Hi Mel, Michal,

FYI, kernel build failed on memcg/since-3.5 HEAD starting from this commit:

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git since-3.5
head:   2f641f902ca76711e47e8d3b18004f0e46ca3d9b
commit: 7faeb2a39c789f1bac69014cc468677a60b73395 [184/186] mm: compaction: cache if a pageblock was scanned and no pages were isolated
config: i386-randconfig-b083 (attached as .config)

All error/warnings:

mm/compaction.c: In function 'isolation_suitable':
mm/compaction.c:60:2: error: implicit declaration of function 'get_pageblock_skip' [-Werror=implicit-function-declaration]
mm/compaction.c: In function 'reset_isolation_suitable':
mm/compaction.c:94:3: error: implicit declaration of function 'clear_pageblock_skip' [-Werror=implicit-function-declaration]
mm/compaction.c: In function 'update_pageblock_skip':
mm/compaction.c:108:3: error: implicit declaration of function 'set_pageblock_skip' [-Werror=implicit-function-declaration]
mm/compaction.c: At top level:
mm/compaction.c:68:13: warning: 'reset_isolation_suitable' defined but not used [-Wunused-function]
mm/compaction.c:177:13: warning: 'compact_capture_page' defined but not used [-Wunused-function]
cc1: some warnings being treated as errors

vim +60 mm/compaction.c
    54	static inline bool isolation_suitable(struct compact_control *cc,
    55						struct page *page)
    56	{
    57		if (cc->ignore_skip_hint)
    58			return true;
    59	
  > 60		return !get_pageblock_skip(page);
    61	}
    62	
    63	/*

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu, Yuanhan Liu                              Intel Corporation