From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id 9034B1B5D9 for ; Tue, 17 Oct 2017 23:24:14 +0200 (CEST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 39E7F20C45; Tue, 17 Oct 2017 17:24:14 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute1.internal (MEProxy); Tue, 17 Oct 2017 17:24:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=mesmtp; bh=WmVd6fu21lc5upWBOuNaRSj7Ni kjM5xMSDPXokXnoZM=; b=fW6b155ttEUCtdjwvJUHXJfoqqJResGI9WA8rYT8i9 EjqKnQCl10gP9a2IPkaFe6cfy74w4Uj/HvhtOAGyf34np16p8EzvOeg6ttEGaXF2 wBFMs+ok/Mi6g4dAfvDzrsdQEe8HBqCTAWhdFVZytgPvkgunjI19oBVA/ogogDVc w= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=WmVd6f u21lc5upWBOuNaRSj7NikjM5xMSDPXokXnoZM=; b=iSUwZEOcOMa+7Z56x9EP3l omeh7aOLu3qNRpvE7QSpiHgLOJM+YnMWXFP6GnSwphZXJNUaBu7o//uDj2R+uUal /F2COeI/G1I9E/v0c3C8iOXoWY5ds5IM1cGYWHuSn8kzx0hyZJjTlupgIRApjjOu xLxBqp+0m2nwtsHbAJfxR/ZxwxdIArKRQDP1x6ztCtqtNQMbRtxI1rbVxHayTOdW bZYoOtAIz+eaDQ0qxUEvlHA8pkxYstQjYPjLd+BJXce8YAYULNGGreHtndyaTOof aQUlJynK4jgEyQoVGzlsSfx+dKmBT+9AXCXlMwd2cyk7lXkBbVIaEWGVvm+I3inw == X-ME-Sender: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id DD968245E3; Tue, 17 Oct 2017 17:24:13 -0400 (EDT) From: Thomas Monjalon To: Xiaoyun Li , konstantin.ananyev@intel.com, bruce.richardson@intel.com Cc: dev@dpdk.org, wenzhuo.lu@intel.com, helin.zhang@intel.com, ophirmu@mellanox.com Date: Tue, 17 Oct 2017 23:24:12 +0200 Message-ID: <4482530.zMd2RtzCvC@xps> In-Reply-To: <1507885309-165144-2-git-send-email-xiaoyun.li@intel.com> References: <1507206794-79941-1-git-send-email-xiaoyun.li@intel.com> <1507885309-165144-1-git-send-email-xiaoyun.li@intel.com> <1507885309-165144-2-git-send-email-xiaoyun.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over memcpy 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: Tue, 17 Oct 2017 21:24:14 -0000 Hi, 13/10/2017 11:01, Xiaoyun Li: > This patch dynamically selects functions of memcpy at run-time based > on CPU flags that current machine supports. This patch uses function > pointers which are bind to the relative functions at constrctor time. > In addition, AVX512 instructions set would be compiled only if users > config it enabled and the compiler supports it. > > Signed-off-by: Xiaoyun Li > --- Keeping only the major changes of the patch for later discussions: [...] > static inline void * > rte_memcpy(void *dst, const void *src, size_t n) > { > - if (!(((uintptr_t)dst | (uintptr_t)src) & ALIGNMENT_MASK)) > - return rte_memcpy_aligned(dst, src, n); > + if (n <= RTE_X86_MEMCPY_THRESH) > + return rte_memcpy_internal(dst, src, n); > else > - return rte_memcpy_generic(dst, src, n); > + return (*rte_memcpy_ptr)(dst, src, n); > } [...] > +static inline void * > +rte_memcpy_internal(void *dst, const void *src, size_t n) > +{ > + if (!(((uintptr_t)dst | (uintptr_t)src) & ALIGNMENT_MASK)) > + return rte_memcpy_aligned(dst, src, n); > + else > + return rte_memcpy_generic(dst, src, n); > +} The significant change of this patch is to call a function pointer for packet size > 128 (RTE_X86_MEMCPY_THRESH). Please could you provide some benchmark numbers? >>From a test done at Mellanox, there might be a performance degradation of about 15% in testpmd txonly with AVX2. Is there someone else seeing a performance degradation?