On Wed 11-05-16 16:44:07, Michal Hocko wrote: > On Wed 11-05-16 15:24:44, Arnd Bergmann wrote: > > A recent rework of the compaction code introduced a warning about > > an uninitialized variable when CONFIG_COMPACTION is disabled and > > __alloc_pages_direct_compact() does not set its 'compact_result' > > output argument: > > > > mm/page_alloc.c: In function '__alloc_pages_nodemask': > > mm/page_alloc.c:3651:6: error: 'compact_result' may be used uninitialized > > in this function [-Werror=maybe-uninitialized] > > > > This adds another check for CONFIG_COMPACTION to ensure we never > > evaluate the uninitialized variable in this configuration, which > > is probably the simplest way to avoid the warning. > > I think that hiding this into __alloc_pages_direct_compact is a better > idea. See the diff below > > > > A more elaborate rework might make this more readable. > > > > Signed-off-by: Arnd Bergmann <[email protected]> > > Fixes: 13cff7b81275 ("mm, compaction: simplify __alloc_pages_direct_compact > > feedback interface") > > Please do not use SHA for mmotm commits because they are unstable and > change each linux-next release. > > --- > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 4950d01ff935..14e3b4d93adc 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3300,6 +3300,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned > int order, > unsigned int alloc_flags, const struct alloc_context *ac, > enum migrate_mode mode, enum compact_result *compact_result) > { > + *compact_result = COMPACT_DEFERRED;
Sorry, this should have been COMPACT_SKIPPED. -- Michal Hocko SUSE Labs
