On Thu 12-10-17 18:46:32, Steven Rostedt wrote: > From: Steven Rostedt (VMware) <rost...@goodmis.org> > > When trace events are defined but not used they still create data > structures and functions for their use, even though nothing may be > using them. > > The trace events mm_vmscan_memcg_reclaim_begin, > mm_vmscan_memcg_softlimit_reclaim_begin, mm_vmscan_memcg_reclaim_end, > and mm_vmscan_memcg_softlimit_reclaim_end are not used if CONFIG_MEMCG > is not defined. Do not create these trace events unless CONFIG_MEMCG is > defined.
I do not understand the ftrace machinery and I have to admit I was under impression that nothing really gets defined if the code using them doesn't exist but if this is not the case then this patch makes sense to me > Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> Acked-by: Michal Hocko <mho...@suse.com> > --- > Index: linux-trace.git/include/trace/events/vmscan.h > =================================================================== > --- linux-trace.git.orig/include/trace/events/vmscan.h > +++ linux-trace.git/include/trace/events/vmscan.h > @@ -133,6 +133,7 @@ DEFINE_EVENT(mm_vmscan_direct_reclaim_be > TP_ARGS(order, may_writepage, gfp_flags, classzone_idx) > ); > > +#ifdef CONFIG_MEMCG > DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, > mm_vmscan_memcg_reclaim_begin, > > TP_PROTO(int order, int may_writepage, gfp_t gfp_flags, int > classzone_idx), > @@ -146,6 +147,7 @@ DEFINE_EVENT(mm_vmscan_direct_reclaim_be > > TP_ARGS(order, may_writepage, gfp_flags, classzone_idx) > ); > +#endif /* CONFIG_MEMCG */ > > DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_end_template, > > @@ -171,6 +173,7 @@ DEFINE_EVENT(mm_vmscan_direct_reclaim_en > TP_ARGS(nr_reclaimed) > ); > > +#ifdef CONFIG_MEMCG > DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, > mm_vmscan_memcg_reclaim_end, > > TP_PROTO(unsigned long nr_reclaimed), > @@ -184,6 +187,7 @@ DEFINE_EVENT(mm_vmscan_direct_reclaim_en > > TP_ARGS(nr_reclaimed) > ); > +#endif /* CONFIG_MEMCG */ > > TRACE_EVENT(mm_shrink_slab_start, > TP_PROTO(struct shrinker *shr, struct shrink_control *sc, -- Michal Hocko SUSE Labs
