linux-api.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Len Brown <lenb@kernel.org>
To: Florian Weimer <fweimer@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>, Willy Tarreau <w@1wt.eu>,
	Andy Lutomirski <luto@kernel.org>,
	"Bae, Chang Seok" <chang.seok.bae@intel.com>,
	Dave Hansen <dave.hansen@intel.com>, X86 ML <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux API <linux-api@vger.kernel.org>,
	"libc-alpha@sourceware.org" <libc-alpha@sourceware.org>,
	Rich Felker <dalias@libc.org>, Kyle Huey <me@kylehuey.com>,
	Keno Fischer <keno@juliacomputing.com>,
	Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: Candidate Linux ABI for Intel AMX and hypothetical new related features
Date: Fri, 21 May 2021 12:29:39 -0400	[thread overview]
Message-ID: <CAJvTdK=suyVdH5U4WAdAmsJcnZbRx4tOot-Eu_SV4LSwLwP+zw@mail.gmail.com> (raw)
In-Reply-To: <87pmxpk7jo.fsf@oldenburg.str.redhat.com>

On Mon, May 17, 2021 at 5:56 AM Florian Weimer <fweimer@redhat.com> wrote:

> How expensive is checking XCR0 via XGETBV instead, on the AMX path?

XGETBV takes about the same number of cycles as RDTSC (ie. it is
relatively fast)

