From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.lttng.org (lists.lttng.org [167.114.26.123]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CF1E4EB64DC for ; Thu, 29 Jun 2023 16:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.lttng.org; s=default; t=1688057343; 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=Ivpdy9OKalSPCTsGztYNI/rp9w3zQZGyG3wYKxzKBqXYhrEud8oNgQWzk72FAK7CP dODgcozyaV3xciXiC/+FZVxuFMGLWbs3CiLNiTg7xHMr34eZXMlXQH7pAZIU9SNN+A cmh4r3xDiB48fEN+WQABNgK2ZRPXAsV5OmDKsVW4iL+sHwN9agb7x75DtDkN8nT0KF loYCzCreXabh32kIwQg/qyepGzk+gGZP6hdT0092qg5vFd3tlcwrvxhKEQUKXD5IIg noriA4QKRxJXH5wRHDWiJLOEhDsU3E+my3Op64BFzjWCz1liJ8Xj0wa0TZAFbSNB29 bXIdO9C8IYHMg== Received: from lists-lttng01.efficios.com (localhost [IPv6:::1]) by lists.lttng.org (Postfix) with ESMTP id 4QsPYB5Clhz22ST; 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