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From: David Laight <David.Laight@ACULAB.COM>
To: "'Thomas Gleixner'" <tglx@linutronix.de>
CC: Arnd Bergmann <arnd@arndb.de>, linux-s390 <linux-s390@vger.kernel.org>,
        Mark Gross <mark.gross@intel.com>,
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        Tejun Heo <tj@kernel.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Christoph Hellwig <hch@lst.de>
Subject: RE: RFC: better timer interface
Thread-Topic: RFC: better timer interface
Thread-Index: AQHS0lW6uG7dVDC/vU6NWV3mQEk/8qH/BtCAgALEhCD///cngIAAHuQg
Date: Tue, 23 May 2017 12:51:30 +0000
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From: Thomas Gleixner
> Sent: 23 May 2017 12:59
> On Tue, 23 May 2017, David Laight wrote:
> 
> > From: Thomas Gleixner
> > > Sent: 21 May 2017 19:15
> > ...
> > > > timer_start(timer, ms, abs)
> > >
> > > I'm not even sure, whether we need absolute timer wheel timers at
> > > all, because most use cases are relative to now.
> >
> > Posix requires absolute timers for some userspace calls
> > (annoying because the code often wants relative).
> 
> Posix is completely irrelevant here. These timers are purely kernel
> internal.

Somehow pthread_cond_timedwait() has to be implemented.
Doing so without kernel timers that use absolute 'wall clock' time is tricky.

	David