Re: [PATCH 1/4] userfaultfd.2: Add UFFD_FEATURE_THREAD_ID docs

From: Peter Xu <peterx@redhat.com>
To: "Alejandro Colomar (man-pages)" <alx.manpages@gmail.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>,
	Nadav Amit <nadav.amit@gmail.com>,
	linux-kernel@vger.kernel.org,
	Linux MM Mailing List <linux-mm@kvack.org>,
	Axel Rasmussen <axelrasmussen@google.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Michael Kerrisk <mtk.manpages@gmail.com>,
	linux-man@vger.kernel.org
Subject: Re: [PATCH 1/4] userfaultfd.2: Add UFFD_FEATURE_THREAD_ID docs
Date: Thu, 4 Mar 2021 10:50:19 -0500	[thread overview]
Message-ID: <20210304155019.GX397383@xz-x1> (raw)
In-Reply-To: <b0583d47-43ba-6077-9d93-074cd34993f3@gmail.com>

On Thu, Mar 04, 2021 at 10:22:18AM +0100, Alejandro Colomar (man-pages) wrote:
> Hello Peter,

Hi, Alex,

> 
> On 3/4/21 2:59 AM, Peter Xu wrote:
> > UFFD_FEATURE_THREAD_ID is supported since Linux 4.14.
> > 
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> >   man2/userfaultfd.2 | 12 ++++++++++++
> >   1 file changed, 12 insertions(+)
> > 
> > diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2
> > index e7dc9f813..2d14effc6 100644
> > --- a/man2/userfaultfd.2
> > +++ b/man2/userfaultfd.2
> > @@ -77,6 +77,12 @@ When the last file descriptor referring to a userfaultfd object is closed,
> >   all memory ranges that were registered with the object are unregistered
> >   and unread events are flushed.
> >   .\"
> > +.PP
> > +Since Linux 4.14, userfaultfd page fault message can selectively embed fault
> > +thread ID information into the fault message.  One needs to enable this feature
> > +explicitly using the
> > +.BR UFFD_FEATURE_THREAD_ID
> 
> This should use [.B] and not [.BR].
> .BR is for alternate Bold and Roman.
> .B is for bold.
> 
> (There are more appearances of this in the other patches.)

Yeah I got a bit confused when differenciating those two, since I also see
similar usage, e.g.:

.BR O_CLOEXEC

I'll fix all of them appeared in current patchset.  Let me know if you also
want me to fix all the existing uses of ".BR" too where ".B" would suffice.
Otherwise I won't touch them since I can't say they're wrong either (I think
most of them should generate the same output with either ".BR" or ".B" if
there's only one word?).

Thanks,

-- 
Peter Xu