Hi Andrew, After merging the akpm tree, today's linux-next build (sparc defconfig) failed like this: In file included from arch/sparc/include/asm/bug.h:20:0, from include/linux/bug.h:4, from include/linux/thread_info.h:11, from include/asm-generic/preempt.h:4, from arch/sparc/include/generated/asm/preempt.h:1, from include/linux/preempt.h:18, from include/linux/spinlock.h:50, from include/linux/mmzone.h:7, from include/linux/gfp.h:5, from include/linux/slab.h:14, from mm/mmap.c:12: mm/mmap.c: In function 'exit_mmap': mm/mmap.c:2858:46: error: 'PUD_SHIFT' undeclared (first use in this function) round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT); ^ include/asm-generic/bug.h:86:25: note: in definition of macro 'WARN_ON' int __ret_warn_on = !!(condition); \ ^ mm/mmap.c:2858:46: note: each undeclared identifier is reported only once for each function it appears in round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT); ^ include/asm-generic/bug.h:86:25: note: in definition of macro 'WARN_ON' int __ret_warn_on = !!(condition); \ ^ Caused by commit b316feb3c37f ("mm: account pmd page tables to the process"). 32 bit sparc does not seem to define PUD_SHIFT ... I am not sure what the correct fix is here, so I just did the following patch for today. From: Stephen Rothwell Date: Mon, 19 Jan 2015 19:10:53 +1100 Subject: [PATCH] mm: account pmd page tables to the process fix Signed-off-by: Stephen Rothwell --- mm/mmap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/mmap.c b/mm/mmap.c index 6a7d36d133fb..25271805ab39 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2854,8 +2854,10 @@ void exit_mmap(struct mm_struct *mm) WARN_ON(atomic_long_read(&mm->nr_ptes) > round_up(FIRST_USER_ADDRESS, PMD_SIZE) >> PMD_SHIFT); +#ifdef PUD_SHIFT WARN_ON(mm_nr_pmds(mm) > round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT); +#endif } /* Insert vm structure into process list sorted by address -- 2.1.4 -- Cheers, Stephen Rothwell sfr@canb.auug.org.au