From patchwork Thu Jul 9 10:10:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Phil Yang X-Patchwork-Id: 73632 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 C4A73A0529; Thu, 9 Jul 2020 12:11:14 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 1EDD41DA27; Thu, 9 Jul 2020 12:11:14 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id 4DB8F1DA1E for ; Thu, 9 Jul 2020 12:11:13 +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 6AFAE31B; Thu, 9 Jul 2020 03:11:12 -0700 (PDT) Received: from phil-VirtualBox.arm.com (A010647.Arm.com [10.170.226.139]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B50AF3F887; Thu, 9 Jul 2020 03:11:09 -0700 (PDT) From: Phil Yang To: olivier.matz@6wind.com, dev@dpdk.org Cc: stephen@networkplumber.org, david.marchand@redhat.com, drc@linux.vnet.ibm.com, Honnappa.Nagarahalli@arm.com, Ruifeng.Wang@arm.com, nd@arm.com Date: Thu, 9 Jul 2020 18:10:42 +0800 Message-Id: <1594289442-18594-1-git-send-email-phil.yang@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1594116633-14554-1-git-send-email-phil.yang@arm.com> References: <1594116633-14554-1-git-send-email-phil.yang@arm.com> Subject: [dpdk-dev] [PATCH v3] mbuf: use C11 atomic built-ins 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 atomic built-ins with explicit ordering instead of rte_atomic ops which enforce unnecessary barriers on aarch64. Signed-off-by: Phil Yang Reviewed-by: Ruifeng Wang --- v3: 1.Fix ABI breakage. 2.Simplify data type cast. 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 | 2 +- 3 files changed, 11 insertions(+), 11 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..c1c0956 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 __atomic_add_fetch(&m->refcnt, (uint16_t)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 __atomic_add_fetch(&shinfo->refcnt_atomic, (uint16_t)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(&shinfo->refcnt_atomic, (uint16_t)-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..d65d1c8 100644 --- a/lib/librte_mbuf/rte_mbuf_core.h +++ b/lib/librte_mbuf/rte_mbuf_core.h @@ -679,7 +679,7 @@ 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. */