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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 11EC3C433F5 for ; Thu, 6 Sep 2018 15:52:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B97492075B for ; Thu, 6 Sep 2018 15:52:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="GcZ2XvOk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B97492075B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=zx2c4.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730434AbeIFU2f (ORCPT ); Thu, 6 Sep 2018 16:28:35 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:39257 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730304AbeIFU2f (ORCPT ); Thu, 6 Sep 2018 16:28:35 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 39c78035; Thu, 6 Sep 2018 15:36:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=mime-version :references:in-reply-to:from:date:message-id:subject:to:cc :content-type; s=mail; bh=Dxm3pVP+yCo9w/F7ZNLQgtpezbI=; b=GcZ2Xv OkPKlJ8PyaW/Qk3SZTCrNDkeaM9vh1FaJCIwz8HhQjdTBrQmfNUg+dxX+ER1Ohgu ZSvxVMFwSDg/c9KNgKmOZzMlYlTfFsh37yqMmtULS+WKI9+BYKcCVB+kM2h8sAfd zMSe3Mj8PmTlxlwvG9E5lNsftfK/C6dkLJFcYksjnwMtZ4iyBP79zksvaQTemjoJ d3F2RxahKhMC38MWwP70uozVdmC2eGdxLkxK2Uh1t4onOD30+2NuK+pY/Rli5Wib w+SA+mqQ9oUrxEYGv8bXFYB2oqLtjVHOCcwU3h+BpV/Vp2deuVKWYhfZm1gdCFRO d+pwrH9aidU4Os4Q== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id e5f98880 (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128:NO); Thu, 6 Sep 2018 15:36:21 +0000 (UTC) Received: by mail-oi0-f44.google.com with SMTP id l202-v6so21436799oig.7; Thu, 06 Sep 2018 08:52:25 -0700 (PDT) X-Gm-Message-State: APzg51Bjd5dUHkYZUpIW6yHZ3imXZYxv4bkkcDQ4RDwCMmUlQ5M2CNc6 jiKfhxHrEj1o1zBa1RHbfsqJ7ONbWAqotf30Ksw= X-Google-Smtp-Source: ANB0VdazEdYtqK/gdhZwQJeIjHCRibmVujiNX80Rxe/+R5gCLrTOS0SzBaMMbkQ5r69hHSfiB4Xldymnn09dArQR8iw= X-Received: by 2002:aca:b641:: with SMTP id g62-v6mr3308879oif.71.1536249144535; Thu, 06 Sep 2018 08:52:24 -0700 (PDT) MIME-Version: 1.0 References: <20180824213849.23647-1-Jason@zx2c4.com> <20180824213849.23647-2-Jason@zx2c4.com> In-Reply-To: From: "Jason A. Donenfeld" Date: Thu, 6 Sep 2018 09:52:13 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 01/17] asm: simd context helper API To: Thomas Gleixner Cc: Andrew Lutomirski , LKML , Netdev , David Miller , Greg Kroah-Hartman , Samuel Neves , linux-arch@vger.kernel.org, Rik van Riel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Thu, Sep 6, 2018 at 9:29 AM Thomas Gleixner wrote: > > On Sat, 1 Sep 2018, Jason A. Donenfeld wrote: > > On Sat, Sep 1, 2018 at 2:32 PM Andy Lutomirski wrote: > > > I tend to think the right approach is to merge Jason's code and then > > > make it better later. Even with a totally perfect lazy FPU restore > > > implementation on x86, we'll probably still need some way of dealing > > > with SIMD contexts. I think we're highly unlikely to ever a allow > > > SIMD usage in all NMI contexts, for example, and there will always be > > > cases where we specifically don't want to use all available SIMD > > > capabilities even if we can. For example, generating random numbers > > > does crypto, but we probably don't want to do *SIMD* crypto, since > > > that will force a save and restore and will probably fire up the > > > AVX512 unit, and that's not worth it unless we're already using it for > > > some other reason. > > > > > > Also, as Rik has discovered, lazy FPU restore is conceptually > > > straightforward but isn't entirely trivial :) > > > > Sounds good. I'll move ahead on this basis. > > Fine with me. Do you want to pull this single patch [01/17] into your tree now, and then when I submit v3 of WireGuard and such, I can just drop this patch from it, and then the rest will enter like usual networking stuff through Dave's tree? Jason