From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: Futex manpages out of date Date: Fri, 15 Jan 2010 18:14:51 +0100 Message-ID: <1263575691.4244.446.camel@laptop> References: <4B509EA1.8060509@us.ibm.com> <1263575484.4244.445.camel@laptop> <4B50A228.8070401@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4B50A228.8070401-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Darren Hart Cc: Michael Kerrisk , linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Thomas Gleixner , Ingo Molnar , Eric Dumazet , Dinakar Guniguntala , John Stultz , John Kacur List-Id: linux-man@vger.kernel.org On Fri, 2010-01-15 at 09:13 -0800, Darren Hart wrote: > Peter Zijlstra wrote: > > On Fri, 2010-01-15 at 08:58 -0800, Darren Hart wrote: > >> The futex man-pages (2,7) from version 3.15-1 and at least a few earlier > >> versions are considerably out of date with respect to the current > >> implementation. They don't document newer op codes, such as: > >> > >> FUTEX_WAIT_BITSET > >> FUTEX_WAKE_BITSET > >> FUTEX_WAKE_OP > >> FUTEX_LOCK_PI > >> FUTEX_UNLOCK_PI > >> FUTEX_WAIT_REQUEUE_PI > >> FUTEX_CMP_REQUEUE_PI > >> > >> These new wait op codes now use absolute timeouts, while the original > >> FUTEX_WAIT uses a relative timeout. Lastly, and most importantly, glibc > >> has removed the futex() wrapper to syscall(SYS_futex, ...). With that in > >> mind, would people prefer that we simply remove the futex man-pages > >> (2,7)? > > > > A readable text about the interaction between the futex value and the > > various futex ops and how to build proper locking primitives with them > > would be helpful I think, however doing that in the form of a locking > > library (as has been suggested at KS) seems plenty fine to me. > > > > Readable code is much better than rambling English at conveying this > > stuff. > > Perhaps as part of futex-test? An example set of locking primitives > would be a good way to test the syscall independently of glibc... Sure, and if that ever grows into what benh wants then we're good I think ;-) -- 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