From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [PATCH 2/2] Compile error with allmodconfig and CONFIG_PREEMPT_RT_FULL=y Date: Tue, 15 Nov 2011 06:22:19 +0100 Message-ID: <1321334539.6347.43.camel@marge.simson.net> References: <1321235083-21756-1-git-send-email-jkacur@redhat.com> <1321235083-21756-2-git-send-email-jkacur@redhat.com> <20111114165148.GB2372@linux.vnet.ibm.com> <1321303871.5011.6.camel@frodo> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: John Kacur , "Paul E. McKenney" , Thomas Gleixner , lkml , rt-users To: Steven Rostedt Return-path: Received: from mailout-de.gmx.net ([213.165.64.23]:38821 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750834Ab1KOFWZ (ORCPT ); Tue, 15 Nov 2011 00:22:25 -0500 In-Reply-To: <1321303871.5011.6.camel@frodo> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 2011-11-14 at 15:51 -0500, Steven Rostedt wrote: > On Mon, 2011-11-14 at 18:39 +0100, John Kacur wrote: > > > > On Mon, 14 Nov 2011, Paul E. McKenney wrote: > > > > > On Mon, Nov 14, 2011 at 02:44:43AM +0100, John Kacur wrote: > > > > ERROR: "in_serving_softirq" [net/sched/cls_cgroup.ko] undefined! > > > > > > > > The above can be fixed by exporting in_serving_softirq > > > > > > > > Signed-off-by: John Kacur > > > > > > > > The above patch was originally for 3.0.9-rt25 > > > > But I also needed to cherry-pick it for 3.2-rc1-rt1 > > > > --- > > > > kernel/softirq.c | 1 + > > > > 1 files changed, 1 insertions(+), 0 deletions(-) > > > > > > > > diff --git a/kernel/softirq.c b/kernel/softirq.c > > > > index 3db1d6f..5452432 100644 > > > > --- a/kernel/softirq.c > > > > +++ b/kernel/softirq.c > > > > @@ -447,6 +447,7 @@ int in_serving_softirq(void) > > > > preempt_enable(); > > > > return res; > > > > } > > > > +EXPORT_SYMBOL(in_serving_softirq); > > > > > > Why not EXPORT_SYMBOL_GPL? > > > > I have no problem with that, note however that the upstream file has > > > > EXPORT_SYMBOL(irq_stat); > > EXPORT_SYMBOL(local_bh_disable); > > EXPORT_SYMBOL(_local_bh_enable); > > EXPORT_SYMBOL(local_bh_enable); > > EXPORT_SYMBOL(local_bh_enable_ip); > > EXPORT_SYMBOL(__tasklet_schedule); > > EXPORT_SYMBOL(__tasklet_hi_schedule); > > EXPORT_SYMBOL(__tasklet_hi_schedule_first); > > EXPORT_SYMBOL(tasklet_init); > > EXPORT_SYMBOL(tasklet_kill); > > EXPORT_SYMBOL(__send_remote_softirq); > > EXPORT_SYMBOL(send_remote_softirq); > > > > Any reason we can't change all of those to EXPORT_SYMBOL_GPL?\\ > > IIRC, the point behind EXPORT_SYMBOL_GPL() is that, by using the call > you are using something that is a derivative of the code. Basically all > new functionality of the kernel is Linux specific and symbols exported > should be EXPORT_SYMBOL_GPL(). > > But, I also recall that we did not want to make things that are normal > OS operations under the EXPORT_SYMBOL_GPL(). This would include the > local_bh_enable/disable(), or anything that is called by generic > operations. For example, spin_lock() is not a GPL symbol, and if we add > some new functionality that causes all spin_locks() to call foo_bar(), > we must also make sure foo_bar() is also under just EXPORT_SYMBOL(), > otherwise, we just forced EXPORT_SYMBOL_GPL() on spin_lock(). > > Some of the above is probably just simple OS operations or are called by > static OS operation functions. > > If we go that route, we might as well make everything > EXPORT_SYMBOL_GPL(), and be damn to those that use nVidia. EXPORT_SYMBOL_GPL(migrate_disable) alone screws nVidia users, no? I have an RT user who has no other viable choice than nVidia. If the above is true, that user will end up stuck at 2.6.33-rt until we get a driver that actually works... or they deem linux to be a non-solution. -Mike