Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754809AbdGTAcO (ORCPT ); Wed, 19 Jul 2017 20:32:14 -0400 Received: from mail-io0-f170.google.com ([209.85.223.170]:33881 "EHLO mail-io0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754117AbdGTAcM (ORCPT ); Wed, 19 Jul 2017 20:32:12 -0400 MIME-Version: 1.0 In-Reply-To: References: <1499417992-3238-1-git-send-email-elena.reshetova@intel.com> <1499417992-3238-2-git-send-email-elena.reshetova@intel.com> <87bmottgo4.fsf@xmission.com> <20170719153546.37567fbf77861653172fa263@linux-foundation.org> <20170719225427.GD14395@linux-80c1.suse> <20170719155833.641a283467bf6b89a7d2e56b@linux-foundation.org> <20170719231134.GF14395@linux-80c1.suse> From: Kees Cook Date: Wed, 19 Jul 2017 17:32:10 -0700 X-Google-Sender-Auth: 9FYRXWijB1FKHQutVJjTEUA-6Ws Message-ID: Subject: Re: [PATCH 1/3] ipc: convert ipc_namespace.count from atomic_t to refcount_t To: Davidlohr Bueso Cc: Andrew Morton , "Eric W. Biederman" , Elena Reshetova , LKML , Peter Zijlstra , Greg KH , Ingo Molnar , Alexey Dobriyan , "Serge E. Hallyn" , arozansk@redhat.com, Hans Liljestrand , David Windsor Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1103 Lines: 33 On Wed, Jul 19, 2017 at 4:20 PM, Kees Cook wrote: > On Wed, Jul 19, 2017 at 4:11 PM, Davidlohr Bueso wrote: >> May I suggest using mmtests with the following config file: >> >> https://github.com/gormanm/mmtests/blob/7e070a810bc0af92e592e5121d0ea75fada51aeb/configs/config-global-dhp__workload-ipc-scale-short >> >> It will run two of Manfred's ipcscale sem benchmarks. > > I'll see if I can figure out how to use this for testing the fast > refcount protection: > https://lkml.org/lkml/2017/7/18/1223 > > Then we could see: > > before conversion > after conversion > with CONFIG_REFCOUNT_FULL > with fast refcount protection I have no idea how to read this report. It seems to be mostly noise (multiple baseline runs seem to show greater variability than compared against the other possible results). Test runs were atomic_t, atomic_t-2, refcount_t, refcount-full, and refcount-fast. (Two baselines, refcount_t conversion, with FULL, and with the fast implementation.) Output here: http://pastebin.ubuntu.com/25129382/ -Kees -- Kees Cook Pixel Security