Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757893Ab1DZRny (ORCPT ); Tue, 26 Apr 2011 13:43:54 -0400 Received: from imr4.ericy.com ([198.24.6.8]:59768 "EHLO imr4.ericy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757832Ab1DZRnx (ORCPT ); Tue, 26 Apr 2011 13:43:53 -0400 Subject: Re: [PATCH v2 3/3] thermal: Make THERMAL_HWMON implementation fully internal From: Guenter Roeck Reply-To: guenter.roeck@ericsson.com To: Jean Delvare CC: Len Brown , LKML , Rene Herman In-Reply-To: <20110426182905.72bbf7b6@endymion.delvare> References: <20110426165600.1d9ac91b@endymion.delvare> <20110426170407.3694e430@endymion.delvare> <20110426155212.GB18176@ericsson.com> <20110426182905.72bbf7b6@endymion.delvare> Content-Type: text/plain; charset="UTF-8" Organization: Ericsson Date: Tue, 26 Apr 2011 10:43:32 -0700 Message-ID: <1303839812.31666.98.camel@groeck-laptop> MIME-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2283 Lines: 49 On Tue, 2011-04-26 at 12:29 -0400, Jean Delvare wrote: > On Tue, 26 Apr 2011 08:52:12 -0700, Guenter Roeck wrote: > > On Tue, Apr 26, 2011 at 11:04:07AM -0400, Jean Delvare wrote: > > > THERMAL_HWMON is implemented inside the thermal_sys driver and has no > > > effect on drivers implementing thermal zones, so they shouldn't see > > > anything related to it in . Making the THERMAL_HWMON > > > implementation fully internal has two advantages beyond the cleaner > > > design: > > > * This avoids rebuilding all thermal drivers if the THERMAL_HWMON > > > implementation changes, or if CONFIG_THERMAL_HWMON gets enabled or > > > disabled. > > > * This avoids breaking the thermal kABI in these cases too, which > > > should make distributions happy. > > > > > > The only drawback I can see is slightly higher memory fragmentation, > > > as the number of kzalloc() calls will increase by one per thermal zone. > > > But I doubt it will be a problem in practice, as I've never seen a > > > system with more than two thermal zones. > > > > > > Signed-off-by: Jean Delvare > > > Cc: Rene Herman > > > Cc: Len Brown > > > Cc: Guenter Roeck > > > --- > > > * If memory fragmentation is really a concern to anyone, it would be > > > possible to save one kalloc for the first temperature input of each > > > zone type, as the price of slightly more complex code. > > > > > > * Removal code path is untested, as I have never been able to unload > > > the thermal_sys module on any of my systems. Something is pinning it > > > and I have no idea what it is. > > > > > Doesn't lsmod show the culprit ? > > No, it's not a module dependency. The reference counter is set to 1, > so somewhere in the kernel something is taking a reference to the > module and won't release it. I wish this was better instrumented so > that it would be possible to know who is doing that. The most likely culprit seems to be acpi. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/