From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752151AbdDIJ5n (ORCPT ); Sun, 9 Apr 2017 05:57:43 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:35728 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751901AbdDIJ5f (ORCPT ); Sun, 9 Apr 2017 05:57:35 -0400 Date: Sun, 9 Apr 2017 11:57:32 +0200 From: Pavel Machek To: Steven Rostedt Cc: Sergey Senozhatsky , Jan Kara , "Eric W. Biederman" , Sergey Senozhatsky , Ye Xiaolong , Petr Mladek , Andrew Morton , Linus Torvalds , Peter Zijlstra , "Rafael J . Wysocki" , Greg Kroah-Hartman , Jiri Slaby , Len Brown , linux-kernel@vger.kernel.org, lkp@01.org Subject: Re: [printk] fbc14616f4: BUG:kernel_reboot-without-warning_in_test_stage Message-ID: <20170409095732.GA27363@amd> References: <20170331063913.GE20961@yexl-desktop> <20170331144730.GA10578@tigerII.localdomain> <87a881v52o.fsf@xmission.com> <20170403093152.GB15168@quack2.suse.cz> <20170406173306.GD10363@amd> <20170407044334.GA487@jagdpanzerIV.localdomain> <20170407071558.GA11792@amd> <20170407074634.GB1091@jagdpanzerIV.localdomain> <20170407081449.GA12859@amd> <20170407102917.3121e9f0@gandalf.local.home> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jI8keyz6grp/JLjh" Content-Disposition: inline In-Reply-To: <20170407102917.3121e9f0@gandalf.local.home> 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 --jI8keyz6grp/JLjh Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri 2017-04-07 10:29:17, Steven Rostedt wrote: > On Fri, 7 Apr 2017 10:14:49 +0200 > Pavel Machek wrote: >=20 > > > serial console can be quite slow. and port->lock, that is acquired by > > > console_unlock()->call_console_drivers()->write(), is also accessible > > > by serial driver's IRQ handler, and this lock may be busy long > > > enough -- as long as that IRQ handler transmits/receives chars. but > > > that's not the point. =20 > >=20 > > Well. This is what we had for 20 years. >=20 > But for the last 20 years we were not booting on machines with over 200 > CPUs. Well, we were, but those had custom kernels (which probably > dismantled printk). Well, not a problem. Just find a solution that works for dual core machines as well as it did for 20 years. 2 seconds timeout as proposed earlier should work well for big machines, and with no regressions on small machines. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --jI8keyz6grp/JLjh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAljqBYwACgkQMOfwapXb+vJgRQCeO9d+nbo3Y24Kh6aYc1QqXYlW di8AniaSW56cz8Cr+OaaO7g/2r5gqhvt =AcKJ -----END PGP SIGNATURE----- --jI8keyz6grp/JLjh--