From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f42.google.com (mail-wm0-f42.google.com [74.125.82.42]) by dpdk.org (Postfix) with ESMTP id CDEEE39EA for ; Thu, 16 Feb 2017 16:16:12 +0100 (CET) Received: by mail-wm0-f42.google.com with SMTP id r141so17619055wmg.1 for ; Thu, 16 Feb 2017 07:16:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=5gh0l+DBOBES01l7dIukUN4Ik8aP47zUOdZwftlySyA=; b=r7mjUBzElQ5V1rIRpgX1X1i7wxEDvCWKm/LkEhNZpotiTI4wtoVGQmLKF0LgEfOt0c iTpZN9WSLeQ+8l9yQRi3+NvPSemruLKcpxRhltSuOEt6Jsed6Ohj5noj8qL7OX6cZZ3j DXCDp7TSBIq0tGvLk/TQ56mUHnfAFVBMx2A7Z+zkP0OViUKaT4/RIg1tsn5G0XD8FAxE fjaZ2QABQ3bGGg9ZU/JLZl4jGeH1LPVgu2yKXYK6KynQV1qb5W7fcC0GivJvK4pNS36K 96kh3eIt4OsMTkw8owNBZtZOSunevicO+p0Ad2SoFJyuU3YHeSzgiFvzcG2SE46UPeOx SwZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5gh0l+DBOBES01l7dIukUN4Ik8aP47zUOdZwftlySyA=; b=AhSXZFkhd4mE75vb65IJpqxIYSG0zUD+NpsPL04CBTCWMiFtpYEEYexcSEgu68l5NQ R+jPbTbVL9VpeUGifMa/h1+jOe5+7dZc6Rcd0eFeUM9EjeyAFczXdRsYEo5fuQ8HbHMu Hh9aw41IzmfKdOdnCobHJq2goWKE29NaphDY/kTiBJ0YFagxfBQd2W7Z73mDrOc1uA7V d/HsBKwlPpM++ciXih0s4tehjbOdAdZh96ZD3fcE55ps/LvdDlYz8K1LURuJvVUTTTif 6PglVaxjmWE9kDLR5tnZdTn9PQu2lbMh+Gz43YPnzcBw42JJMD+PLubIBQY1YFgMcsS9 08HA== X-Gm-Message-State: AMke39mkK0JfAML0p7QVCFfvJD1wmqKhpShWBIUxeTYkYVjlWJjttCxYVamVZSP7DC1pxF/t X-Received: by 10.28.165.196 with SMTP id o187mr12495240wme.6.1487258172505; Thu, 16 Feb 2017 07:16:12 -0800 (PST) Received: from platinum (2a01cb0c03c651000226b0fffeed02fc.ipv6.abo.wanadoo.fr. [2a01:cb0c:3c6:5100:226:b0ff:feed:2fc]) by smtp.gmail.com with ESMTPSA id t103sm9357017wrc.43.2017.02.16.07.16.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 16 Feb 2017 07:16:12 -0800 (PST) Date: Thu, 16 Feb 2017 16:16:08 +0100 From: Olivier Matz To: Thomas Monjalon Cc: konstantin.ananyev@intel.com, bruce.richardson@intel.com, dev@dpdk.org, Paul Emmerich , "Mike A. Polehn" Message-ID: <20170216161608.6715803c@platinum> In-Reply-To: <1666545.dgckzNb2Rl@xps13> References: <1431386118-2811-1-git-send-email-emmericp@net.in.tum.de> <6143149.O6nc0QL3DF@xps13> <55ACAB1B.2030508@6wind.com> <1666545.dgckzNb2Rl@xps13> X-Mailer: Claws Mail 3.14.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] prefetch second cacheline of mbufs on alloc 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: Thu, 16 Feb 2017 15:16:12 -0000 On Wed, 15 Feb 2017 09:44:35 +0100, Thomas Monjalon wrote: > Do we need to discuss again the prefetch calls inside DPDK > or can we definitely close this kind of request? > mbuf: http://dpdk.org/patch/4678/ > ethdev: http://dpdk.org/patch/8867/ > About the mbuf prefetch, I suggest the topic can be closed: The rte_pkt_mbuf_alloc() function is not necessarily called in a place where we will write the second cache line, so the prefetch is not always useful. Having prefetches in generic functions does not look to be a good idea, especially in that case, knowing it's easy to do it in the application. Olivier > > 2015-07-20 10:02, Olivier MATZ: > > Hi Thomas, > > > > > > On 07/20/2015 03:00 AM, Thomas Monjalon wrote: > > > Please Olivier, > > > What is the status of this patch? > > > > From what I remember, the last mail was a comment from Konstantin > > on another thread (but same topic): > > http://dpdk.org/ml/archives/dev/2015-May/017633.html > > > > > > Regards, > > Olivier > > > > > > > > > > 2015-05-12 01:15, Paul Emmerich: > > >> this improves the throughput of a simple tx-only application by > > >> 11% in the full-featured ixgbe tx path and by 14% in the simple > > >> tx path. --- > > >> lib/librte_mbuf/rte_mbuf.h | 1 + > > >> 1 file changed, 1 insertion(+) > > >> > > >> diff --git a/lib/librte_mbuf/rte_mbuf.h > > >> b/lib/librte_mbuf/rte_mbuf.h index ab6de67..f6895b4 100644 > > >> --- a/lib/librte_mbuf/rte_mbuf.h > > >> +++ b/lib/librte_mbuf/rte_mbuf.h > > >> @@ -538,6 +538,7 @@ static inline struct rte_mbuf > > >> *__rte_mbuf_raw_alloc(struct rte_mempool *mp) if > > >> (rte_mempool_get(mp, &mb) < 0) return NULL; > > >> m = (struct rte_mbuf *)mb; > > >> + rte_prefetch0(&m->cacheline1); > > >> RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(m) == 0); > > >> rte_mbuf_refcnt_set(m, 1); > > >> return (m); > > >> > > > > > > > >