From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id DEF1CA04BB; Fri, 11 Sep 2020 17:31:18 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id B3F961C0CF; Fri, 11 Sep 2020 17:31:18 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id 727461C0CD for ; Fri, 11 Sep 2020 17:31:17 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F29701063; Fri, 11 Sep 2020 08:31:16 -0700 (PDT) Received: from localhost.localdomain (unknown [10.57.10.210]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 55D653F73C; Fri, 11 Sep 2020 08:31:15 -0700 (PDT) From: Steven Lariau To: Gage Eads , Olivier Matz Cc: dev@dpdk.org, nd@arm.com, dharmik.thakkar@arm.com, Steven Lariau Date: Fri, 11 Sep 2020 16:29:34 +0100 Message-Id: <20200911152938.8019-2-steven.lariau@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200911152938.8019-1-steven.lariau@arm.com> References: <20200911152938.8019-1-steven.lariau@arm.com> Subject: [dpdk-dev] [PATCH 1/5] lib/stack: fix inconsistent weak / strong cas X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Fix cmpexchange usage of weak / strong. The generated code is the same on x86 and ARM (there is no weak cmpexchange), but the old usage was inconsistent. For push and pop update size, weak is used because cmpexchange is inside a loop. For pop update root, strong is used even though cmpexchange is inside a loop, because there may be a lot of operations to do in a loop iteration (locate the new head). Signed-off-by: Steven Lariau Reviewed-by: Dharmik Thakkar Reviewed-by: Ruifeng Wang --- lib/librte_stack/rte_stack_lf_c11.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/librte_stack/rte_stack_lf_c11.h b/lib/librte_stack/rte_stack_lf_c11.h index 999359f08..1e0ea0bef 100644 --- a/lib/librte_stack/rte_stack_lf_c11.h +++ b/lib/librte_stack/rte_stack_lf_c11.h @@ -96,7 +96,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list, /* len is updated on failure */ if (__atomic_compare_exchange_n(&list->len, &len, len - num, - 0, __ATOMIC_ACQUIRE, + 1, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) break; } @@ -149,7 +149,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list, (rte_int128_t *)&list->head, (rte_int128_t *)&old_head, (rte_int128_t *)&new_head, - 1, __ATOMIC_RELEASE, + 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED); } while (success == 0); -- 2.17.1