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. 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") --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 477d9382f70d..bedadc686a22 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3640,7 +3640,8 @@ retry: goto got_pg; /* Checks for THP-specific high-order allocations */ - if (is_thp_gfp_mask(gfp_mask)) { + if (IS_ENABLED(CONFIG_COMPACTION) && + is_thp_gfp_mask(gfp_mask)) { /* * If compaction is deferred for high-order allocations, it is * because sync compaction recently failed. If this is the case -- 2.7.0
