On Wed, 2014-05-14 at 09:18 -0700, Darren Hart wrote: > On 5/14/14, 3:35, "Michael Kerrisk (man-pages)" <mtk.manpages@xxxxxxxxx> > wrote: > > >[So, some futex recent discussions remind me I should make this request] > > > >Hello all (especially those in the To:, namely Thomas, Darren, Ingo, > >Jakub), > > > >The futex man pages: > >http://man7.org/linux/man-pages/man2/futex.2.html > >http://man7.org/linux/man-pages/man7/futex.7.html > >are currently in a sorry state. I'm by no means convinced that all of the > >futex operations described there are explained fully and correctly. And > >probably not all error cases for each operation are properly documented. > >I'd be very happy if some folk could review those pages and send me > >corrections (Git: > >http://git.kernel.org/pub/scm/docs/man-pages/man-pages). > > > >But worse, a number of futex operations remain undocumented in futex(2) > >(see the list below). > > > >I am aware of Documentation/pi-futex.txt and > >Documentation/futex-requeue-pi.txt. However, both of those documents > >are rather thin on details / explain what certain FUTEX_* operations are > >used for rather than what they do / focus on the implementation, rather > >than the semantics. > > > >What I would like is that the futex(2) page documenta each one of > >these operations with a focus on the semantics in a way that might be > >useful to writers of library functions or those who simply wish to > >better understand (from a user-space perspective) what futexes are > >and how they are used. However, I don't have the knowledge to do > >this well in any reasonable time. > > > >Would the folk in the To: list (or anyone else who is knowledgeable) > >be willing to write patches > >(Git: http://git.kernel.org/pub/scm/docs/man-pages/man-pages ) > >or just supply me with some raw text that documents these currently > >undocumented futex operations, in the manner suggested? > > Yes, I'll be glad to help. > > However, unless I'm sorely mistaken, the larger problem is that glibc > removed the futex() call entirely, so these man pages don't describe > something users even have access to anymore. I had to revert to calling > the syscalls directly in the futextest test suite because of this: > > http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git/tree/inclu > de/futextest.h#n67 > > > Which basically defines: > > #define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \ > syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3) Yeah, and I actually stole that from you for perf :) > > Adding Carlos for his perspective. > > If I'm wrong, or we can restore the futex() call, great. If not... Should > we keep the man-pages and document it as syscall(SYS_futex, ..., op, ...) ? +1, is there anything preventing adding a futex wrapper... glibc folks? -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
