Received: by 2002:a25:c593:0:0:0:0:0 with SMTP id v141csp625248ybe; Fri, 13 Sep 2019 03:37:51 -0700 (PDT) X-Google-Smtp-Source: APXvYqyrx9oDJPT4O4+5B1wEHvt0RYWH0oroWY9nQ7L8SUlGeKr/ZayTusPLZ4M0WMuP8zJqvPYG X-Received: by 2002:a17:906:814f:: with SMTP id z15mr38672391ejw.13.1568371071781; Fri, 13 Sep 2019 03:37:51 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568371071; cv=none; d=google.com; s=arc-20160816; b=pUaAJkw7VzKbdOM9RTEhhW+MtnnLE2a2OHTZqTyPzVfV32G2EGsz3JLx17hYMOGoOp Ci+R6J2os7OUAFyREpzhLE1jlNDM+FAAavc6QAwwdYCh592N+JxxuwrmcmZvaW6Z4Flv gwnUvH+usWX8TocobkeEZSDuaforwZ/P5pqNL9xZp903nkllN9s1z6lizlaN0VVWLg5/ 5a1l0ihi0JBA+MHn/vscxBean4XfJ5tYLDL7+ChEd4FIFnoCE+ztsj8Yzuqj+O2WaWpK rDptFc3Hf7/0GbKFD4bHxxjTnoHj+jK9Wp3xyLuLzDDL+krbUlsG3TUK5NhBtugq5cJV qqQw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=XRSaXvuR2HkdDHn2KxSCFVlcMnDeMXafFKpWXJtDEn4=; b=sw5gzox4CYVAKKQHXd9VngoEMe5OuQ+mTWgse9iejk0agM7wDV/Anp9rzKL0fDXqn/ j7aC790ViotQZ7HwKDjVdUXGs07sA+zoKGv1NbMhlt1wFxO88kG2brdID4hqWMWKmH8J QZp6X1KZepJ8bA7NMxguGdt/yO9njIJ4IRO4/JIRleWWsqyHLPVTQl0vlJXdQMImutqu 7pTDv9hekuv1XE7Sz2kbcRI0dlbaIiicPesWCdVjje20GFIwdv8NatPuTEhblD2RySxl hv+VvWu5BdckZTXgXuw1jgJ0LWfmTGDL028oGwTRCWs15lS1fRF34chCFnK/mjx8CFtk EXHw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=BE8rIGH5; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u2si6763005edp.191.2019.09.13.03.37.16; Fri, 13 Sep 2019 03:37:51 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=BE8rIGH5; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728654AbfIMHuL (ORCPT + 99 others); Fri, 13 Sep 2019 03:50:11 -0400 Received: from mail.skyhub.de ([5.9.137.197]:38126 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727405AbfIMHuL (ORCPT ); Fri, 13 Sep 2019 03:50:11 -0400 Received: from zn.tnic (p200300EC2F0DC500B05269A39FD21165.dip0.t-ipconnect.de [IPv6:2003:ec:2f0d:c500:b052:69a3:9fd2:1165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id E7FE51EC067D; Fri, 13 Sep 2019 09:50:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1568361010; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=XRSaXvuR2HkdDHn2KxSCFVlcMnDeMXafFKpWXJtDEn4=; b=BE8rIGH5BHcHeOp1q6ugzEM9TyofTe8wbVfm0pDiLakB+LJKkWfwwv/x27AiZwjy03VlJ9 5R9tGMENB/EjLzE4jIo/UqfxqoZPVK6PxQRfM5ROo/GzLIOSMst438dynlKbqUTQO/nlj0 TXIo06vJEc8+BvYk7Ac1OE7dEf47mug= Date: Fri, 13 Sep 2019 09:50:08 +0200 From: Borislav Petkov To: Ingo Molnar Cc: x86-ml , Andy Lutomirski , Josh Poimboeuf , Linus Torvalds , lkml Subject: Re: [RFC] Improve memset Message-ID: <20190913075008.GA20638@zn.tnic> References: <20190913072237.GA12381@zn.tnic> <20190913073530.GA125477@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190913073530.GA125477@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 13, 2019 at 09:35:30AM +0200, Ingo Molnar wrote: > That looks exciting - I'm wondering what effects this has on code > footprint - for example defconfig vmlinux code size, and what the average > per call site footprint impact is? > > If the footprint effect is acceptable, then I'd expect this to improve > performance, especially in hot loops. Well, it grows a bit but that's my conglomerate ugly patch so I'll redo that test when I've cleaned it up: text data bss dec hex filename 19699924 5201260 1642568 26543752 1950688 vmlinux.before 19791674 5201388 1552456 26545518 1950d6e vmlinux.after -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette