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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 748D8C49ED7 for ; Fri, 13 Sep 2019 07:50:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A2F220830 for ; Fri, 13 Sep 2019 07:50:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="BE8rIGH5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728969AbfIMHuL (ORCPT ); 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