From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932716AbcASJOX (ORCPT ); Tue, 19 Jan 2016 04:14:23 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:34538 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932515AbcASJOS (ORCPT ); Tue, 19 Jan 2016 04:14:18 -0500 Date: Tue, 19 Jan 2016 10:14:13 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: Borislav Petkov , Linus Torvalds , Greg Kroah-Hartman , Andrew Morton , Michal Marek , =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= , Markus Trippelsdorf , Thomas Voegtle , linux-kernel@vger.kernel.org, x86-ml , Thomas Gleixner , Jiri Olsa , Arnaldo Carvalho de Melo , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker Subject: Re: [RFC] CONFIG_FORCE_MINIMALLY_SANE_CONFIG=y (was: Re: [RFC PATCH] x86/kconfig: Sanity-check config file during oldconfig) Message-ID: <20160119091413.GA31325@gmail.com> References: <20160108133725.GH14673@pd.tnic> <568FCC45.1010301@suse.cz> <20160111194311.GF4686@pd.tnic> <20160111205945.GH4686@pd.tnic> <20160111211712.GI4686@pd.tnic> <20160114184350.GB12109@pd.tnic> <20160119082022.GB18237@gmail.com> <20160119090142.GX6357@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160119090142.GX6357@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > On Tue, Jan 19, 2016 at 09:20:22AM +0100, Ingo Molnar wrote: > > + # newer systemd silently relies on the presence of the epoll system call: > > + select EPOLL > > + select ANON_INODES > > + > > + # newer systemd silently hangs durig early init without these: > > + select PROC_SYSCTL > > + select SYSCTL > > + select POSIX_MQUEUE > > + select POSIX_MQUEUE_SYSCTL > > + > > + # systemd needs this syscall: > > + select FHANDLE > > + > > + # systemd needs devtmpfs: "systemd[1]: Failed to mount devtmpfs at /dev: No such device" > > + select DEVTMPFS > > + > > + # systemd needs tmpfs: "systemd[1]: Failed to mount tmpfs at /sys/fs/cgroup: No such file or directory" > > + select SHMEM > > + select TMPFS > > + > > + # systemd needs timerfd syscalls: "[ 8.198625] systemd[1]: Failed to create timerfd: Function not implemented^" > > + select TIMERFD > > + > > + # systemd needs signalfd support: "[ 45.536725] systemd[1]: Failed to allocate manager object: Function not implemented" > > + select SIGNALFD > > + > > + # systemd hangs during bootup without cgroup support: > > + select CGROUPS > > + > > + # systemd fails during bootup without this option, with a nonsensical message: "[DEPEND] Dependency failed for File System Check on /dev/sda1." > > + select FILE_LOCKING > > + > > + # systemd fails during bootup without this option: > > + select FSNOTIFY > > + select INOTIFY_USER > > > And yes, many of these options are members of the 'SystemD debuggability Hall Of > > Shame'... It cost me many, many days of painful config-bisection to figure the > > often obscure dependencies out, so we might as well upstream this information. > > > > Many braincells died to bring us this information! > > So why not group those under CONFIG_SYSTEMD_BLOWS? I still dont have a > machine with that turd on. I'd definitely (try to) list the reasons for each quirk in the Kconfig lines (as I did above), but I'd still keep a single generic option not tied to systemd in particular, for the following reasons: - I am using many systemd systems, so the quirks are naturally mostly systemd related. There might be more non-systemd quirks that I never triggered personally. They can be added once people trigger them. - Also, even that considered, not all of the options I listed are systemd quirks, as I still have a single (albeit simple) non-systemd test machine. - I'd like to have a single superset option that principally makes the kernel 'just work' for newbie testers - without them having to be even aware of whether their distro version uses systemd or something else. Thanks, Ingo