From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752015AbbERBhU (ORCPT ); Sun, 17 May 2015 21:37:20 -0400 Received: from ozlabs.org ([103.22.144.67]:46447 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751878AbbERBhP (ORCPT ); Sun, 17 May 2015 21:37:15 -0400 Message-ID: <1431913033.13218.2.camel@ellerman.id.au> Subject: Re: [PATCH v2] Documentation/arch: Add kernel feature descriptions and arch support status under Documentation/features/ From: Michael Ellerman To: Ingo Molnar Cc: Andrew Morton , Josh Triplett , Borislav Petkov , Jonathan Corbet , Peter Zijlstra , Andy Lutomirski , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , Linus Torvalds , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org Date: Mon, 18 May 2015 11:37:13 +1000 In-Reply-To: <20150515074949.GB14993@gmail.com> References: <20150513094622.GC11030@gmail.com> <20150513094756.GD11030@gmail.com> <20150513131835.GJ1517@pd.tnic> <20150513134842.GA1657@gmail.com> <20150513162757.GA21894@x> <20150513150523.ddd65d7cd51f820b78f0c8e3@linux-foundation.org> <20150514101518.GA27550@gmail.com> <20150514103544.GA7027@gmail.com> <20150514123835.1bf436bc35d711f8dbf9bc0f@linux-foundation.org> <1431644248.2981.1.camel@ellerman.id.au> <20150515074949.GB14993@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.10-0ubuntu1~14.10.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2015-05-15 at 09:49 +0200, Ingo Molnar wrote: > * Michael Ellerman wrote: > > > On Thu, 2015-05-14 at 12:38 -0700, Andrew Morton wrote: > > > > Add arch support matrices for more than 40 generic kernel features > > > > that need per architecture support. > > > > > > > > Each feature has its own directory under Documentation/features/feature_name/, > > > > and the arch-support.txt file shows its current arch porting status. > > > > > > It would be nice to provide people with commit IDs to look at, but the > > > IDs won't be known at the time the documentation file is created. We > > > could provide patch titles. > > > > +1 on patch titles. > > Ok, I'll solve this. Thanks. > > > But still, let's not overdo it - get something in there, see how > > > well it works, evolve it over time. > > > > > > I don't think we've heard from any (non-x86) arch maintainers? Do > > > they consider this useful at all? Poke. > > > > Yes it is. I have my own version I've cobbled together for powerpc, > > but this is much better. > > Please double check the PowerPC support matrix for correctness (if you > haven't yet): It looks good except for: > rwsem-optimized: | ok | Optimized asm/rwsem.h # arch provides optimized rwsem APIs I don't see an rwsem.h in powerpc anywhere? And this is correct but a bit confusing: > irq-time-acct: | ok | HAVE_IRQ_TIME_ACCOUNTING # arch supports precise IRQ time accounting I think you and Paul agreed it's "ok" on powerpc because we have VIRT_CPU_ACCOUNTING instead, but that's not obvious. > > I'd like to see more description in the individual files of what the > > feature is, and preferably some pointers to what's needed to > > implement it. > > Yeah, so I tried to add a short description to the feature file > itself, and for many of these features that single sentence is the > only documentation we have in the kernel source ... Yep, so that's better than what we had, and we can always improve it. cheers