From patchwork Tue Jul 7 10:10:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Phil Yang X-Patchwork-Id: 73418 X-Patchwork-Delegate: david.marchand@redhat.com Return-Path: X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id D882AA00BE; Tue, 7 Jul 2020 12:10:56 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 17FAE1DD83; Tue, 7 Jul 2020 12:10:56 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id 824C21D567 for ; Tue, 7 Jul 2020 12:10:54 +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 E901BC0A; Tue, 7 Jul 2020 03:10:53 -0700 (PDT) Received: from phil-VirtualBox.shanghai.arm.com (phil-VirtualBox.shanghai.arm.com [10.169.109.153]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8CF7C3F71E; Tue, 7 Jul 2020 03:10:51 -0700 (PDT) From: Phil Yang To: david.marchand@redhat.com, dev@dpdk.org Cc: drc@linux.vnet.ibm.com, Honnappa.Nagarahalli@arm.com, olivier.matz@6wind.com, ruifeng.wang@arm.com, nd@arm.com Date: Tue, 7 Jul 2020 18:10:33 +0800 Message-Id: <1594116633-14554-1-git-send-email-phil.yang@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1591871178-12542-1-git-send-email-phil.yang@arm.com> References: <1591871178-12542-1-git-send-email-phil.yang@arm.com> Subject: [dpdk-dev] [PATCH v2] mbuf: use C11 atomics for refcnt operations 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" Use C11 atomics with explicit ordering instead of rte_atomic ops which enforce unnecessary barriers on aarch64. Signed-off-by: Phil Yang Reviewed-by: Ruifeng Wang --- v2: Fix ABI issue: revert the rte_mbuf_ext_shared_info struct refcnt field to refcnt_atomic. lib/librte_mbuf/rte_mbuf.c | 1 - lib/librte_mbuf/rte_mbuf.h | 19 ++++++++++--------- lib/librte_mbuf/rte_mbuf_core.h | 11 +++-------- 3 files changed, 13 insertions(+), 18 deletions(-) diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c index ae91ae2..8a456e5 100644 --- a/lib/librte_mbuf/rte_mbuf.c +++ b/lib/librte_mbuf/rte_mbuf.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include #include diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index f8e492e..4a7a98c 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -37,7 +37,6 @@ #include #include #include -#include #include #include #include @@ -365,7 +364,7 @@ rte_pktmbuf_priv_flags(struct rte_mempool *mp) static inline uint16_t rte_mbuf_refcnt_read(const struct rte_mbuf *m) { - return (uint16_t)(rte_atomic16_read(&m->refcnt_atomic)); + return __atomic_load_n(&m->refcnt, __ATOMIC_RELAXED); } /** @@ -378,14 +377,15 @@ rte_mbuf_refcnt_read(const struct rte_mbuf *m) static inline void rte_mbuf_refcnt_set(struct rte_mbuf *m, uint16_t new_value) { - rte_atomic16_set(&m->refcnt_atomic, (int16_t)new_value); + __atomic_store_n(&m->refcnt, new_value, __ATOMIC_RELAXED); } /* internal */ static inline uint16_t __rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value) { - return (uint16_t)(rte_atomic16_add_return(&m->refcnt_atomic, value)); + return (uint16_t)(__atomic_add_fetch((int16_t *)&m->refcnt, value, + __ATOMIC_ACQ_REL)); } /** @@ -466,7 +466,7 @@ rte_mbuf_refcnt_set(struct rte_mbuf *m, uint16_t new_value) static inline uint16_t rte_mbuf_ext_refcnt_read(const struct rte_mbuf_ext_shared_info *shinfo) { - return (uint16_t)(rte_atomic16_read(&shinfo->refcnt_atomic)); + return __atomic_load_n(&shinfo->refcnt_atomic, __ATOMIC_RELAXED); } /** @@ -481,7 +481,7 @@ static inline void rte_mbuf_ext_refcnt_set(struct rte_mbuf_ext_shared_info *shinfo, uint16_t new_value) { - rte_atomic16_set(&shinfo->refcnt_atomic, (int16_t)new_value); + __atomic_store_n(&shinfo->refcnt_atomic, new_value, __ATOMIC_RELAXED); } /** @@ -505,7 +505,8 @@ rte_mbuf_ext_refcnt_update(struct rte_mbuf_ext_shared_info *shinfo, return (uint16_t)value; } - return (uint16_t)rte_atomic16_add_return(&shinfo->refcnt_atomic, value); + return (uint16_t)(__atomic_add_fetch((int16_t *)&shinfo->refcnt_atomic, + value, __ATOMIC_ACQ_REL)); } /** Mbuf prefetch */ @@ -1304,8 +1305,8 @@ static inline int __rte_pktmbuf_pinned_extbuf_decref(struct rte_mbuf *m) * Direct usage of add primitive to avoid * duplication of comparing with one. */ - if (likely(rte_atomic16_add_return - (&shinfo->refcnt_atomic, -1))) + if (likely(__atomic_add_fetch((int *)&shinfo->refcnt_atomic, -1, + __ATOMIC_ACQ_REL))) return 1; /* Reinitialize counter before mbuf freeing. */ diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h index 16600f1..806313a 100644 --- a/lib/librte_mbuf/rte_mbuf_core.h +++ b/lib/librte_mbuf/rte_mbuf_core.h @@ -18,7 +18,6 @@ #include #include -#include #ifdef __cplusplus extern "C" { @@ -495,12 +494,8 @@ struct rte_mbuf { * or non-atomic) is controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC * config option. */ - RTE_STD_C11 - union { - rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */ - /** Non-atomically accessed refcnt */ - uint16_t refcnt; - }; + uint16_t refcnt; + uint16_t nb_segs; /**< Number of segments. */ /** Input port (16 bits to support more than 256 virtual ports). @@ -679,7 +674,7 @@ typedef void (*rte_mbuf_extbuf_free_callback_t)(void *addr, void *opaque); struct rte_mbuf_ext_shared_info { rte_mbuf_extbuf_free_callback_t free_cb; /**< Free callback function */ void *fcb_opaque; /**< Free callback argument */ - rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */ + uint16_t refcnt_atomic; /**< Atomically accessed refcnt */ }; /**< Maximum number of nb_segs allowed. */