From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: Re: [PATCH 05/21] userfaultfd: add vm_userfaultfd_ctx to the vm_area_struct Date: Thu, 5 Mar 2015 20:48:22 +0300 Message-ID: <54F896E6.2010800@parallels.com> References: <1425575884-2574-1-git-send-email-aarcange@redhat.com> <1425575884-2574-6-git-send-email-aarcange@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1425575884-2574-6-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli , qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Android Kernel Team Cc: "Kirill A. Shutemov" , Sanidhya Kashyap , zhang.zhanghailiang@huawei.com, Linus Torvalds , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Hugh Dickins , Peter Feiner , "Dr. David Alan Gilbert" , Christopher Covington , Johannes Weiner , Robert Love , Dmitry Adamushko , Neil Brown , Mike Hommey , Taras Glek , Jan Kara , KOSAKI Motohiro List-Id: linux-api@vger.kernel.org > diff --git a/kernel/fork.c b/kernel/fork.c > index cf65139..cb215c0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -425,6 +425,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) > goto fail_nomem_anon_vma_fork; > tmp->vm_flags &= ~VM_LOCKED; > tmp->vm_next = tmp->vm_prev = NULL; > + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; This creates an interesting effect when the userfaultfd is used outside of the process which created and activated one. If I try to monitor the memory usage of one task with another, once the first task fork()-s, its child begins to see zero-pages in the places where the monitor task was supposed to insert pages with data. > file = tmp->vm_file; > if (file) { > struct inode *inode = file_inode(file); > . > -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: Re: [PATCH 05/21] userfaultfd: add vm_userfaultfd_ctx to the vm_area_struct Date: Thu, 5 Mar 2015 20:48:22 +0300 Message-ID: <54F896E6.2010800@parallels.com> References: <1425575884-2574-1-git-send-email-aarcange@redhat.com> <1425575884-2574-6-git-send-email-aarcange@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: "Kirill A. Shutemov" , Sanidhya Kashyap , , Linus Torvalds , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Hugh Dickins , Peter Feiner , "Dr. David Alan Gilbert" , Christopher Covington , Johannes Weiner , Robert Love , Dmitry Adamushko , Neil Brown , Mike Hommey , Taras Glek , Jan Kara , KOSAKI Motohiro , , , , , , Android Kernel Team Return-path: In-Reply-To: <1425575884-2574-6-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org > diff --git a/kernel/fork.c b/kernel/fork.c > index cf65139..cb215c0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -425,6 +425,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) > goto fail_nomem_anon_vma_fork; > tmp->vm_flags &= ~VM_LOCKED; > tmp->vm_next = tmp->vm_prev = NULL; > + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; This creates an interesting effect when the userfaultfd is used outside of the process which created and activated one. If I try to monitor the memory usage of one task with another, once the first task fork()-s, its child begins to see zero-pages in the places where the monitor task was supposed to insert pages with data. > file = tmp->vm_file; > if (file) { > struct inode *inode = file_inode(file); > . > -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f180.google.com (mail-ig0-f180.google.com [209.85.213.180]) by kanga.kvack.org (Postfix) with ESMTP id 18B906B0089 for ; Thu, 5 Mar 2015 12:48:52 -0500 (EST) Received: by igal13 with SMTP id l13so47793114iga.5 for ; Thu, 05 Mar 2015 09:48:51 -0800 (PST) Received: from mx2.parallels.com (mx2.parallels.com. [199.115.105.18]) by mx.google.com with ESMTPS id 37si9273042iok.100.2015.03.05.09.48.51 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Mar 2015 09:48:51 -0800 (PST) Message-ID: <54F896E6.2010800@parallels.com> Date: Thu, 5 Mar 2015 20:48:22 +0300 From: Pavel Emelyanov MIME-Version: 1.0 Subject: Re: [PATCH 05/21] userfaultfd: add vm_userfaultfd_ctx to the vm_area_struct References: <1425575884-2574-1-git-send-email-aarcange@redhat.com> <1425575884-2574-6-git-send-email-aarcange@redhat.com> In-Reply-To: <1425575884-2574-6-git-send-email-aarcange@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli , qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Android Kernel Team Cc: "Kirill A. Shutemov" , Sanidhya Kashyap , zhang.zhanghailiang@huawei.com, Linus Torvalds , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Hugh Dickins , Peter Feiner , "Dr. David Alan Gilbert" , Christopher Covington , Johannes Weiner , Robert Love , Dmitry Adamushko , Neil Brown , Mike Hommey , Taras Glek , Jan Kara , KOSAKI Motohiro , Michel Lespinasse , Minchan Kim , Keith Packard , "Huangpeng (Peter)" , Anthony Liguori , Stefan Hajnoczi , Wenchao Xia , Andrew Jones , Juan Quintela > diff --git a/kernel/fork.c b/kernel/fork.c > index cf65139..cb215c0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -425,6 +425,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) > goto fail_nomem_anon_vma_fork; > tmp->vm_flags &= ~VM_LOCKED; > tmp->vm_next = tmp->vm_prev = NULL; > + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; This creates an interesting effect when the userfaultfd is used outside of the process which created and activated one. If I try to monitor the memory usage of one task with another, once the first task fork()-s, its child begins to see zero-pages in the places where the monitor task was supposed to insert pages with data. > file = tmp->vm_file; > if (file) { > struct inode *inode = file_inode(file); > . > -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757134AbbCERtP (ORCPT ); Thu, 5 Mar 2015 12:49:15 -0500 Received: from mx2.parallels.com ([199.115.105.18]:45674 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750965AbbCERtJ (ORCPT ); Thu, 5 Mar 2015 12:49:09 -0500 Message-ID: <54F896E6.2010800@parallels.com> Date: Thu, 5 Mar 2015 20:48:22 +0300 From: Pavel Emelyanov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Andrea Arcangeli , , , , , , Android Kernel Team CC: "Kirill A. Shutemov" , Sanidhya Kashyap , , Linus Torvalds , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Andrew Morton , Sasha Levin , Hugh Dickins , Peter Feiner , "Dr. David Alan Gilbert" , Christopher Covington , Johannes Weiner , Robert Love , Dmitry Adamushko , Neil Brown , Mike Hommey , Taras Glek , Jan Kara , KOSAKI Motohiro , Michel Lespinasse , Minchan Kim , Keith Packard , "Huangpeng (Peter)" , Anthony Liguori , Stefan Hajnoczi , Wenchao Xia , Andrew Jones , Juan Quintela Subject: Re: [PATCH 05/21] userfaultfd: add vm_userfaultfd_ctx to the vm_area_struct References: <1425575884-2574-1-git-send-email-aarcange@redhat.com> <1425575884-2574-6-git-send-email-aarcange@redhat.com> In-Reply-To: <1425575884-2574-6-git-send-email-aarcange@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [89.169.95.100] X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To US-EXCH.sw.swsoft.com (10.255.249.47) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > diff --git a/kernel/fork.c b/kernel/fork.c > index cf65139..cb215c0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -425,6 +425,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) > goto fail_nomem_anon_vma_fork; > tmp->vm_flags &= ~VM_LOCKED; > tmp->vm_next = tmp->vm_prev = NULL; > + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; This creates an interesting effect when the userfaultfd is used outside of the process which created and activated one. If I try to monitor the memory usage of one task with another, once the first task fork()-s, its child begins to see zero-pages in the places where the monitor task was supposed to insert pages with data. > file = tmp->vm_file; > if (file) { > struct inode *inode = file_inode(file); > . > From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53360) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTa6w-0005p9-Sy for qemu-devel@nongnu.org; Thu, 05 Mar 2015 13:03:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YTa6p-0000RJ-OS for qemu-devel@nongnu.org; Thu, 05 Mar 2015 13:03:02 -0500 Received: from mx2.parallels.com ([199.115.105.18]:60795) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTa6p-0000RC-II for qemu-devel@nongnu.org; Thu, 05 Mar 2015 13:02:55 -0500 Message-ID: <54F896E6.2010800@parallels.com> Date: Thu, 5 Mar 2015 20:48:22 +0300 From: Pavel Emelyanov MIME-Version: 1.0 References: <1425575884-2574-1-git-send-email-aarcange@redhat.com> <1425575884-2574-6-git-send-email-aarcange@redhat.com> In-Reply-To: <1425575884-2574-6-git-send-email-aarcange@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 05/21] userfaultfd: add vm_userfaultfd_ctx to the vm_area_struct List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrea Arcangeli , qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Android Kernel Team Cc: Robert Love , Dave Hansen , Jan Kara , Neil Brown , Stefan Hajnoczi , Andrew Jones , Sanidhya Kashyap , KOSAKI Motohiro , Michel Lespinasse , Taras Glek , zhang.zhanghailiang@huawei.com, Juan Quintela , Hugh Dickins , Mel Gorman , Sasha Levin , "Dr. David Alan Gilbert" , "Huangpeng (Peter)" , Andres Lagar-Cavilla , Christopher Covington , Anthony Liguori , Paolo Bonzini , "Kirill A. Shutemov" , Keith Packard , Wenchao Xia , Andy Lutomirski , Minchan Kim , Dmitry Adamushko , Johannes Weiner , Mike Hommey , Andrew Morton , Linus Torvalds , Peter Feiner > diff --git a/kernel/fork.c b/kernel/fork.c > index cf65139..cb215c0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -425,6 +425,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) > goto fail_nomem_anon_vma_fork; > tmp->vm_flags &= ~VM_LOCKED; > tmp->vm_next = tmp->vm_prev = NULL; > + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; This creates an interesting effect when the userfaultfd is used outside of the process which created and activated one. If I try to monitor the memory usage of one task with another, once the first task fork()-s, its child begins to see zero-pages in the places where the monitor task was supposed to insert pages with data. > file = tmp->vm_file; > if (file) { > struct inode *inode = file_inode(file); > . >