From: Andy Lutomirski <luto@kernel.org>
To: Len Brown <lenb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>, Willy Tarreau <w@1wt.eu>,
Florian Weimer <fweimer@redhat.com>,
"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-abi@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>
Subject: Re: Candidate Linux ABI for Intel AMX and hypothetical new related features
Date: Fri, 16 Apr 2021 15:14:24 -0700 [thread overview]
Message-ID: <CALCETrV=Q7+D4EZiQDOwqF6O=BfMOxCpLed7=YVUJADayKAJ7Q@mail.gmail.com> (raw)
In-Reply-To: <CAJvTdKkSt-O6TkxJmE+Q2VCDqc9AzpovbpafsME2NBUqRpHEJw@mail.gmail.com>
On Fri, Apr 16, 2021 at 3:11 PM Len Brown <lenb@kernel.org> wrote:
>
> > I get it. That does not explain why LDMXCSR and VLDMXCSR cause
> > pipelines stalls.
>
> Sorry, I thought this thread was about AMX.
> I don't know the answer to your LDMXCSR and VLDMXCSR question.
My point is that every single major math extension since the original
XMM extensions (SSE, etc) has come with performance gotchas. Given
Intel's general unwillingness to document the gotchas in hardware that
is actually shipping, I'm sceptical that AMX is as delightfully
gotcha-free as you are making it out to be.
Is there any authoritative guidance at all on what actually happens,
performance-wise, when someone does AMX math?
next prev parent reply other threads:[~2021-04-16 22:14 UTC|newest]
Thread overview: 128+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 23:12 Andy Lutomirski
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
2021-03-31 8:24 ` Borislav Petkov
2021-04-12 14:19 ` Florian Weimer
2021-04-12 14:31 ` Borislav Petkov
2021-04-12 14:38 ` Florian Weimer
2021-04-12 15:08 ` Borislav Petkov
2021-04-12 15:10 ` Andy Lutomirski
2021-04-12 15:21 ` Andy Lutomirski
2021-04-12 23:46 ` Len Brown
2021-04-13 0:17 ` Thomas Gleixner
2021-04-13 1:25 ` Len Brown
2021-04-13 3:43 ` Willy Tarreau
2021-04-13 19:51 ` Len Brown
2021-04-14 9:58 ` Borislav Petkov
2021-04-14 10:06 ` Willy Tarreau
2021-04-14 10:08 ` Borislav Petkov
2021-04-14 21:57 ` Len Brown
2021-04-15 4:43 ` Borislav Petkov
2021-04-15 5:29 ` Willy Tarreau
2021-04-15 5:47 ` Borislav Petkov
2021-04-16 22:05 ` Len Brown
2021-04-19 14:14 ` Borislav Petkov
2021-04-19 18:18 ` Len Brown
2021-04-19 19:15 ` Borislav Petkov
2021-04-19 21:33 ` Len Brown
2021-04-19 21:58 ` Borislav Petkov
2021-04-23 19:35 ` Len Brown
2021-04-23 19:57 ` Borislav Petkov
2021-05-02 15:27 ` Len Brown
2021-05-03 5:18 ` Florian Weimer
2021-05-03 13:43 ` Dave Hansen
2021-05-03 13:47 ` Florian Weimer
2021-05-03 14:14 ` Dave Hansen
2021-05-07 18:44 ` Thomas Gleixner
2021-05-07 18:50 ` Andy Lutomirski
2021-05-07 19:22 ` Thomas Gleixner
2021-05-08 9:45 ` Thomas Gleixner
2021-05-18 20:39 ` Len Brown
2021-05-19 23:29 ` Andy Lutomirski
2021-05-20 19:16 ` Len Brown
2021-05-17 9:45 ` Thomas Gleixner
2021-05-17 9:56 ` Florian Weimer
2021-05-17 10:18 ` Thomas Gleixner
2021-05-21 16:29 ` Len Brown
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
[not found] ` <93e3b500-5992-a674-18e6-445d1db7b1f0@metux.net>
2021-06-28 12:49 ` Florian Weimer
[not found] ` <84be3cfd-e825-ae75-bbae-2bbd3360daa7@metux.net>
2021-06-30 12:41 ` Willy Tarreau
2021-06-30 13:55 ` Arjan van de Ven
2021-06-30 15:20 ` Len Brown
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
2021-04-19 23:52 ` Paul Eggert
2021-04-13 20:16 ` Andy Lutomirski
2021-04-13 22:47 ` Len Brown
2021-04-13 22:58 ` Andy Lutomirski
2021-04-14 21:48 ` Len Brown
2021-04-15 16:24 ` Andy Lutomirski
2021-04-15 17:00 ` Dave Hansen
2021-04-15 17:38 ` Andy Lutomirski
2021-04-16 21:54 ` Len Brown
2021-04-16 22:03 ` Andy Lutomirski
2021-04-16 22:10 ` Len Brown
2021-04-16 22:14 ` Andy Lutomirski [this message]
2021-04-17 1:57 ` Len Brown
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