Len Brown, Intel Open Source Technology Center

  parent reply	other threads:[~2021-05-21 16:29 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210415044258.GA6318@zn.tnic>
     [not found] ` <20210415052938.GA2325@1wt.eu>
     [not found]   ` <20210415054713.GB6318@zn.tnic>
     [not found]     ` <CAJvTdKnjzAMh3N_c7KP3kA=e0LgYHgCANg44oJp3LcSm7dtbSQ@mail.gmail.com>
     [not found]       ` <20210419141454.GE9093@zn.tnic>
     [not found]         ` <CAJvTdK=p8mgO3xw9sRxu0c7NTNTG109M442b3UZh8TqLLfkC1Q@mail.gmail.com>
     [not found]           ` <20210419191539.GH9093@zn.tnic>
     [not found]             ` <CAJvTdK=VnG94ECcRVoUi8HrCbVEKc8X4_JmRTkqe+vTttf0Wsg@mail.gmail.com>
     [not found]               ` <20210419215809.GJ9093@zn.tnic>
     [not found]                 ` <CAJvTdKn6JHo02karEs0e5g+6SimS5VUcXKjCkX35WY+xkgAgxw@mail.gmail.com>
     [not found]                   ` <YIMmwhEr46VPAZa4@zn.tnic>
     [not found]                     ` <CAJvTdKnhXnynybS4eNEF_EtF26auyb-mhKLNd1D9_zvCrchZsw@mail.gmail.com>
2021-05-17  9:45                       ` Candidate Linux ABI for Intel AMX and hypothetical new related features Thomas Gleixner
2021-05-17  9:56                         ` Florian Weimer
2021-05-17 10:18                           ` Thomas Gleixner
2021-05-21 16:29                           ` Len Brown [this message]
2021-05-17 13:49                         ` Arjan van de Ven
2021-05-20 15:35                         ` Len Brown
2021-05-20 20:54                           ` Thomas Gleixner
2021-05-20 21:13                             ` Dave Hansen
2021-05-20 21:41                               ` Len Brown
2021-05-20 22:53                                 ` Dave Hansen
2021-05-21  9:41                                   ` Thomas Gleixner
2021-05-21 14:44                                   ` Florian Weimer
2021-05-21 14:49                                     ` Peter Zijlstra
2021-06-23 15:06                                       ` Florian Weimer
2021-06-23 23:11                                         ` Len Brown
2021-06-28 10:14                                           ` Enrico Weigelt, metux IT consult
2021-06-28 12:49                                             ` Florian Weimer
2021-06-30 12:22                                               ` Enrico Weigelt, metux IT consult
2021-06-30 12:41                                                 ` Willy Tarreau
2021-06-30 13:55                                                 ` Arjan van de Ven
2021-06-30 15:20                                                   ` Len Brown
2021-06-30 15:25                                                   ` Enrico Weigelt, metux IT consult
2021-05-21 16:14                                     ` Dave Hansen
2021-05-21 16:19                                       ` Florian Weimer
2021-05-21 16:26                                         ` Len Brown
2021-05-21 16:28                                         ` Dave Hansen
2021-05-21 16:31                                         ` Andy Lutomirski
2021-05-21 19:10                                           ` Thomas Gleixner
2021-05-21 20:07                                             ` Andy Lutomirski
2021-05-21 21:43                                               ` Thomas Gleixner
2021-05-21 22:07                                             ` Len Brown
2021-05-21 22:46                                               ` Thomas Gleixner
2021-05-21 23:31                                                 ` Len Brown
2021-05-22  7:16                                                   ` Florian Weimer
2021-05-22 23:55                                                     ` Andy Lutomirski
2021-05-21 23:06                                               ` Dave Hansen
2021-05-21 23:08                                                 ` Len Brown
2021-05-21 19:05                                         ` Thomas Gleixner
2021-05-20 21:22                             ` Len Brown
2021-05-20 21:41                               ` Thomas Gleixner
2021-05-20 21:49                                 ` Len Brown
2021-05-21  9:26                                   ` Thomas Gleixner
     [not found] <CALCETrW2QHa2TLvnUuVxAAheqcbSZ-5_WRXtDSAGcbG8N+gtdQ@mail.gmail.com>
2021-03-26 23:18 ` Andy Lutomirski
2021-03-27  3:39   ` Len Brown
2021-03-27  9:14     ` Borislav Petkov
2021-03-27  9:58     ` Greg KH
2021-03-29 15:47       ` Len Brown
2021-03-29 16:38         ` Len Brown
2021-03-29 16:48           ` Florian Weimer
2021-03-29 18:14           ` Andy Lutomirski
2021-03-29 18:16         ` Andy Lutomirski
2021-03-29 22:38           ` Len Brown
2021-03-30  5:08             ` Andy Lutomirski
2021-03-30  5:50               ` Noah Goldstein
2021-03-30 17:01               ` Len Brown
2021-03-30 17:05                 ` Andy Lutomirski
2021-03-30 17:56                   ` Len Brown
2021-03-30 19:12                     ` Dave Hansen
2021-03-30 20:20                       ` Andy Lutomirski
2021-03-30 20:42                         ` Len Brown
2021-03-30 22:01                           ` David Laight
2021-03-31 16:31                             ` Len Brown
2021-03-31 16:53                               ` Andy Lutomirski
2021-03-31 21:42                                 ` Robert O'Callahan
2021-03-31 22:11                                   ` Len Brown
2021-03-31 22:28                                 ` Len Brown
2021-03-31 22:45                                   ` Andy Lutomirski
2021-04-09 20:52                                     ` Len Brown
2021-04-09 21:44                                       ` Andy Lutomirski
2021-04-11 19:07                                         ` Len Brown
2021-04-12  7:59                                           ` David Laight
2021-04-12 12:19                                           ` Borislav Petkov
2021-04-12 17:14                                           ` Sean Christopherson
2021-03-31 22:52                                   ` Borislav Petkov
2021-04-09 20:55                                     ` Len Brown
2021-03-28  0:53   ` Thomas Gleixner
2021-03-29  7:27     ` Peter Zijlstra
2021-03-29 15:06     ` Dave Hansen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAJvTdK=suyVdH5U4WAdAmsJcnZbRx4tOot-Eu_SV4LSwLwP+zw@mail.gmail.com' \
    --to=lenb@kernel.org \
    --cc=arjan@linux.intel.com \
    --cc=bp@alien8.de \
    --cc=chang.seok.bae@intel.com \
    --cc=dalias@libc.org \
    --cc=dave.hansen@intel.com \
    --cc=fweimer@redhat.com \
    --cc=keno@juliacomputing.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=me@kylehuey.com \
    --cc=tglx@linutronix.de \
    --cc=w@1wt.eu \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).