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From: Bruce Richardson <bruce.richardson@intel.com>
To: Oscar Zhao <oz@quacker.org>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] Feature Discussion: CPU topology detection on FreeBSD
Date: Fri, 29 Jan 2021 10:05:37 +0000	[thread overview]
Message-ID: <20210129100537.GB929@bricha3-MOBL.ger.corp.intel.com> (raw)
In-Reply-To: <f030640f01e2c3dca2cb1bea3e45ae81@quacker.org>

On Thu, Jan 28, 2021 at 04:07:07AM +0000, Oscar Zhao wrote:
> Hello dpdk devs,
> 
> I would like to discuss the feasibility of implementing 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, making NUMA-aware development impossible without resorting to external libraries or system APIs.
> 
> The CPU topology information is available via sysct kern.sched.topology_spec. The only issue is that the return value is 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 inside DPDK.
> 
> On a side note, obtaining the physical NUMA node id of a core is easy - sysctl dev.cpu.[cpu#].%domain returns the corresponding node id but I have yet found a straightforward way to detect hyperthreads besides the XML thing.
> 
> Oscar

Even adding in the numa node information would be a welcome start.

  reply	other threads:[~2021-01-29 10:05 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-28  4:07 Oscar Zhao
2021-01-29 10:05 ` Bruce Richardson [this message]
2021-01-29 12:52   ` Burakov, Anatoly
2021-01-29 13:45     ` Bruce Richardson
2021-02-10 16:01       ` Burakov, Anatoly
2021-01-29 22:24     ` Oscar Zhao

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