On Thu, 06 Mar 2014 16:12:28 -0500 Sasha Levin <sasha.levin@xxxxxxxxxx> wrote: > While fuzzing with trinity inside a KVM tools guest running latest -next kernel I've hit the > following spew. This seems to be introduced by your patch "mm,numa: reorganize change_pmd_range()". That patch should not introduce any functional changes, except for the VM_BUG_ON that catches the fact that we fell through to the 4kB pte handling code, despite having just handled a THP pmd... Does this patch fix the issue? Mel, am I overlooking anything obvious? :) ---8<--- Subject: mm,numa,mprotect: always continue after finding a stable thp page When turning a thp pmds into a NUMA one, change_huge_pmd will return 0 when the pmd already is a NUMA pmd. However, change_pmd_range would fall through to the code that handles 4kB pages, instead of continuing on to the next pmd. Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> --- mm/mprotect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mprotect.c b/mm/mprotect.c index 61f0a07..4746608 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -138,8 +138,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, pages += HPAGE_PMD_NR; nr_huge_updates++; } - continue; } + continue; } /* fall through, the trans huge pmd just split */ } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>