Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1957184AbdDZIo1 (ORCPT ); Wed, 26 Apr 2017 04:44:27 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35968 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1955782AbdDZInr (ORCPT ); Wed, 26 Apr 2017 04:43:47 -0400 Subject: Re: [PATCH 0/5] {ioctl_}userfaultfd.2: initial updates for 4.11 To: Mike Rapoport References: <1493137748-32452-1-git-send-email-rppt@linux.vnet.ibm.com> <428a9209-e712-7067-ab11-9c35cddcd89e@gmail.com> <20170426074339.GE16837@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: <4c00c7d5-4636-f425-9bdf-8f744b8bdd63@gmail.com> Date: Wed, 26 Apr 2017 10:43:44 +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: <20170426074339.GE16837@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 Content-Length: 3449 Lines: 101 Hello Mike, On 04/26/2017 09:43 AM, Mike Rapoport wrote: > On Wed, Apr 26, 2017 at 09:23:45AM +0200, Michael Kerrisk (man-pages) wrote: >> Hello Mike, >> >> On 04/25/2017 06:29 PM, Mike Rapoport wrote: >>> Hello Michael, >>> >>> These patches are some kind of brief highlights of the changes to the >>> userfaultfd pages. >> >> Thanks for the patches. All merged. A few tweaks made, >> and pushed to Git. >> >>> The changes to userfaultfd functionality are also described at update to >>> Documentation/vm/userfaultfd.txt [1]. >>> >>> In general, there were three major additions: >>> * hugetlbfs support >>> * shmem support >>> * non-page fault events >>> >>> I think we should add some details about using userfaultfd with different >>> memory types, describe meaning of each feature bits and add some text about >>> the new events. >> >> Agreed. >> >>> I haven't updated 'struct uffd_msg' yet, and I hesitate whether it's >>> description belongs to userfaultfd.2 or ioctl_userfaultfd.2 >> >> My guess is userfaultfd.2. But, maybe I missed something. >> What suggests to you that it could be ioctl_userfaultfd.2 instead? > > I've started to add relatively elaborate descriptions of UFFD_EVENT_* to > ioctl_userfaultfd.2 and I've found that I write a lot about struct uffd_msg > fields, but the structure itself is described at userfaultfd.2. > Now, when I'm thinking about it, maybe it would be better to put the > detailed descriptions of the events in userfaultfd.2 and only brief notes > in ioctl_userfaultfd.2. Okay -- we can tune as we go along. >>> As for the userfaultfd.7 we've discussed earlier, I believe it would >>> repeat Documentation/vm/userfaultfd.txt in way, so I'm not really sure it >>> is required. >> >> The thing about kernel Doc files is they are a lot less visible. >> It would be best I think to have the user-space visible >> API fully described in man pages... > > I agree with the point about the visibility, I just don't know if > userfaultfd.7 would be required or we'll have all the necessary bits in > {ioctl_}userfaultfd.2. I'm going to add more content to the man2 pages and > then we'll see if we need man7 as well. Okay. Cheers, Michael >> Cheers, >> >> Michael >> >> >>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5a02026d390ea1bb0c16a0e214e45613a3e3d885 >>> >>> Mike Rapoport (5): >>> userfaultfd.2: describe memory types that can be used from 4.11 >>> ioctl_userfaultfd.2: describe memory types that can be used from 4.11 >>> ioctl_userfaultfd.2: update UFFDIO_API description >>> userfaultfd.2: add Linux container migration use-case to NOTES >>> usefaultfd.2: add brief description of "non-cooperative" mode >>> >>> man2/ioctl_userfaultfd.2 | 46 ++++++++++++++++++++++++++++++++++++++-------- >>> man2/userfaultfd.2 | 25 ++++++++++++++++++++++--- >>> 2 files changed, 60 insertions(+), 11 deletions(-) >>> >> >> >> -- >> Michael Kerrisk >> Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ >> Linux/UNIX System Programming Training: http://man7.org/training/ >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-man" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/