From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f181.google.com (mail-yk0-f181.google.com [209.85.160.181]) by kanga.kvack.org (Postfix) with ESMTP id C186E6B0253 for ; Mon, 12 Oct 2015 11:04:12 -0400 (EDT) Received: by ykdg206 with SMTP id g206so136647312ykd.1 for ; Mon, 12 Oct 2015 08:04:12 -0700 (PDT) Received: from mail-yk0-f174.google.com (mail-yk0-f174.google.com. [209.85.160.174]) by mx.google.com with ESMTPS id g187si7971770ywe.293.2015.10.12.08.04.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Oct 2015 08:04:12 -0700 (PDT) Received: by ykey125 with SMTP id y125so14778083yke.3 for ; Mon, 12 Oct 2015 08:04:11 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1434388931-24487-1-git-send-email-aarcange@redhat.com> References: <1434388931-24487-1-git-send-email-aarcange@redhat.com> Date: Mon, 12 Oct 2015 11:04:11 -0400 Message-ID: Subject: Re: [PATCH 0/7] userfault21 update From: Patrick Donnelly Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Andrew Morton , open list , linux-mm@kvack.org, qemu-devel@nongnu.org, kvm@vger.kernel.org, Pavel Emelyanov , Sanidhya Kashyap , zhang.zhanghailiang@huawei.com, Linus Torvalds , "Kirill A. Shutemov" , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Hugh Dickins , Peter Feiner , "Dr. David Alan Gilbert" , Johannes Weiner , "Huangpeng (Peter)" Hello Andrea, On Mon, Jun 15, 2015 at 1:22 PM, Andrea Arcangeli wrote: > This is an incremental update to the userfaultfd code in -mm. Sorry I'm late to this party. I'm curious how a ptrace monitor might use a userfaultfd to handle faults in all of its tracees. Is this possible without having each (newly forked) tracee "cooperate" by creating a userfaultfd and passing that to the tracer? Have you considered using one userfaultfd for an entire tree of processes (signaled through a flag)? Would not a process id included in the include/uapi/linux/userfaultfd.h:struct uffd_msg be sufficient to disambiguate faults? -- Patrick Donnelly -- 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