From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124])
	by inbox.dpdk.org (Postfix) with ESMTP id 9E2DAA09E4;
	Fri, 29 Jan 2021 10:45:36 +0100 (CET)
Received: from [217.70.189.124] (localhost [127.0.0.1])
	by mails.dpdk.org (Postfix) with ESMTP id 39479240151;
	Fri, 29 Jan 2021 10:45:31 +0100 (CET)
Received: from mx.quacker.org (mx.quacker.org [129.97.75.228])
 by mails.dpdk.org (Postfix) with ESMTP id 2707E1410B3
 for <dev@dpdk.org>; Thu, 28 Jan 2021 05:07:09 +0100 (CET)
Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon)
 with ESMTPSA id 9807B326BB8A
 for <dev@dpdk.org>; Wed, 27 Jan 2021 23:07:07 -0500 (EST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quacker.org; s=dkim;
 t=1611806827; h=from:subject:date:message-id:to:mime-version:content-type;
 bh=c4x8NUB6CP4muiVcStz1k50JBGk34QL5aMZNytkNLFk=;
 b=g7XDQVoIJnvpD+sJZxwUsnL++v+re8vXwy6jy/QvLUojZKthtuRwlEl8aigL1hHPEmH4SE
 ry9dLIAL2aUqAooOPEbVWuposWkSLbLqhWKPmgzHEZSUwCWRyBENK523MB1mW0CXmud6wW
 AnOI4dBgknz0oYrnlPSREprIyXVMFYWXIJK1xOyUzHoSO39VyCnlRBCHKgvo6sN+VjvUkr
 FmVo/x0H7RJIZIUr9pZ6lwlph8uH1z0l7RrBHlKA/UP/hOqS5OQZtowfLmHbg/Q/oOSYVG
 Y2u+3ZhAaVXrgIFuOciUOFfOdkpDNmEB4z5Z22Otpxz1ykckTUJjN9ODMSljaQ==
MIME-Version: 1.0
Date: Thu, 28 Jan 2021 04:07:07 +0000
From: "Oscar Zhao" <oz@quacker.org>
Message-ID: <f030640f01e2c3dca2cb1bea3e45ae81@quacker.org>
To: dev@dpdk.org
X-Last-TLS-Session-Version: TLSv1.2
X-Mailman-Approved-At: Fri, 29 Jan 2021 10:45:28 +0100
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
X-Content-Filtered-By: Mailman/MimeDel 2.1.29
Subject: [dpdk-dev] Feature Discussion: CPU topology detection on FreeBSD
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

Hello dpdk devs,=0A=0AI would like to discuss the feasibility of implemen=
ting CPU topology detection on FreeBSD. Currently both eal_cpu_core_id() =
and eal_cpu_socket_id() in rte_eal library always return 0 on FreeBSD, ma=
king NUMA-aware development impossible without resorting to external libr=
aries or system APIs.=0A=0AThe CPU topology information is available via =
sysct kern.sched.topology_spec. The only issue is that the return value i=
s an XML formatted object (see https://forums.freebsd.org/threads/number-=
of-cpus-and-cores.41299/). (https://forums.freebsd.org/threads/number-of-=
cpus-and-cores.41299/) I'm not sure how feasible it is to parse XML insid=
e DPDK.=0A=0AOn a side note, obtaining the physical NUMA node id of a cor=
e is easy - sysctl dev.cpu.[cpu#].%domain returns the corresponding node =
id but I have yet found a straightforward way to detect hyperthreads besi=
des the XML thing.=0A=0AOscar