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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 3DD2CC10F0E for ; Mon, 15 Apr 2019 09:47:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08FA020833 for ; Mon, 15 Apr 2019 09:47:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=codeweavers.com header.i=@codeweavers.com header.b="q6XInizr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727018AbfDOJro (ORCPT ); Mon, 15 Apr 2019 05:47:44 -0400 Received: from 50-203-203-244-static.hfc.comcastbusiness.net ([50.203.203.244]:59106 "EHLO mail.codeweavers.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725798AbfDOJro (ORCPT ); Mon, 15 Apr 2019 05:47:44 -0400 X-Greylist: delayed 1013 seconds by postgrey-1.27 at vger.kernel.org; Mon, 15 Apr 2019 05:47:43 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=codeweavers.com; s=6377696661; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=hNO72mY6owZc9BbDkbkB6z1MumKqdRQ98mR/U6MEzko=; b=q6XInizrZMsjXaI5QsIP0B2zq bNLE+82bw2qRak7Auo29DUAx+nKMkn9AdFa0uJz77YL2JUCo1MDH/GvA6RIb0VAc69uyEnV/OrdOl AIFqaL1Z2X87ZTiV8bRcmH/aTS4pocqTAltHifuoGYBiOU4ZettOdUT88/rJPZOmQCQ2M=; Received: from merlot.physics.ox.ac.uk ([163.1.241.98] helo=merlot) by mail.codeweavers.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hFxx3-0008JV-VR; Mon, 15 Apr 2019 04:30:59 -0500 Received: from daviesh by merlot with local (Exim 4.90_1) (envelope-from ) id 1hFxwp-0005h8-KS; Mon, 15 Apr 2019 10:30:43 +0100 Date: Mon, 15 Apr 2019 10:30:43 +0100 From: Huw Davies To: Thomas Gleixner Cc: linux kernel , Andy Lutomirski , Vincenzo Frascino Subject: Re: [PATCH 2/3] x86/vdso: Allow clock specific mult and shift values Message-ID: <20190415093042.GA21726@merlot.physics.ox.ac.uk> References: <20190411101205.10006-1-huw@codeweavers.com> <20190411101205.10006-3-huw@codeweavers.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 14, 2019 at 12:53:32PM +0200, Thomas Gleixner wrote: > So it stays in the same cache line, but as we move the VDSO to generic > code, the mask field needs to stay and this will make basetime[CLOCK_MONOTONIC] > overlap into the next cache line. Thanks for the great review; this is a good point. > See https://lkml.kernel.org/r/alpine.DEB.2.21.1902231727060.1666@nanos.tec.linutronix.de > for an alternate solution to this problem, which avoids this and just gives > CLOCK_MONOTONIC_RAW a separate storage space alltogether. I can certainly do this for the x86 vdso. Would that be useful or should I wait for Vincenzo's work on the generic vdso first? Many thanks, Huw.