Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753692AbcKUJt3 (ORCPT ); Mon, 21 Nov 2016 04:49:29 -0500 Received: from mail-wj0-f195.google.com ([209.85.210.195]:35661 "EHLO mail-wj0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752870AbcKUJt2 (ORCPT ); Mon, 21 Nov 2016 04:49:28 -0500 Date: Mon, 21 Nov 2016 10:49:23 +0100 From: Ingo Molnar To: Frederic Weisbecker Cc: Martin Schwidefsky , LKML , Tony Luck , Wanpeng Li , Peter Zijlstra , Michael Ellerman , Heiko Carstens , Benjamin Herrenschmidt , Thomas Gleixner , Paul Mackerras , Fenghua Yu , Rik van Riel , Stanislaw Gruszka Subject: Re: [PATCH 00/36] cputime: Convert core use of cputime_t to nsecs Message-ID: <20161121094923.GA22910@gmail.com> References: <1479406123-24785-1-git-send-email-fweisbec@gmail.com> <20161118130846.7da515cc@mschwide> <20161118144700.GA31560@lerouge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161118144700.GA31560@lerouge> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 913 Lines: 23 * Frederic Weisbecker wrote: > > But I am still not happy about the approach. What is the compelling reason for > > this change except for the "but it looks ugly"? > > The diffstat (600 lines removed). Also the fact that we have all these > workarounds in the core code just for the special case of 1 arch (s390) and a > half (powerpc with CONFIG_VIRT_CPU_ACCOUNTING_NATIVE). > > I'd much rather have all that complexity moved in a vtime_native.c shared by > s390 and powerpc that takes care of proper accumulation in cputime_t and flushes > that on ticks in nsecs rather than having all these cputime_t game all over the > kernel. I agree - we really want to concentrate complexity in such a fashion and generally standardize on nanosecs, and the diffstat of the patchset is really nice. The patchset obviously has to build (and work!) on s390/powerpc properly. Thanks, Ingo