From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f178.google.com (mail-ie0-f178.google.com [209.85.223.178]) by dpdk.org (Postfix) with ESMTP id 7D54F6942 for ; Wed, 1 Apr 2015 04:17:55 +0200 (CEST) Received: by ierf6 with SMTP id f6so32060470ier.2 for ; Tue, 31 Mar 2015 19:17:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=MI8LhGpbBP1U2ltYj0+5Re/+xnOVFKGblZjB4P049Gk=; b=KsIkzg6XKc9DfVe7Us1PdAgHcxMCqx6V45PvqSBhpCKBOofYCPphUATzwfTLspCGHj 1QzuqWVSCXPl+gPirQBxN8uxkBk8o/HvBSQ3IkxUu84QaQ95sJs/bdnNOMUBVN77c0/p uZIWOzmJocjjWCM4zpmcRD8mA2S6vZ4hZF/BorJysfkWfYjCIfUPnL93+7ZIB6x7Fdgf k6iFtqc5mNGlVuZzD4shCZhRyAGP3mOOKA6se8wt9y09Ui66g+Qic7Hg9SYxJzjlt/2M J/BUdYJ1CypjmW/iG/1U0ZpXoUtb09OeOKwWKktIIOJ906Q1tSrUmV/WLcgLGGQuEfjF Q4Vg== X-Gm-Message-State: ALoCoQm6cHvX6+6i0EqiGnK1tfT8czZlR//yi1KRya4TXikIbp7MFics4TCebmk8Vf/5RZfV4Hrr MIME-Version: 1.0 X-Received: by 10.42.148.197 with SMTP id s5mr70982720icv.13.1427854674821; Tue, 31 Mar 2015 19:17:54 -0700 (PDT) Received: by 10.64.58.129 with HTTP; Tue, 31 Mar 2015 19:17:54 -0700 (PDT) In-Reply-To: <20150331015104.GA12702@neilslaptop.think-freely.org> References: <1426609081-47774-1-git-send-email-rsanford@akamai.com> <20150328003821.GA13992@mhcomputing.net> <20150331015104.GA12702@neilslaptop.think-freely.org> Date: Tue, 31 Mar 2015 19:17:54 -0700 Message-ID: From: Stephen Hemminger To: Neil Horman Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [RFC PATCH] eal: rte_rand yields only 62 random bits X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Apr 2015 02:17:55 -0000 Plus the driver and sched uses really only need of few bits of crap random number. Probably simple BSD random (32 bits) is more than enough On Mon, Mar 30, 2015 at 6:51 PM, Neil Horman wrote: > On Mon, Mar 30, 2015 at 06:19:28PM -0400, Robert Sanford wrote: > > Yes, applications have many choices for PRNGs. But, we still need one > > internally for the following libs: PMDs (e1000, fm10k, i40e, ixgbe, > virtio, > > xenvirt), sched, and timer. > > > They can be updated to use the apropriate rng from an external library. > Neil > > > > > On Fri, Mar 27, 2015 at 8:03 PM, Stephen Hemminger < > > stephen@networkplumber.org> wrote: > > > I would argue remove rte_rand from DPDK. > > > > > > > > On Mon, Mar 30, 2015 at 1:28 AM, Stephen Hemminger < > > stephen@networkplumber.org> wrote: > > > > > if some one needs PRNG, th GNU scientific library has lots of them > > > > > > > https://www.gnu.org/software/gsl/manual/html_node/Random-number-generator-algorithms.html > > > > > > On Fri, Mar 27, 2015 at 5:38 PM, Matthew Hall > > > wrote: > > > > > > > On Fri, Mar 27, 2015 at 05:03:02PM -0700, Stephen Hemminger wrote: > > > > > I would argue remove rte_rand from DPDK. > > > > > > > > +1 > > > > > > > > To paraphrase Donald Knuth, "Random numbers should not be generated > > > [using > > > > a > > > > function coded] at random." > > > > > > > > It'd be better to fix libc, or considering that has a slow dev cycle > and > > > > platform compatibility limits, use some simple, semi-random, > > > > high-performance > > > > BSD licensed routine from a known-good library. > > > > > > > > Matthew. > > > > > > > > > >