From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Kacur Subject: Re: [PATCH] make HWLAT_DETECTOR kernel config either disabled or a module, never builtin. Date: Tue, 22 Dec 2015 11:25:43 -0500 (EST) Message-ID: <591364261.1447150.1450801543631.JavaMail.zimbra@redhat.com> References: <20150923193340.0881074b@tor.valhalla.alchemy.lu> <20151211165240.GG6720@linutronix.de> <20151213113935.59cfd847@balder.valhalla.alchemy.lu> <20151222151117.GD27274@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Joakim Hernberg , linux-rt-users@vger.kernel.org, Thomas Gleixner , Steven Rostedt , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= To: Sebastian Andrzej Siewior Return-path: Received: from mx6-phx2.redhat.com ([209.132.183.39]:53745 "EHLO mx6-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754265AbbLVQ0E (ORCPT ); Tue, 22 Dec 2015 11:26:04 -0500 In-Reply-To: <20151222151117.GD27274@linutronix.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: ----- Original Message ----- > * Joakim Hernberg | 2015-12-13 11:39:35 [+0100]: > > >I looked at the IRC logs from when this was discussed. The hwlatdetect > >script looks for the kernel module and will fail if it's built-in (or > >compressed). Also this quote from irc: I need to look > >at the code, but offhand, I think we said, it cannot be a built-in by design > > Why can't it work by design in built-in mode? The module parameters > `enabled` and `threshold` can be set via debugfs (and via command line). > So I don't see here the difference between module and built-in. > Is there something I missed? > > If the hwlatdetect script is not able to handle that then it deserves to > be fixed. The same goes for support of compressed modules. > > >These were the reasons for the patch. > The script can be made to handle it, that's not a big deal. I think the historical reason was worrying that people could be accidentally running a kernel with some really heavy weight debugging that would affect performance. However, let people hang themselves if they want. Clark was going to send a patch to allow it, but probably ran out of time before the holidays. You can beat him to the punch if you want, or wait for him. John