Re: [PATCH v2] rcu: ensure kernel/rcu/rcu.h can be sourced/used stand-alone

[Paul Gortmaker <paul.gortmaker@windriver.com>]

[Re: [PATCH v2] rcu: ensure kernel/rcu/rcu.h can be sourced/used stand-alone] On 23/02/2014 (Sun 09:27) Paul E. McKenney wrote:

> On Thu, Feb 20, 2014 at 01:00:39AM -0800, Paul E. McKenney wrote:
> > On Wed, Feb 19, 2014 at 09:02:13PM -0500, Paul Gortmaker wrote:
> > > [Re: [PATCH v2] rcu: ensure kernel/rcu/rcu.h can be sourced/used stand-alone] On 19/02/2014 (Wed 17:53) Paul E. McKenney wrote:
> > > 
> > > > On Wed, Feb 19, 2014 at 02:33:27PM -0500, Paul Gortmaker wrote:
> > > > > The kbuild test bot uncovered an implicit dependence on the
> > > > > trace header being present before rcu.h in ia64 allmodconfig
> > > > > that looks like this:
> > > > > 
> > > > > In file included from kernel/ksysfs.c:22:0:
> > > > > kernel/rcu/rcu.h: In function '__rcu_reclaim':
> > > > > kernel/rcu/rcu.h:107:3: error: implicit declaration of function 'trace_rcu_invoke_kfree_callback' [-Werror=implicit-function-declaration]
> > > > > kernel/rcu/rcu.h:112:3: error: implicit declaration of function 'trace_rcu_invoke_callback' [-Werror=implicit-function-declaration]
> > > > > cc1: some warnings being treated as errors
> > > > > 
> > > > > Looking at other rcu.h users, we can find that they all
> > > > > were sourcing the trace header in advance of rcu.h itself,
> > > > > as seen in the context of this diff.  There were also some
> > > > > inconsistencies as to whether it was or wasn't sourced based
> > > > > on the parent tracing Kconfig.
> > > > > 
> > > > > Rather than "fix" it at each use site, and have inconsistent
> > > > > use based on whether "#ifdef CONFIG_RCU_TRACE" was used or not,
> > > > > lets just source the trace header just once, in the actual consumer
> > > > > of it, which is rcu.h itself.  We include it unconditionally, as
> > > > > build testing shows us that is a hard requirement for some files.
> > > > > 
> > > > > Reported-by: kbuild test robot <fengguang.wu@intel.com>
> > > > > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> > > > 
> > > > Queued for 3.16, thank you, Paul!
> > > 
> > > Thanks!
> > > 
> > > I'm assuming you meant 3.15 -- unless of course you are allowing
> > > for an insurance policy for me possibly breaking the build.  ;)
> > 
> > Well, it does seem to be doing better in testing.  ;-)
> > 
> > I split off the stuff for the 3.15 merge window a few days back, but
> > if the lack of this patch is causing a problem, I could be talked into
> > slipping it in.
> 
> And it does seem to be doing well, so I will be putting it forward for 3.15.

Great, thanks -- there was really no rush; I'd just assumed that the
3.16 was a typo, since I personally can't plan that far ahead.  ;)

Paul.
--

> 
> 							Thanx, Paul
>