From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Kerrisk (man-pages)" Subject: Re: [PATCH 1/1] futex.2: explanation of blocking behavior Date: Sat, 11 Apr 2015 08:59:58 +0200 Message-ID: <5528C66E.8070900@gmail.com> References: <1427654900-30075-1-git-send-email-xypron.glpk@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1427654900-30075-1-git-send-email-xypron.glpk-Mmb7MZpHnFY@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Heinrich Schuchardt Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org On 03/29/2015 08:48 PM, Heinrich Schuchardt wrote: > Shorten overlong sentence. > Highlight futex(). > Tfix. Thanks, Heinrich. Applied. Cheers, Michael > Signed-off-by: Heinrich Schuchardt > --- > man2/futex.2 | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/man2/futex.2 b/man2/futex.2 > index 0644fc6..dea50ea 100644 > --- a/man2/futex.2 > +++ b/man2/futex.2 > @@ -59,16 +59,18 @@ in separate processes may be different, > the same physical address may be shared by the processes using > .BR mmap (2).) > > -When executing a futex operation that requests to block a thread, > +When executing a > +.BR futex () > +operation that requests to block a thread, > the kernel will only block if the futex word has the value that the > calling thread supplied as expected value. > The load from the futex word, the comparison with > the expected value, > and the actual blocking will happen atomically and totally > -ordered with respect to concurrently executing futex operations > -on the same futex word, > -such as operations that wake threads blocked on this futex word. > -Thus, the futex word is used to connect the synchronization in user spac > +ordered with respect to concurrently executing > +.BR futex () > +operations on the same futex word. > +Thus, the futex word is used to connect the synchronization in user space > with the implementation of blocking by the kernel; similar to an atomic > compare-and-exchange operation that potentially changes shared memory, > blocking via a futex is an atomic compare-and-block operation. > -- 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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html