From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EAA7C433B4 for ; Tue, 13 Apr 2021 19:52:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DBA4F613B1 for ; Tue, 13 Apr 2021 19:52:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346279AbhDMTwZ (ORCPT ); Tue, 13 Apr 2021 15:52:25 -0400 Received: from mail-ed1-f49.google.com ([209.85.208.49]:42623 "EHLO mail-ed1-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231802AbhDMTwX (ORCPT ); Tue, 13 Apr 2021 15:52:23 -0400 Received: by mail-ed1-f49.google.com with SMTP id d21so709993edv.9; Tue, 13 Apr 2021 12:52:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MKPJ/sPO22gfiF94hxW9McaKDO7hAr85uineOjYitIE=; b=EsqP/vO9ZbAGLtAvwCIwrZp+lcSc9fGHvQ6IPAvh6ShjOh7DNeSXG2gu2VKx7WpdJN QgXikBxoaIZZqpOH+dPkgA4cnSbDdxjm3YMM4yOG7X1SPmLHWK0rw9XP4CIbqu3CLujl hjaGZqHq+8h5k7B4BxF09zySU7f2xjQYL2b5XxipGmhVDAhC9AKT1XRfIVveHQYbCx1N k8fZWTrzInTGFgsr/bP5oa6NeXFQLmMkYWv9jbm3fz/7kq+K+QxkhZ1A8Fdzi5qCkaVs hPMHw7Rd3O7z/ck5Y7SQRg8mrLJKi3e4X9Q3hDfjEqXLrJHEHT9JFDXEExTQTJUaT286 wvig== X-Gm-Message-State: AOAM533oFfH6WbPYxnCbYugN424/1zZEr6tPKXFYWKt5fmdYWTYYEcYA cmdWGLmK88iT20EP1JVSnD0whpY2DmEE3sPV2eU= X-Google-Smtp-Source: ABdhPJzEqOYPwZS3m7LJ3+5X1Ra00fK1HTMUfkVcy19u7Iebm2WDwBUgomgbirKpn5+pkzU5Lh/OVVibfti7SdBzq0g= X-Received: by 2002:a05:6402:35c9:: with SMTP id z9mr36783451edc.94.1618343522468; Tue, 13 Apr 2021 12:52:02 -0700 (PDT) MIME-Version: 1.0 References: <87lf9nk2ku.fsf@oldenburg.str.redhat.com> <20210413034346.GA22861@1wt.eu> In-Reply-To: <20210413034346.GA22861@1wt.eu> From: Len Brown Date: Tue, 13 Apr 2021 15:51:50 -0400 Message-ID: Subject: Re: Candidate Linux ABI for Intel AMX and hypothetical new related features To: Willy Tarreau Cc: Andy Lutomirski , Florian Weimer , "Bae, Chang Seok" , Dave Hansen , X86 ML , LKML , linux-abi@vger.kernel.org, "libc-alpha@sourceware.org" , Rich Felker , Kyle Huey , Keno Fischer Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for sharing your perspective, Willy. I agree that if your application is so sensitive that you need to hand-code your own memcmp, then linking with (any) new version of (any) dynamic library is a risk you must consider carefully. AMX does the type of matrix multiplication that AI algorithms use. In the unlikely event that you or one of the libraries you call are doing the same, then you will be very happy with AMX. Otherwise, you'll probably not use it. I acknowledge the issue with the toolchain transparently using AVX-512 for copying data, and how that approach impacted systems with a poor AVX-512 hardware implementation. FWIW. I'm not aware of any plans to implicitly use AMX this way, and I'm not aware of any non-Xeon AMX implementations in the near future. cheers, Len Brown, Intel Open Source Technology Center