From: "Laszlo Ersek" <lersek@redhat.com>
To: devel@edk2.groups.io, tigerliu@zhaoxin.com
Subject: Re: [edk2-devel] MP Services Protocol : Support Hyper threading or not
Date: Mon, 22 Feb 2021 11:39:47 +0100 [thread overview]
Message-ID: <581d5952-32b2-56e3-30d5-7f7f24039fa0@redhat.com> (raw)
In-Reply-To: <03f9e675800143189bc59fab08865256@zhaoxin.com>
On 02/22/21 08:08, Tiger Liu(BJ-RD) wrote:
> Dear All:
> I have a question about MP Services Protocol.
> Does it support Hyper-threading technology?
>
> For example:
> A Quad-cores CPU(with HT feature support), actually it is equal to 8 logical cores.
> Take assumption 8 logical cores are all healthy and being enabled.
>
> So:
>
> 1. Will EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors()return total 8 logical processor cores?
>
> 2. Will EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() make all 8 logical cores do some tasks simultaneously?
My understanding is "yes", to both questions. Most of the MP stuff deals
with "logical processors".
BTW, if you check the EFI_MP_SERVICES_GET_PROCESSOR_INFO prototype, it
outputs EFI_PROCESSOR_INFORMATION. The latter has the following fields:
EFI_CPU_PHYSICAL_LOCATION Location;
EXTENDED_PROCESSOR_INFORMATION ExtendedInformation;
The former gives you a package/core/thread identification for a
particular processor number. The latter (optionally) provides a 6-level
description (package / module / tile / die / core / thread). In each
information structure, "logical thread" is the finest granularity
information.
hth
Laszlo
next prev parent reply other threads:[~2021-02-22 10:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-22 7:08 [edk2-devel] MP Services Protocol : Support Hyper threading or not Tiger Liu(BJ-RD)
2021-02-22 10:39 ` Laszlo Ersek [this message]
2021-02-23 1:17 ` fanjianfeng
2021-02-23 17:29 ` Laszlo Ersek
-- strict thread matches above, loose matches on Subject: below --
2021-02-23 4:49 Tiger Liu(BJ-RD)
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