From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f43.google.com (mail-oi0-f43.google.com [209.85.218.43]) by kanga.kvack.org (Postfix) with ESMTP id 0B58D6B0069 for ; Thu, 9 Oct 2014 06:36:07 -0400 (EDT) Received: by mail-oi0-f43.google.com with SMTP id u20so1933001oif.30 for ; Thu, 09 Oct 2014 03:36:06 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id f9si2753458oel.66.2014.10.09.03.36.05 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Oct 2014 03:36:05 -0700 (PDT) Date: Thu, 9 Oct 2014 12:35:59 +0200 From: Peter Zijlstra Subject: Re: [PATCH 1/4] mm: gup: add FOLL_TRIED Message-ID: <20141009103559.GK4750@worktop.programming.kicks-ass.net> References: <1412153797-6667-1-git-send-email-aarcange@redhat.com> <1412153797-6667-2-git-send-email-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1412153797-6667-2-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andres Lagar-Cavilla , Gleb Natapov , Radim Krcmar , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Jianyu Zhan , Paul Cassella , Hugh Dickins , Peter Feiner , "\\\"Dr. David Alan Gilbert\\\"" On Wed, Oct 01, 2014 at 10:56:34AM +0200, Andrea Arcangeli wrote: > From: Andres Lagar-Cavilla This needs a changelog.... > 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