From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756610AbeDZOpj (ORCPT ); Thu, 26 Apr 2018 10:45:39 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:50010 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756319AbeDZOpg (ORCPT ); Thu, 26 Apr 2018 10:45:36 -0400 Message-ID: <1524753932.3226.5.camel@HansenPartnership.com> Subject: Re: [dm-devel] [PATCH v5] fault-injection: introduce kvmalloc fallback options From: James Bottomley To: Mikulas Patocka , Michal Hocko Cc: David Rientjes , dm-devel@redhat.com, eric.dumazet@gmail.com, mst@redhat.com, netdev@vger.kernel.org, jasowang@redhat.com, Randy Dunlap , linux-kernel@vger.kernel.org, Matthew Wilcox , linux-mm@kvack.org, edumazet@google.com, Andrew Morton , virtualization@lists.linux-foundation.org, David Miller , Vlastimil Babka Date: Thu, 26 Apr 2018 07:45:32 -0700 In-Reply-To: References: <20180424170349.GQ17484@dhcp22.suse.cz> <20180424173836.GR17484@dhcp22.suse.cz> <1114eda5-9b1f-4db8-2090-556b4a37c532@infradead.org> <1524694663.4100.21.camel@HansenPartnership.com> <20180426125817.GO17484@dhcp22.suse.cz> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-04-26 at 10:28 -0400, Mikulas Patocka wrote: > > On Thu, 26 Apr 2018, Michal Hocko wrote: > > > On Wed 25-04-18 18:42:57, Mikulas Patocka wrote: > > >  > > >  > > > On Wed, 25 Apr 2018, James Bottomley wrote: > > [...] > > > > Kconfig proliferation, conversely, is a bit of a nightmare from > both > > > > the user and the tester's point of view, so we're trying to > avoid it > > > > unless absolutely necessary. > > > >  > > > > James > > >  > > > I already offered that we don't need to introduce a new kernel > option and  > > > we can bind this feature to any other kernel option, that is > enabled in  > > > the debug kernel, for example CONFIG_DEBUG_SG. Michal said no and > he said  > > > that he wants a new kernel option instead. > >  > > Just for the record. I didn't say I _want_ a config option. Do not > > misinterpret my words. I've said that a config option would be > > acceptable if there is no way to deliver the functionality via > kernel > > package automatically. You haven't provided any argument that would > > explain why the kernel package cannot add a boot option. Maybe > there are > > some but I do not see them right now. > > AFAIK Grub doesn't load per-kernel options from a per-kernel file. > Even if we hacked grub scripts to add this option, other > distributions won't. Perhaps find out beforehand instead of insisting on an approach without knowing. On openSUSE the grub config is built from the files in /etc/grub.d/ so any package can add a kernel option (and various conditions around activating it) simply by adding a new file. The config files are quite sophisticated, so you can add what looks to be a new kernel, but is really an existing kernel with different options this way. James