From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 21 Feb 2016 14:19:09 +0100 (CET) Received: from mail-lf0-f41.google.com ([209.85.215.41]:34676 "EHLO mail-lf0-f41.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27007423AbcBUNTHy9qFF (ORCPT ); Sun, 21 Feb 2016 14:19:07 +0100 Received: by mail-lf0-f41.google.com with SMTP id j78so78985070lfb.1 for ; Sun, 21 Feb 2016 05:19:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cogentembedded-com.20150623.gappssmtp.com; s=20150623; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-type:content-transfer-encoding; bh=w2Gpw6iSZx6psqKDVROajll1Boms1K3B+DK6FFVhGfE=; b=zlurkZAVjjcDenwsLTBs/jNe5HeFjeRy64QJlry0vudRDd7go0LBod1nKEPU/eGjHH obwnlgK1C4uZoPiMnIAO2KqdaTGIhLtr+U0AzG2o6qPLcs3wMw4lenuUDVPh58CE4xfQ NgvLH30CjJ7zc0tMaRuRLiWuIW8xn3n3VaVjwHESUTUfHLDiEzp1BVBA35TpnxNnsR1o Y5uN1zkPZtKijQUMuPPdK4JrSTw7fyw5VqTW/liV9HQJaR8M0BmICDw4VDvoRqohuLkg QaLPLbhPewlNYIOYstGLb2DIKFTA2rihijif8aZtlyWwLk0XavJAYNekLI6iGFzUMtWo O/FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-type :content-transfer-encoding; bh=w2Gpw6iSZx6psqKDVROajll1Boms1K3B+DK6FFVhGfE=; b=TRk9K/XTfqBUXmgGnt+xL8zoo1lBaSK/asK/Iz6AvMm9p0fsT3KVOfvFo1iuT3bVgc MqYHtbpKPh9Uzsjd8gNc/khltrrteYI73tq9ud/4oxdNCYo5YOtzt9fuE+x0MS6RI/gI MDaOoJB7gYqCt31tFBM5H8qx+OYgsyiBo7xDdyK3Ep93hqeV8N7M2frDinqslXXQpBX8 3i+OEbZ8oH7Mg3TIfGsC4h9AWggqF8RXBvYCNIEcZrPaMpgzjx/T49y6PsWpxyGCMYFJ UQ5/x6IpAe27crxA8jSnqcXT/CWioYIqgcYH27yQ1oid0fZZG8aK8ECkKRgLAJ0CP4uQ zapQ== X-Gm-Message-State: AG10YOQ7xjjaZNpE96qnb9SMBfdOqvI/j/cGcak/KLVQuLMVL0yhAeQE8ERaEFbW5hov+Q== X-Received: by 10.25.86.195 with SMTP id k186mr2009659lfb.155.1456060742248; Sun, 21 Feb 2016 05:19:02 -0800 (PST) Received: from [192.168.4.126] ([83.149.8.15]) by smtp.gmail.com with ESMTPSA id k3sm2766553lbp.9.2016.02.21.05.18.59 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 21 Feb 2016 05:19:01 -0800 (PST) Subject: Re: [PATCH] MIPS: vdso: flush the vdso data page to update it on all processes To: Hauke Mehrtens , linux-mips@linux-mips.org, ralf@linux-mips.org References: <1456059443-13889-1-git-send-email-hauke@hauke-m.de> Cc: alex.smith@imgtec.com, "# v4 . 4+" From: Sergei Shtylyov Message-ID: <56C9B943.1080006@cogentembedded.com> Date: Sun, 21 Feb 2016 16:18:59 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1456059443-13889-1-git-send-email-hauke@hauke-m.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 52148 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: sergei.shtylyov@cogentembedded.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Hello. On 2/21/2016 3:57 PM, Hauke Mehrtens wrote: > Without flushing the vdso data page the vdso call is working on dated > or unsynced data. This resulted in problems where the clock_gettime > vdso call returned a time 6 seconds later after a 3 sounds sleep, > while the syscall reported a time 3 sounds later like expected. This s/sounds/seconds/ perhaps? > happened very often and I got these ping results for example: > > root@OpenWrt:/# ping 192.168.1.255 > PING 192.168.1.255 (192.168.1.255): 56 data bytes > 64 bytes from 192.168.1.3: seq=0 ttl=64 time=0.688 ms > 64 bytes from 192.168.1.3: seq=1 ttl=64 time=4294172.045 ms > 64 bytes from 192.168.1.3: seq=2 ttl=64 time=4293968.105 ms > 64 bytes from 192.168.1.3: seq=3 ttl=64 time=4294055.920 ms > 64 bytes from 192.168.1.3: seq=4 ttl=64 time=4294671.913 ms > > The flush is now done like it is done on the arm architecture code. > > This was tested on a Lantiq/Intel VRX288 (MIPS BE 34Kc V5.6 CPU with > two VPEs) > > Signed-off-by: Hauke Mehrtens > Cc: # v4.4+ [...] MBR, Sergei