From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb0-f197.google.com (mail-yb0-f197.google.com [209.85.213.197]) by kanga.kvack.org (Postfix) with ESMTP id 54C8A6B0262 for ; Wed, 21 Sep 2016 17:15:26 -0400 (EDT) Received: by mail-yb0-f197.google.com with SMTP id c79so84609193ybf.2 for ; Wed, 21 Sep 2016 14:15:26 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id n62si15155478ywf.291.2016.09.21.14.15.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Sep 2016 14:15:25 -0700 (PDT) From: Andrea Arcangeli Subject: [PATCH 0/4] mm: vma_merge/vma_adjust minor updates against -mm Date: Wed, 21 Sep 2016 23:15:18 +0200 Message-Id: <1474492522-2261-1-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, Rik van Riel , Hugh Dickins , Mel Gorman Hello, Here 4 more minor patches that are incremental against -mm. In short: 1/4) updates vm_page_prot atomically as it's updated outside the rmap_locks. It's always better to use READ_ONCE/WRITE_ONCE if the access is concurrent from multiple CPUs, even if there wouldn't be risk of reading intermediate values... like in this case there is too. Not critical, theoretical issue only so far, it might be possible that gcc emits right asm code already, but this is safer and forces gcc to emit the right asm code. 2/4) comment correction Not critical, noop change. 3/4) adapts CONFIG_DEBUG_VM_RB=y to cope with the case of next->vm_start reduced. Earlier that could never happen and vma->vm_end was always increased instead. validate_mm() is always called before returning from vma_adjust() and the argumented rbtree is always consistent while exercising a flood of case8. Not critical if CONFIG_DEBUG_VM_RB=n as there's no functional change in such case. Critical if you set CONFIG_DEBUG_VM_RB=y, in which case without the patch false positives are emitted. 4/4) cleanup a line that is superfluous and in turns it can confuse the reader if the reader assumes it's not superfluous. Not critical, noop change. Andrea Arcangeli (4): mm: vm_page_prot: update with WRITE_ONCE/READ_ONCE mm: vma_adjust: minor comment correction mm: vma_merge: correct false positive from __vma_unlink->validate_mm_rb mm: vma_adjust: remove superfluous confusing update in remove_next == 1 case mm/huge_memory.c | 2 +- mm/migrate.c | 2 +- mm/mmap.c | 94 +++++++++++++++++++++++++++++++++++++++++--------------- 3 files changed, 72 insertions(+), 26 deletions(-) -- 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