From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) by dpdk.org (Postfix) with ESMTP id 032262082 for ; Wed, 8 May 2019 22:30:04 +0200 (CEST) Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id 8D6E740023 for ; Wed, 8 May 2019 22:30:03 +0200 (CEST) Received: by mail.lysator.liu.se (Postfix, from userid 1004) id 76F1740022; Wed, 8 May 2019 22:30:03 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on bernadotte.lysator.liu.se X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=ALL_TRUSTED,AWL autolearn=disabled version=3.4.1 X-Spam-Score: -0.9 Received: from [192.168.1.59] (host-90-232-127-248.mobileonline.telia.com [90.232.127.248]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id 9C2CF40021; Wed, 8 May 2019 22:30:01 +0200 (CEST) To: Stephen Hemminger Cc: dev@dpdk.org, nhorman@tuxdriver.com, "Richardson, Bruce" References: <20190424123320.19610-1-mattias.ronnblom@ericsson.com> <20190424123320.19610-2-mattias.ronnblom@ericsson.com> <20190508131239.07e06092@xps13> From: =?UTF-8?Q?Mattias_R=c3=b6nnblom?= Message-ID: <576fb266-0163-9c4c-261c-2ce3261d7258@ericsson.com> Date: Wed, 8 May 2019 22:30:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190508131239.07e06092@xps13> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP Subject: Re: [dpdk-dev] [RFC v3 1/2] eal: replace libc-based random number generation with LFSR 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: Wed, 08 May 2019 20:30:04 -0000 On 2019-05-08 22:12, Stephen Hemminger wrote: > On Wed, 24 Apr 2019 14:33:19 +0200 > Mattias Rönnblom wrote: > >> diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c >> index 161399619..d6bf0e89e 100644 >> --- a/lib/librte_eal/linux/eal/eal.c >> +++ b/lib/librte_eal/linux/eal/eal.c >> @@ -1083,8 +1083,6 @@ rte_eal_init(int argc, char **argv) >> #endif >> } >> >> - rte_srand(rte_rdtsc()); > > The current model of seeding with TSC will have problems at scale. > If a whole rack of machines reboots at the same time because of power cycle, > it would not be surprising if several had the same TSC value. > > A better solution would be to use the get_random() system call to get > seed, the kernel can get entropy from more sources. > Sounds reasonable. What version of FreeBSD is DPDK supposed to support? getrandom(2) (and its cousin getentropy(3)) seem not be available until FreeBSD 12. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 09BECA0096 for ; Wed, 8 May 2019 22:30:05 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id B67D137A2; Wed, 8 May 2019 22:30:04 +0200 (CEST) Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) by dpdk.org (Postfix) with ESMTP id 032262082 for ; Wed, 8 May 2019 22:30:04 +0200 (CEST) Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id 8D6E740023 for ; Wed, 8 May 2019 22:30:03 +0200 (CEST) Received: by mail.lysator.liu.se (Postfix, from userid 1004) id 76F1740022; Wed, 8 May 2019 22:30:03 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on bernadotte.lysator.liu.se X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=ALL_TRUSTED,AWL autolearn=disabled version=3.4.1 X-Spam-Score: -0.9 Received: from [192.168.1.59] (host-90-232-127-248.mobileonline.telia.com [90.232.127.248]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id 9C2CF40021; Wed, 8 May 2019 22:30:01 +0200 (CEST) To: Stephen Hemminger Cc: dev@dpdk.org, nhorman@tuxdriver.com, "Richardson, Bruce" References: <20190424123320.19610-1-mattias.ronnblom@ericsson.com> <20190424123320.19610-2-mattias.ronnblom@ericsson.com> <20190508131239.07e06092@xps13> From: =?UTF-8?Q?Mattias_R=c3=b6nnblom?= Message-ID: <576fb266-0163-9c4c-261c-2ce3261d7258@ericsson.com> Date: Wed, 8 May 2019 22:30:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190508131239.07e06092@xps13> Content-Type: text/plain; charset="UTF-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP Subject: Re: [dpdk-dev] [RFC v3 1/2] eal: replace libc-based random number generation with LFSR 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190508203000.3gt9xu3s2vmGKSt8IwmeXKQjqXy-3jToF_GuP6IfSas@z> On 2019-05-08 22:12, Stephen Hemminger wrote: > On Wed, 24 Apr 2019 14:33:19 +0200 > Mattias Rönnblom wrote: > >> diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c >> index 161399619..d6bf0e89e 100644 >> --- a/lib/librte_eal/linux/eal/eal.c >> +++ b/lib/librte_eal/linux/eal/eal.c >> @@ -1083,8 +1083,6 @@ rte_eal_init(int argc, char **argv) >> #endif >> } >> >> - rte_srand(rte_rdtsc()); > > The current model of seeding with TSC will have problems at scale. > If a whole rack of machines reboots at the same time because of power cycle, > it would not be surprising if several had the same TSC value. > > A better solution would be to use the get_random() system call to get > seed, the kernel can get entropy from more sources. > Sounds reasonable. What version of FreeBSD is DPDK supposed to support? getrandom(2) (and its cousin getentropy(3)) seem not be available until FreeBSD 12.