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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable 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 9B723C282DD for ; Mon, 10 Jun 2019 11:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74BDE2063F for ; Mon, 10 Jun 2019 11:37:22 +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="fXJ3tPQb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389446AbfFJLhR (ORCPT ); Mon, 10 Jun 2019 07:37:17 -0400 Received: from mail.codeweavers.com ([50.203.203.244]:33844 "EHLO mail.codeweavers.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389346AbfFJLhR (ORCPT ); Mon, 10 Jun 2019 07:37:17 -0400 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=/SHmrx2OGszMojwi0lkosVsMjx6Rojf4MNms94FoV6s=; b=fXJ3tPQbcxZUY4oPTr+zNREb2 +TZVfbKrwmmpFX0cNPelz/zBugEAZq3q+j53J1q82ddkA15wUt52LnzMYzBHR580J5t182ToSyJ3h BOU7JidlIXFf0Nm8TND3eg0KC+FRUjmi23Cg8Bk7TbKCiBGyqEm706PZ+pFNELL2d0L4c=; 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 1haIcW-0005Ee-5w; Mon, 10 Jun 2019 06:37:49 -0500 Received: from daviesh by merlot with local (Exim 4.90_1) (envelope-from ) id 1haIbs-0003Fy-Tx; Mon, 10 Jun 2019 12:37:09 +0100 Date: Mon, 10 Jun 2019 12:37:08 +0100 From: Huw Davies To: Vincenzo Frascino Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org, Catalin Marinas , Will Deacon , Arnd Bergmann , Russell King , Ralf Baechle , Paul Burton , Daniel Lezcano , Thomas Gleixner , Mark Salyzyn , Peter Collingbourne , Shuah Khan , Dmitry Safonov <0x7f454c46@gmail.com>, Rasmus Villemoes Subject: Re: [PATCH v6 01/19] kernel: Standardize vdso_datapage Message-ID: <20190610113708.GE11076@merlot.physics.ox.ac.uk> References: <20190530141531.43462-1-vincenzo.frascino@arm.com> <20190530141531.43462-2-vincenzo.frascino@arm.com> <20190610092751.GA11076@merlot.physics.ox.ac.uk> <58cedde2-0d54-7d2d-f519-77cb71f543fd@arm.com> <20190610103151.GD11076@merlot.physics.ox.ac.uk> <83ab2758-0e8c-35d5-906a-0338bcee3310@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <83ab2758-0e8c-35d5-906a-0338bcee3310@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Message-ID: <20190610113708.GFutn48l1-3ismWnb2kIyv0K2AADSAN7XmgcnbLDmSQ@z> On Mon, Jun 10, 2019 at 12:07:45PM +0100, Vincenzo Frascino wrote: > On 10/06/2019 11:31, Huw Davies wrote: > > On Mon, Jun 10, 2019 at 11:17:48AM +0100, Vincenzo Frascino wrote: > >> On 10/06/2019 10:27, Huw Davies wrote: > >>> On Thu, May 30, 2019 at 03:15:13PM +0100, Vincenzo Frascino wrote: > >>>> --- /dev/null > >>>> +++ b/include/vdso/datapage.h > >>>> @@ -0,0 +1,91 @@ > >>>> +/* SPDX-License-Identifier: GPL-2.0 */ > >>>> +#ifndef __VDSO_DATAPAGE_H > >>>> +#define __VDSO_DATAPAGE_H > >>>> + > >>>> +#ifdef __KERNEL__ > >>>> + > >>>> +#ifndef __ASSEMBLY__ > >>>> + > >>>> +#include > >>>> +#include > >>>> +#include > >>>> + > >>>> +#define VDSO_BASES (CLOCK_TAI + 1) > >>>> +#define VDSO_HRES (BIT(CLOCK_REALTIME) | \ > >>>> + BIT(CLOCK_MONOTONIC) | \ > >>>> + BIT(CLOCK_BOOTTIME) | \ > >>>> + BIT(CLOCK_TAI)) > >>>> +#define VDSO_COARSE (BIT(CLOCK_REALTIME_COARSE) | \ > >>>> + BIT(CLOCK_MONOTONIC_COARSE)) > >>>> +#define VDSO_RAW (BIT(CLOCK_MONOTONIC_RAW)) > >>>> + > >>>> +#define CS_HRES_COARSE 0 > >>>> +#define CS_RAW 1 > >>> > >>> CS_HRES_COARSE seems like a confusing name choice to me. What you > >>> really mean is not RAW. > >>> > >>> How about CS_ADJ to indicate that its updated by adjtime? > >>> CS_XTIME might be another option. > >>> > >> > >> I divided the timers in 3 sets (HRES, COARSE, RAW), CS_HRES_COARSE refers to the > >> first two and CS_RAW to the third. I will ad a comment to explain the logic in > >> the next iteration. > > > > I'm thinking ahead about a possible CLOCK_MONOTONIC_RAW_COARSE (which > > would be useful at least for Wine). In that case you'd have four clock > > types non-raw and raw, each with either hres or coarse. > > > > Thanks for this, I was not aware of CLOCK_MONOTONIC_RAW_COARSE. > I tried to find, though, some details, but I could not find any. Could you > please provide some reference? It doesn't exist yet ;-) However it doesn't seem crazy that such a clock should exist. I was really using it to illustrate that raw / non-raw is orthogonal to hres / coarse. That being said, this really doesn't matter that much. Huw.