guzik <mjg@FreeBSD.org>, src-committers@FreeBSD.org,
 dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org
References: <202102011240.111CeiX9094867@gitrepo.freebsd.org>
From: Hans Petter Selasky <hps@selasky.org>
Message-ID: <84f152e1-b1ed-b331-ab45-261dd3996903@selasky.org>
Date: Mon, 1 Feb 2021 14:53:22 +0100
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101
 Thunderbird/78.5.0
MIME-Version: 1.0
In-Reply-To: <202102011240.111CeiX9094867@gitrepo.freebsd.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Rspamd-Queue-Id: 4DTqD02DNyz3QlN
X-Spamd-Bar: ----
Authentication-Results: mx1.freebsd.org;
	none
X-Spamd-Result: default: False [-4.00 / 15.00];
	 REPLY(-4.00)[]
X-BeenThere: dev-commits-src-branches@freebsd.org
X-Mailman-Version: 2.1.34
Precedence: list
List-Id: Commits to the stable branches of the FreeBSD src repository
 <dev-commits-src-branches.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/dev-commits-src-branches>, 
 <mailto:dev-commits-src-branches-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/dev-commits-src-branches/>
List-Post: <mailto:dev-commits-src-branches@freebsd.org>
List-Help: <mailto:dev-commits-src-branches-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/dev-commits-src-branches>, 
 <mailto:dev-commits-src-branches-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 01 Feb 2021 13:53:36 -0000

On 2/1/21 1:40 PM, Mateusz Guzik wrote:
> +/*
> + * Currently all architectures provide acquire and release fences on their own,
> + * but they don't provide consume. Kludge below allows relevant code to stop
> + * openly resorting to the stronger acquire fence, to be sorted out.
> + */
> +#define	atomic_load_consume_ptr(p)	\
> +    ((__typeof(*p)) atomic_load_acq_ptr((uintptr_t *)p))
> +

Are you missing:

CTASSERT(sizeof(*p) == sizeof(void *)) ????

--HPS