From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f169.google.com (mail-qc0-f169.google.com [209.85.216.169]) by kanga.kvack.org (Postfix) with ESMTP id 81ED96B0031 for ; Thu, 6 Mar 2014 17:37:55 -0500 (EST) Received: by mail-qc0-f169.google.com with SMTP id i17so3829463qcy.28 for ; Thu, 06 Mar 2014 14:37:55 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id q1si3936728qab.111.2014.03.06.14.37.53 for ; Thu, 06 Mar 2014 14:37:54 -0800 (PST) Date: Thu, 6 Mar 2014 17:31:37 -0500 From: Rik van Riel Subject: [PATCH -mm] mm,numa,mprotect: always continue after finding a stable thp page Message-ID: <20140306173137.6a23a0b2@cuia.bos.redhat.com> In-Reply-To: <5318E4BC.50301@oracle.com> References: <5318E4BC.50301@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: David Rientjes , Andrew Morton , "linux-mm@kvack.org" , LKML , mgorman@suse.de, hhuang@redhat.com, knoel@redhat.com, aarcange@redhat.com On Thu, 06 Mar 2014 16:12:28 -0500 Sasha Levin 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 Reported-by: Sasha Levin Cc: Mel Gorman --- 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@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org