Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

From	Thomas Gleixner <tglx@linutronix.de>
Newsgroups	linux.kernel
Subject	Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op
Date	2016-07-06 21:10 +0200
Message-ID	<rS0mR-4Im-17@gated-at.bofh.it> (permalink)
References	(4 earlier) <rNdb4-2hy-41@gated-at.bofh.it> <rNfwe-45d-15@gated-at.bofh.it> <rNgBX-4Mw-11@gated-at.bofh.it> <rNhy1-5wH-3@gated-at.bofh.it> <rNhRn-5Ej-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote:
> On 06/23/2016 08:28 PM, Darren Hart wrote:
> > And as a follow-on, what is the reason for FUTEX_LOCK_PI only using
> > CLOCK_REALTIME? It seems reasonable to me that a user may want to wait a
> > specific amount of time, regardless of wall time.
> 
> Yes, that's another weird inconsistency.

The reason is that phtread_mutex_timedlock() uses absolute timeouts based on
CLOCK_REALTIME. glibc folks asked to make that the default behaviour back then
when we added LOCK_PI.

Thanks,

	tglx

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op Thomas Gleixner <tglx@linutronix.de> - 2016-06-23 19:30 +0200
  Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op Darren Hart <dvhart@infradead.org> - 2016-06-23 20:30 +0200
    Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2016-06-23 20:50 +0200
      Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op Darren Hart <dvhart@infradead.org> - 2016-06-23 22:00 +0200
        Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op Darren Hart <dvhart@infradead.org> - 2016-06-23 22:40 +0200
          Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op Thomas Gleixner <tglx@linutronix.de> - 2016-06-24 12:00 +0200
            Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2016-06-24 12:10 +0200
      Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op Thomas Gleixner <tglx@linutronix.de> - 2016-07-06 21:10 +0200

csiph-web