On Mon, 1 Oct 2018, Andrey Vagin wrote: > On Thu, Sep 27, 2018 at 11:41:49PM +0200, Thomas Gleixner wrote: > > On Thu, 27 Sep 2018, Thomas Gleixner wrote: > > > Add time skew via NTP/PTP into the picture and you might have to adjust > > > timers as well, because you need to guarantee that they are not expiring > > > early. > > > > > > I haven't looked through Dimitry's patches yet, but I don't see how this > > > can work at all without introducing subtle issues all over the place. > > > > And just a quick scan tells me that this is broken. Timers will expire > > early or late. The latter is acceptible to some extent, but larger delays > > might come with surprise. Expiring early is an absolute nono. > > Do you mean that we have to adjust all timers after changing offset for > CLOCK_MONOTONIC or CLOCK_BOOTTIME? Our idea is that offsets for > monotonic and boot times will be set immediately after creating a time > namespace before using any timers. I explained that in detail in this thread, but it's not about the initial setting of clock mono/boot before any timers have been armed. It's about setting the offset or clock realtime (via settimeofday) when timers are already armed. Also having a entirely different time domain, e.g. separate NTP adjustments, makes that necessary. Thanks, tglx
