From: David Laight <David.Laight@ACULAB.COM>
To: 'Willem de Bruijn' <willemdebruijn.kernel@gmail.com>,
Matthew Wilcox <willy@infradead.org>
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
"Soheil Hassas Yeganeh" <soheil.kdev@gmail.com>,
Arnd Bergmann <arnd@arndb.de>, "Shuo Chen" <shuochen@google.com>
Subject: RE: [PATCH v2] epoll: add nsec timeout support
Date: Mon, 16 Nov 2020 17:11:24 +0000 [thread overview]
Message-ID: <eead2765ea5e417abe616950b4e5d02f@AcuMS.aculab.com> (raw)
In-Reply-To: <CA+FuTSdifgNAYe4DAfpRJxCO08y-sOi=XhOeMhd9mKbA3aPOug@mail.gmail.com>
From: Willem de Bruijn
> Sent: 16 November 2020 17:01
>
> On Mon, Nov 16, 2020 at 11:19 AM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Mon, Nov 16, 2020 at 11:10:01AM -0500, Willem de Bruijn wrote:
> > > diff --git a/include/uapi/linux/eventpoll.h b/include/uapi/linux/eventpoll.h
> > > index 8a3432d0f0dc..f6ef9c9f8ac2 100644
> > > --- a/include/uapi/linux/eventpoll.h
> > > +++ b/include/uapi/linux/eventpoll.h
> > > @@ -21,6 +21,7 @@
> > >
> > > /* Flags for epoll_create1. */
> > > #define EPOLL_CLOEXEC O_CLOEXEC
> > > +#define EPOLL_NSTIMEO 0x1
> > >
> > > /* Valid opcodes to issue to sys_epoll_ctl() */
> > > #define EPOLL_CTL_ADD 1
> >
> > Not a problem with your patch, but this concerns me. O_CLOEXEC is
> > defined differently for each architecture, so we need to stay out of
> > several different bits when we define new flags for EPOLL_*. Maybe
> > this:
> >
> > /*
> > * Flags for epoll_create1. O_CLOEXEC may be different bits, depending
> > * on the CPU architecture. Reserve the known ones.
> > */
> > #define EPOLL_CLOEXEC O_CLOEXEC
> > #define EPOLL_RESERVED_FLAGS 0x00680000
> > #define EPOLL_NSTIMEO 0x00000001
>
> Thanks. Good point, I'll add that in v3.
You could also add a compile assert to check that the flag is reserved.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-11-16 17:11 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-16 16:10 [PATCH v2] epoll: add nsec timeout support Willem de Bruijn
2020-11-16 16:12 ` Soheil Hassas Yeganeh
2020-11-16 16:19 ` Matthew Wilcox
2020-11-16 17:00 ` Willem de Bruijn
2020-11-16 17:11 ` David Laight [this message]
2020-11-16 19:54 ` Willem de Bruijn
2020-11-16 20:00 ` Matthew Wilcox
2020-11-16 20:04 ` Andrew Morton
2020-11-16 23:36 ` Willem de Bruijn
2020-11-16 23:51 ` Willem de Bruijn
2020-11-17 0:37 ` Andrew Morton
2020-11-17 2:21 ` Willem de Bruijn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=eead2765ea5e417abe616950b4e5d02f@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=shuochen@google.com \
--cc=soheil.kdev@gmail.com \
--cc=viro@zeniv.linux.org.uk \
--cc=willemdebruijn.kernel@gmail.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).