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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,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 203CBC31E50 for ; Sun, 16 Jun 2019 17:49:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF62E208E3 for ; Sun, 16 Jun 2019 17:49:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ntz43rBU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727375AbfFPRtv (ORCPT ); Sun, 16 Jun 2019 13:49:51 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:42602 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726121AbfFPRtv (ORCPT ); Sun, 16 Jun 2019 13:49:51 -0400 Received: by mail-wr1-f65.google.com with SMTP id x17so7434299wrl.9; Sun, 16 Jun 2019 10:49:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=/hRwW8vMhzdua2ppKrVssHlA+91ZHXY3leNMzjUdRY4=; b=ntz43rBUdHCHjbQbMNk77s+2nvtyM808P08aRWuPumkZQKQBX6uX3qR7c6QxUm+kfY S4EgNUI3AZpmQZsUzFnWB4RT0LaH8Laq6DncsDkMX9fm+3bFkj+ZzdhB2lYU/aNpJi6Q tkDsXCrXGbev++hsjRGw0l5l9sCVD2tQCDq6NylLb8bCbRMF4u4xmiPyQZ8bkcKhL9yx 3Q+ki0r9WsqqZe2dk52DqmGmh72uW5896XBCbFJC3NP6YDXchAPXDYyCvEW8DRsNJQfT CRjw/s8FNnFFQYUp42lQ3yLiWRPURM1JKRP4ffG2oZPH/ccsRYAY3kGUmK+4Hnsficio YaPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=/hRwW8vMhzdua2ppKrVssHlA+91ZHXY3leNMzjUdRY4=; b=tqovYPrMy7TFiV6bhAJAXX+OxqNwuTpUFj9WLyj2v1PL25wpMbU2qKB6BtHU5ggFTk j/v+FUEBMMnWbszfagtWryaGzYTfZ+p1H3Oz1vQQaC3/8NIK1KAt3oly73AWYPAzY7o/ 0iQzQK5xJxN3YD7ywKthAd/2bhMOy8D63tl/XUqesptKpTw2Ji60tC7amP3RqCEyviOA bLmZZqTD4Y0WwiXCa3sclPZpxNRht+r8FBphBzwfkxEn6upqAkTM8AMhwmV8o9ZlKT5E ZA686ZJGV3Bt838a7xvOncnSqYhm58lWLtfOFCw1LoBoUcCGPAphqd2Asaq7CW8jWcXl YnxA== X-Gm-Message-State: APjAAAXbKPtLzWQ9gdcmHlI1RgPcpv3seheTnL9L4Z4xiz3jHjAq/IJq W0Whx6LIwlD2z7nTclhQDKXtj1X8nYw= X-Google-Smtp-Source: APXvYqw8+eaMfU3JJptUOf9opfQ4Ex/advZBsHRVGuf0+Z2384xm0miDcOtIHBye56a10TFgRW3FAw== X-Received: by 2002:adf:ec4c:: with SMTP id w12mr52857090wrn.160.1560707389051; Sun, 16 Jun 2019 10:49:49 -0700 (PDT) Received: from [10.83.36.153] ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id x8sm10023143wmc.5.2019.06.16.10.49.47 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Sun, 16 Jun 2019 10:49:48 -0700 (PDT) Subject: Re: [PATCHv4 15/28] x86/vdso: Add offsets page in vvar To: Thomas Gleixner , Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Andrei Vagin , Adrian Reber , Andy Lutomirski , Arnd Bergmann , Christian Brauner , Cyrill Gorcunov , "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Jeff Dike , Oleg Nesterov , Pavel Emelyanov , Shuah Khan , Vincenzo Frascino , containers@lists.linux-foundation.org, criu@openvz.org, linux-api@vger.kernel.org, x86@kernel.org, Andrei Vagin References: <20190612192628.23797-1-dima@arista.com> <20190612192628.23797-16-dima@arista.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: Date: Sun, 16 Jun 2019 18:49:47 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/14/19 2:58 PM, Thomas Gleixner wrote: > On Wed, 12 Jun 2019, Dmitry Safonov wrote: >> >> +#ifdef CONFIG_TIME_NS >> +notrace static __always_inline void clk_to_ns(clockid_t clk, struct timespec *ts) >> +{ >> + struct timens_offsets *timens = (struct timens_offsets *) &timens_page; >> + struct timespec64 *offset64; >> + >> + switch (clk) { >> + case CLOCK_MONOTONIC: >> + case CLOCK_MONOTONIC_COARSE: >> + case CLOCK_MONOTONIC_RAW: >> + offset64 = &timens->monotonic; >> + break; >> + case CLOCK_BOOTTIME: >> + offset64 = &timens->boottime; >> + default: >> + return; >> + } >> + >> + ts->tv_nsec += offset64->tv_nsec; >> + ts->tv_sec += offset64->tv_sec; >> + if (ts->tv_nsec >= NSEC_PER_SEC) { >> + ts->tv_nsec -= NSEC_PER_SEC; >> + ts->tv_sec++; >> + } >> + if (ts->tv_nsec < 0) { >> + ts->tv_nsec += NSEC_PER_SEC; >> + ts->tv_sec--; >> + } > > I had to think twice why adding the offset (which can be negative) can > never result in negative time being returned. A comment explaining this > would be appreciated. > > As I'm planning to merge Vincezos VDSO consolidation into 5.3, can you > please start to work on top of his series, which should be available as > final v7 next week hopefully. Yes, will rebase on the top of his series. Thanks much, Dmitry