From: Michael Kerrisk <mtk.manpages-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
To: Ulrich Drepper <drepper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Davide Libenzi <davidel-AhlLAIvw+VEjIGhXcJzhZg@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [patch/rfc] eventfd semaphore-like behavior
Date: Thu, 5 Feb 2009 12:49:31 +1300 [thread overview]
Message-ID: <cfd18e0f0902041549t393c76d0s635b5e8c17fee2d1@mail.gmail.com> (raw)
In-Reply-To: <a36005b50902041545qb9ce459y710bb3b9b8949b17-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Thu, Feb 5, 2009 at 12:45 PM, Ulrich Drepper <drepper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Wed, Feb 4, 2009 at 3:05 PM, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> wrote:
>> How would you recommend that userspace determine whether its kernel
>> supports this feature, bearing in mind that someone might backport this
>> patch into arbitrarily earlier kernel versions?
>
> fd = eventfd2 (CNT, EFD_SEMAPHORE);
> if (fd == -1 && errno == EINVAL)
> puts("cannot handled EFD_SEMAPHORE");
Crossed mails. Ulrich put the point more succinctly.
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git
man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html
Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html
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prev parent reply other threads:[~2009-02-04 23:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <alpine.DEB.1.10.0902041349180.6214@alien.or.mcafeemobile.com>
[not found] ` <alpine.DEB.1.10.0902041349180.6214-GPJ85BhbkB8RepQJljzAVbITYcZ0+W3JAL8bYrjMMd8@public.gmane.org>
2009-02-04 23:05 ` [patch/rfc] eventfd semaphore-like behavior Andrew Morton
[not found] ` <20090204150507.665b5b7c.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2009-02-04 23:18 ` Davide Libenzi
[not found] ` <alpine.DEB.1.10.0902041509060.6214-GPJ85BhbkB8RepQJljzAVbITYcZ0+W3JAL8bYrjMMd8@public.gmane.org>
2009-02-04 23:24 ` Andrew Morton
[not found] ` <20090204152434.c8f65d52.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2009-02-04 23:27 ` Davide Libenzi
[not found] ` <alpine.DEB.1.10.0902041526590.6214-GPJ85BhbkB8RepQJljzAVbITYcZ0+W3JAL8bYrjMMd8@public.gmane.org>
2009-02-04 23:48 ` Michael Kerrisk
2009-02-04 23:55 ` Andrew Morton
[not found] ` <20090204155514.6abbdc8f.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2009-02-04 23:59 ` Michael Kerrisk
[not found] ` <cfd18e0f0902041559l4c40d9b6k704068337a00df7a-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-02-05 0:02 ` Davide Libenzi
[not found] ` <alpine.DEB.1.10.0902041600170.6214-GPJ85BhbkB8RepQJljzAVbITYcZ0+W3JAL8bYrjMMd8@public.gmane.org>
2010-08-30 5:21 ` Michael Kerrisk
[not found] ` <AANLkTim_seWr0LZJyC+dPBy-N+_NkzTx21vte7qrwunC-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-08-30 5:24 ` Michael Kerrisk
2010-08-30 14:22 ` Davide Libenzi
2009-02-05 0:18 ` Andrew Morton
[not found] ` <20090204161816.b93a4588.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2009-02-05 0:25 ` Davide Libenzi
[not found] ` <alpine.DEB.1.10.0902041621360.6214-GPJ85BhbkB8RepQJljzAVbITYcZ0+W3JAL8bYrjMMd8@public.gmane.org>
2009-02-05 0:34 ` Andrew Morton
2009-02-05 0:26 ` Michael Kerrisk
2009-02-04 23:45 ` Ulrich Drepper
[not found] ` <a36005b50902041545qb9ce459y710bb3b9b8949b17-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-02-04 23:49 ` Michael Kerrisk [this message]
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