From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from proxy.6wind.com (host.76.145.23.62.rev.coltfrance.com [62.23.145.76]) by dpdk.org (Postfix) with ESMTP id 2305C199B6 for ; Fri, 8 Dec 2017 16:47:06 +0100 (CET) Received: from glumotte.dev.6wind.com (unknown [10.16.0.195]) by proxy.6wind.com (Postfix) with ESMTP id EB7A21105FA; Fri, 8 Dec 2017 16:38:58 +0100 (CET) From: Olivier Matz To: dev@dpdk.org, hhaim@cisco.com Cc: matvejchikov@gmail.com, konstantin.ananyev@intel.com Date: Fri, 8 Dec 2017 16:46:51 +0100 Message-Id: <20171208154651.16546-1-olivier.matz@6wind.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171115091413.27119-1-hhaim@cisco.com> References: <20171115091413.27119-1-hhaim@cisco.com> Subject: [dpdk-dev] [PATCH v4] mbuf: fix mbuf free performance with non atomic refcnt 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: , X-List-Received-Date: Fri, 08 Dec 2017 15:47:07 -0000 When RTE_MBUF_REFCNT_ATOMIC=n, the decrement of the mbuf reference counter uses an atomic operation. This is not necessary and impacts the performance (seen with TRex traffic generator). We cannot replace rte_atomic16_add_return() by rte_mbuf_refcnt_update() because it would add an additional check. Solves this by introducing __rte_mbuf_refcnt_update(), which updates the reference counter without doing anything else. Fixes: 8f094a9ac5d7 ("mbuf: set mbuf fields while in pool") Suggested-by: Hanoch Haim Signed-off-by: Olivier Matz --- Hanoh, The following patch implements what was discussed in the thread. Are you ok with it? Thanks, Olivier lib/librte_mbuf/rte_mbuf.h | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index ce8a05ddf..dd08cb72b 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -764,6 +764,13 @@ rte_mbuf_refcnt_set(struct rte_mbuf *m, uint16_t new_value) rte_atomic16_set(&m->refcnt_atomic, new_value); } +/* 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)); +} + /** * Adds given value to an mbuf's refcnt and returns its new value. * @param m @@ -788,19 +795,26 @@ rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value) return 1 + value; } - return (uint16_t)(rte_atomic16_add_return(&m->refcnt_atomic, value)); + return __rte_mbuf_refcnt_update(m, value); } #else /* ! RTE_MBUF_REFCNT_ATOMIC */ +/* internal */ +static inline uint16_t +__rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value) +{ + m->refcnt = (uint16_t)(m->refcnt + value); + return m->refcnt; +} + /** * Adds given value to an mbuf's refcnt and returns its new value. */ static inline uint16_t rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value) { - m->refcnt = (uint16_t)(m->refcnt + value); - return m->refcnt; + return __rte_mbuf_refcnt_update(m, value); } /** @@ -1364,8 +1378,7 @@ rte_pktmbuf_prefree_seg(struct rte_mbuf *m) return m; - } else if (rte_atomic16_add_return(&m->refcnt_atomic, -1) == 0) { - + } else if (__rte_mbuf_refcnt_update(m, -1) == 0) { if (RTE_MBUF_INDIRECT(m)) rte_pktmbuf_detach(m); -- 2.11.0