Re: [PATCH] kernel: make rcu/tree_trace.c explicitly non-modular

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

[Re: [PATCH] kernel: make rcu/tree_trace.c explicitly non-modular] On 25/08/2015 (Tue 09:29) Josh Triplett wrote:

> On Tue, Aug 25, 2015 at 11:23:17AM -0400, Paul Gortmaker wrote:
> > The Kconfig currently controlling compilation of this code is:
> > 
> > init/Kconfig:config TREE_RCU_TRACE
> > init/Kconfig:   def_bool RCU_TRACE && ( TREE_RCU || PREEMPT_RCU )
> > 
> > ...meaning that it currently is not being built as a module by anyone.
> > 
> > Lets remove the modular code that is essentially orphaned, so that
> > when reading the file there is no doubt it is builtin-only.
> > 
> > Since module_init translates to device_initcall in the non-modular
> > case, the init ordering remains unchanged with this commit.  We could
> > consider moving this to an earlier initcall if desired.
> > 
> > We don't replace module.h with init.h since the file already has that.
> > We also delete the moduleparam.h include that is left over from
> > commit 64db4cfff99c04cd5f550357edcc8780f96b54a2 (""Tree RCU": scalable
> > classic RCU implementation") since it is not needed here either.
> > 
> > We leave some tags like MODULE_AUTHOR for documentation purposes.
> > 
> > Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
> > Cc: Josh Triplett <josh@joshtriplett.org>
> > Cc: Steven Rostedt <rostedt@goodmis.org>
> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> > Cc: Lai Jiangshan <jiangshanlai@gmail.com>
> > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> 
> Seems reasonable, though leaving the MODULE_* metadata commented out at
> the end seems odd.  I'd suggest using the DESCRIPTION to update the

That was largely driven by the desire to make as minimalist change as
possible...

> comment at the top (which is actually outdated and needs
> s/classic/hierarchical/), dropping the MODULE_LICENSE (redundant with
> the license header), and changing "MODULE_AUTHOR" into an "Author:"
> under the copyright.

...but I can also do it that way too; fine by me.  I'll wait a bit to
give Paul a chance to comment before resending, in case he also wants
some changes.

P.
--

> 
> With that:
> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> 
> > diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c
> > index 6fc4c5ff3bb5..e8a0a11e8dd7 100644
> > --- a/kernel/rcu/tree_trace.c
> > +++ b/kernel/rcu/tree_trace.c
> > @@ -33,9 +33,7 @@
> >  #include <linux/sched.h>
> >  #include <linux/atomic.h>
> >  #include <linux/bitops.h>
> > -#include <linux/module.h>
> >  #include <linux/completion.h>
> > -#include <linux/moduleparam.h>
> >  #include <linux/percpu.h>
> >  #include <linux/notifier.h>
> >  #include <linux/cpu.h>
> > @@ -487,16 +485,10 @@ free_out:
> >  	debugfs_remove_recursive(rcudir);
> >  	return 1;
> >  }
> > +device_initcall(rcutree_trace_init);
> >  
> > -static void __exit rcutree_trace_cleanup(void)
> > -{
> > -	debugfs_remove_recursive(rcudir);
> > -}
> > -
> > -
> > -module_init(rcutree_trace_init);
> > -module_exit(rcutree_trace_cleanup);
> > -
> > +/*
> >  MODULE_AUTHOR("Paul E. McKenney");
> >  MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
> >  MODULE_LICENSE("GPL");
> > +*/
> > -- 
> > 2.5.0
> >