From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id 5OaNGQG2nWTtSBEAWB0awg (envelope-from ) for ; Thu, 29 Jun 2023 12:49:05 -0400 Authentication-Results: simark.ca; dkim=pass (2048-bit key; unprotected) header.d=lists.lttng.org header.i=@lists.lttng.org header.a=rsa-sha256 header.s=default header.b=glFcfCBz; dkim-atps=neutral Received: by simark.ca (Postfix, from userid 112) id 5A9221E0BB; Thu, 29 Jun 2023 12:49:05 -0400 (EDT) Received: from lists.lttng.org (lists.lttng.org [167.114.26.123]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 0E6811E0AC for ; Thu, 29 Jun 2023 12:49:03 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.lttng.org; s=default; t=1688057342; bh=9+AwGk1TL8khZEVmIt5VRpCFSrCXpPhRL3HzW8LpZSc=; h=To:In-Reply-To:References:Date:Subject:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=glFcfCBz9x+3EAIdbV5aPcDwZG9pcUq0o/G9qDtQ7FvJzixO2fDaQK6IEU3VjJmbF Je+njLGZu6vSiWYpa9IsUVUZQY/tQiccwcyk5c9dke0I/tluXAjyqI1LJh209g8wIF IKhVR6gT8W+8Pn8hDC60yBF6Ot9na3yC4Bx7DtUUJsiwwcOr/nNahjUBejf6ytnHQi l3Cvcz3ap/IQ3Dfxa70ECS130eUM4CVyp4uKEu0hC5S1AtWq+tV98w7nr3rY36MO3S Zc23MFVXpzFMQHJ8s3C1ZyJ6p8nnLq5YwVDjnSXJbYixV544lEGgAMYB6RvFNkDl+3 XB7xRXfqcK7Qg== Received: from lists-lttng01.efficios.com (localhost [IPv6:::1]) by lists.lttng.org (Postfix) with ESMTP id 4QsPYB3Bw6z22Q3; Thu, 29 Jun 2023 12:49:02 -0400 (EDT) Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) by lists.lttng.org (Postfix) with ESMTPS id 4QsPY93091z223w for ; Thu, 29 Jun 2023 12:49:01 -0400 (EDT) Received: from localhost (modemcable094.169-200-24.mc.videotron.ca [24.200.169.94]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4QsPY839LCz19Rn; Thu, 29 Jun 2023 12:49:00 -0400 (EDT) To: paulmck@kernel.org In-Reply-To: Organization: EfficiOS References: <20230515201718.9809-1-odion@efficios.com> <20230607185359.8125-6-odion@efficios.com> Date: Thu, 29 Jun 2023 12:49:00 -0400 Message-ID: <87bkgyjjsz.fsf@laura> MIME-Version: 1.0 Subject: Re: [lttng-dev] [PATCH v2 05/12] urcu/uatomic: Add CMM memory model X-BeenThere: lttng-dev@lists.lttng.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: LTTng development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Olivier Dion via lttng-dev Reply-To: Olivier Dion Cc: Tony Finch , lttng-dev@lists.lttng.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" On Wed, 21 Jun 2023, "Paul E. McKenney" wrote: > On Wed, Jun 07, 2023 at 02:53:52PM -0400, Olivier Dion wrote: >> -#ifdef __URCU_DEREFERENCE_USE_ATOMIC_CONSUME >> -# define _rcu_dereference(p) __extension__ ({ \ >> - __typeof__(__extension__ ({ \ >> - __typeof__(p) __attribute__((unused)) _________p0 = { 0 }; \ >> - _________p0; \ >> - })) _________p1; \ >> - __atomic_load(&(p), &_________p1, __ATOMIC_CONSUME); \ > > There is talk of getting rid of memory_order_consume. But for the moment, > it is what there is. Another alternative is to use a volatile load, > similar to old-style CMM_LOAD_SHARED() or in-kernel READ_ONCE(). I think we can stick to __ATOMIC_CONSUME for now. Hopefully getting rid of it means it will be an alias for __ATOMIC_ACQUIRE for ever. -- Olivier Dion EfficiOS Inc. https://www.efficios.com _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev