From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerin Jacob Subject: [PATCH] mbuf: reduce pktmbuf init cycles Date: Mon, 5 Jun 2017 22:08:07 +0530 Message-ID: <20170605163807.31941-1-jerin.jacob@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain Cc: olivier.matz@6wind.com, Jerin Jacob To: dev@dpdk.org Return-path: Received: from NAM02-CY1-obe.outbound.protection.outlook.com (mail-cys01nam02on0066.outbound.protection.outlook.com [104.47.37.66]) by dpdk.org (Postfix) with ESMTP id 9FD9F7CAC for ; Mon, 5 Jun 2017 18:38:33 +0200 (CEST) List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" There is no need for initializing the complete packet buffer with zero as the packet data area will be overwritten by the NIC Rx HW anyway. The testpmd configures the packet mempool with around 180k buffers with 2176B size. In existing scheme, the init routine needs to memset around ~370MB vs the proposed scheme requires only around ~44MB on 128B cache aligned system. Useful in running DPDK in HW simulators/emulators, where millions of cycles have an impact on boot time. Signed-off-by: Jerin Jacob --- lib/librte_mbuf/rte_mbuf.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c index 0e3e36a58..1d5ce7816 100644 --- a/lib/librte_mbuf/rte_mbuf.c +++ b/lib/librte_mbuf/rte_mbuf.c @@ -131,8 +131,7 @@ rte_pktmbuf_init(struct rte_mempool *mp, RTE_ASSERT(mp->elt_size >= mbuf_size); RTE_ASSERT(buf_len <= UINT16_MAX); - memset(m, 0, mp->elt_size); - + memset(m, 0, mbuf_size + RTE_PKTMBUF_HEADROOM); /* start of buffer is after mbuf structure and priv data */ m->priv_size = priv_size; m->buf_addr = (char *)m + mbuf_size; -- 2.13.0