Messages in this thread | | | Date | Thu, 20 Dec 2012 10:47:07 +0000 | From | Mel Gorman <> | Subject | Re: [PATCH] compaction: fix build error in CMA && !COMPACTION |
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On Thu, Dec 20, 2012 at 02:25:30PM +0900, Minchan Kim wrote: > isolate_freepages_block and isolate_migratepages_range is used for CMA > as well as compaction so it breaks build for CONFIG_CMA && > !CONFIG_COMPACTION. > > This patch fixes it. > > Cc: Mel Gorman <mgorman@suse.de> > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > mm/compaction.c | 26 ++++++++++++++++++++------ > 1 file changed, 20 insertions(+), 6 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 5ad7f4f..70f4443 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -17,6 +17,21 @@ > #include <linux/balloon_compaction.h> > #include "internal.h" > > +#ifdef CONFIG_COMPACTION > +static inline void count_compact_event(enum vm_event_item item) > +{ > + count_vm_event(item); > +} > + > +static inline void count_compact_events(enum vm_event_item item, long delta) > +{ > + count_vm_events(item, delta); > +} > +#else > +#define count_compact_event(item) > +#define count_compact_events(item, delta) > +#endif > +
That should be
do {} while (0)
otherwise a block like this
if (foo) count_compact_event(COMPACTFREE_SCANNED) bar;
will get parsed as
if (foo) bar;
which is wrong.
Now that I look at the do {} while (0) thing it is also strictly speaking wrong for count_vm_numa_events() too because it would do the wrong thing for
count_compact_events(COMPACTFREE_SCANNED, foo++);
There happens to be no examples where we depend on such side-effects but I've taken a TODO item to fix it up in the New Year.
-- Mel Gorman SUSE Labs
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