From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f48.google.com (mail-qa0-f48.google.com [209.85.216.48]) by kanga.kvack.org (Postfix) with ESMTP id 363746B0069 for ; Wed, 1 Oct 2014 04:57:17 -0400 (EDT) Received: by mail-qa0-f48.google.com with SMTP id dc16so111098qab.7 for ; Wed, 01 Oct 2014 01:57:16 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id q8si556500qgq.4.2014.10.01.01.57.16 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Oct 2014 01:57:16 -0700 (PDT) From: Andrea Arcangeli Subject: [PATCH 1/4] mm: gup: add FOLL_TRIED Date: Wed, 1 Oct 2014 10:56:34 +0200 Message-Id: <1412153797-6667-2-git-send-email-aarcange@redhat.com> In-Reply-To: <1412153797-6667-1-git-send-email-aarcange@redhat.com> References: <1412153797-6667-1-git-send-email-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andres Lagar-Cavilla , Gleb Natapov , Radim Krcmar , Paolo Bonzini , Rik van Riel , Peter Zijlstra , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Jianyu Zhan , Paul Cassella , Hugh Dickins , Peter Feiner , "\\\"Dr. David Alan Gilbert\\\"" From: Andres Lagar-Cavilla Reviewed-by: Radim KrA?mA!A? Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Andrea Arcangeli --- include/linux/mm.h | 1 + mm/gup.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 8981cc8..0f4196a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1985,6 +1985,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma, #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */ +#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */ typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/gup.c b/mm/gup.c index 91d044b..af7ea3e 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -281,6 +281,10 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma, fault_flags |= FAULT_FLAG_ALLOW_RETRY; if (*flags & FOLL_NOWAIT) fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT; + if (*flags & FOLL_TRIED) { + VM_WARN_ON_ONCE(fault_flags & FAULT_FLAG_ALLOW_RETRY); + fault_flags |= FAULT_FLAG_TRIED; + } ret = handle_mm_fault(mm, vma, address, fault_flags); if (ret & VM_FAULT_ERROR) { -- 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