From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751453AbdEBUXi (ORCPT ); Tue, 2 May 2017 16:23:38 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:32958 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750710AbdEBUXd (ORCPT ); Tue, 2 May 2017 16:23:33 -0400 Subject: Re: [PATCH man-pages 1/5] ioctl_userfaultfd.2: update description of shared memory areas To: Mike Rapoport References: <1493617399-20897-1-git-send-email-rppt@linux.vnet.ibm.com> <1493617399-20897-2-git-send-email-rppt@linux.vnet.ibm.com> <7ec5dfc0-9d84-e142-bfaa-d96383acbee9@gmail.com> <20170502093110.GA5910@rapoport-lnx> Cc: mtk.manpages@gmail.com, Andrea Arcangeli , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-man@vger.kernel.org From: "Michael Kerrisk (man-pages)" Message-ID: <1586d8ea-342c-c652-86f4-a7fafc8c7be6@gmail.com> Date: Tue, 2 May 2017 22:23:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20170502093110.GA5910@rapoport-lnx> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/02/2017 11:31 AM, Mike Rapoport wrote: > On Mon, May 01, 2017 at 08:33:31PM +0200, Michael Kerrisk (man-pages) wrote: >> Hello Mike, >> >> I've applied this patch, but have a question. >> >> On 05/01/2017 07:43 AM, Mike Rapoport wrote: >>> Signed-off-by: Mike Rapoport >>> --- >>> man2/ioctl_userfaultfd.2 | 13 +++++++++++-- >>> 1 file changed, 11 insertions(+), 2 deletions(-) >>> >>> diff --git a/man2/ioctl_userfaultfd.2 b/man2/ioctl_userfaultfd.2 >>> index 889feb9..6edd396 100644 >>> --- a/man2/ioctl_userfaultfd.2 >>> +++ b/man2/ioctl_userfaultfd.2 >>> @@ -181,8 +181,17 @@ virtual memory areas >>> .TP >>> .B UFFD_FEATURE_MISSING_SHMEM >>> If this feature bit is set, >>> -the kernel supports registering userfaultfd ranges on tmpfs >>> -virtual memory areas >>> +the kernel supports registering userfaultfd ranges on shared memory areas. >>> +This includes all kernel shared memory APIs: >>> +System V shared memory, >>> +tmpfs, >>> +/dev/zero, >>> +.BR mmap(2) >>> +with >>> +.I MAP_SHARED >>> +flag set, >>> +.BR memfd_create (2), >>> +etc. >>> >>> The returned >>> .I ioctls >> >> Does the change in this patch represent a change that occurred in >> Linux 4.11? If so, I think this needs to be said explicitly in the text. > > The patch only extends the description of UFFD_FEATURE_MISSING_SHMEM. The > feature is indeed available from 4.11, but that is said a few lives above > (line 136 in ioctl_userfaultfd.2) Okay -- thanks for the clarification. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/