On Wed, Mar 13, 2019 at 12:18 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>
> On Sat 02-03-19 12:38:58, Yafang Shao wrote:
> > Only mm_compaction_isolate_{free, migrate}pages may be used when
> > CONFIG_COMPACTION is not set.
> > All others are used only when CONFIG_COMPACTION is set.
>
> Why is this an improvement?
>
After this change, if CONFIG_COMPACTION is not set, the tracepoints
that only work when CONFIG_COMPACTION is set will not be exposed to
the usespace.
Without this change, they will always be expose in debugfs no matter
CONFIG_COMPACTION is set or not.
That's an improvement.
> > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> > ---
> > include/trace/events/compaction.h | 6 ++----
> > 1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
> > index 6074eff..3e42078 100644
> > --- a/include/trace/events/compaction.h
> > +++ b/include/trace/events/compaction.h
> > @@ -64,6 +64,7 @@
> > TP_ARGS(start_pfn, end_pfn, nr_scanned, nr_taken)
> > );
> >
> > +#ifdef CONFIG_COMPACTION
> > TRACE_EVENT(mm_compaction_migratepages,
> >
> > TP_PROTO(unsigned long nr_all,
> > @@ -132,7 +133,6 @@
> > __entry->sync ? "sync" : "async")
> > );
> >
> > -#ifdef CONFIG_COMPACTION
> > TRACE_EVENT(mm_compaction_end,
> > TP_PROTO(unsigned long zone_start, unsigned long migrate_pfn,
> > unsigned long free_pfn, unsigned long zone_end, bool sync,
> > @@ -166,7 +166,6 @@
> > __entry->sync ? "sync" : "async",
> > __print_symbolic(__entry->status, COMPACTION_STATUS))
> > );
> > -#endif
> >
> > TRACE_EVENT(mm_compaction_try_to_compact_pages,
> >
> > @@ -195,7 +194,6 @@
> > __entry->prio)
> > );
> >
> > -#ifdef CONFIG_COMPACTION
> > DECLARE_EVENT_CLASS(mm_compaction_suitable_template,
> >
> > TP_PROTO(struct zone *zone,
> > @@ -296,7 +294,6 @@
> >
> > TP_ARGS(zone, order)
> > );
> > -#endif
> >
> > TRACE_EVENT(mm_compaction_kcompactd_sleep,
> >
> > @@ -352,6 +349,7 @@
> >
> > TP_ARGS(nid, order, classzone_idx)
> > );
> > +#endif
> >
> > #endif /* _TRACE_COMPACTION_H */
> >
> > --
> > 1.8.3.1
> >
>
> --
> Michal Hocko
> SUSE Labs
